Dr. Jeff Masters' WunderBlog

Late February storms put only a slight dent in U.S. drought

By: JeffMasters, 4:14 PM GMT on February 28, 2013

Abundant moisture from heavy rains and snows that fell during two major Midwest storms in late February put only a slight dent in the great Midwest drought of 2012 - 2013. According to the February 28, 2013 Drought Monitor, the percentage area of the contiguous U.S. suffering moderate or greater drought shrank from 56% to 54%, and the area in the worst category of drought--exceptional drought--fell from 6.7% to 5.4% over the past week. These are the largest 1-week improvements in these drought categories that we've seen for 9 months and 15 months, respectively. The improvements were most noteworthy in Oklahoma, the Texas Panhandle, and the Southeast U.S., where drought improved by a full category (using the level 1 to 4 categories of the Palmer Drought Severity Index.) However, the dry pattern that has been dominant over the U.S. for most of the past year will re-assert itself during the coming ten days, and most of the drought region will receive less than 0.5" of precipitation through March 9. There exists the possibility of a significant Midwest storm on March 10, according to recent runs of the GFS and ECMWF computer models, but it is too early to assess if this storm may be able to provide significant drought relief. In general, droughts are more likely in the Midwest U.S. when warmer than average ocean temperatures prevail in the tropical Atlantic, with cooler than average ocean temperatures in the tropical Eastern Pacific (La Niña-like conditions.) This is what we had in during most of 2012, and continue to have in 2013. Equatorial East Pacific ocean temperatures are currently 0.5°C below average. This is similar to the ocean temperatures seen in the spring of 2012, just before the Great Drought of 2012 began. Most of the U.S. drought region needs 3 - 9" of precipitation to pull out of drought. Unless the Midwest receives a top-ten percent wettest spring on record, drought is going to be a huge concern as we enter summer.


Figure 1. Drought conditions as of February 28, 2013 showed that drought still gripped a majority of the U.S. Image credit: U.S. Drought Monitor.


Figure 2. Predicted 7-day precipitation for the period ending Thursday, March 7. Less than 10% of the U.S. drought regions are predicted to receive as much as 0.5" of precipitation (dark green color.) Image credit: NOAA/HPC.

Jeff Masters

Drought Q Rocky Plato Orko

Updated: 4:16 PM GMT on February 28, 2013

Permalink

Category 1 Rusty hits Australia; Chicago gets its biggest snow of the winter

By: JeffMasters, 3:53 PM GMT on February 27, 2013

Tropical Cyclone Rusty rumbled ashore over the coast of northwest Australia near 06 UTC (1 am EST) on Wednesday near the small town of Pardoo, about 110 km east of the largest city in the region, Port Hedland. Rusty peaked at Category 2 strength with 110 mph winds about 12 hours before landfall, but weakened to a Category 1 storm with 90 mph winds as it approached the coast, due to interaction with land. Sustained winds as high as 55 mph, gusting to 74 mph, were observed observed at the Port Hedland airport as Rusty made its approach. Rusty has dumped over 7" of rain on the coast, and major flooding is expected on area rivers. No casualties and only minor damage have been reported thus far, and I expect total damage from the storm will be less than $100 million. Rusty is the strongest tropical cyclone to affect Australia so far in the 2012 - 2013 tropical cyclone season.


Figure 1. Tropical Cyclone Rusty at 03:40 UTC on February 27, 2013 as seen by NASA's Terra satellite. At the time, Rusty was two hours from making landfall on the northwest Australian coast near Pardoo as a Category 1 storm with sustained 90 mph winds. Image credit: NASA.


Figure 2. Radar image of Rusty showing the large cloud-free eye bumping up against the coast of Australia near Pardoo at 05:40 UTC (12:40 am EST) on Wednesday, February 27. image credit: Bureau of Meteorology.

Significant snowstorm continues over Midwest U.S.
Meanwhile, back in the U.S., the second major winter storm in a week continues to blanket the Midwest with significant snows. The snowstorm, dubbed "Rocky", gave Chicago 5.4" of snow, its heaviest snowfall of what has been a quiet winter. According to the latest NOAA Storm Summary, the heaviest snow in the Midwest from Rocky fell in the Texas Panhandle, where 21" was measured in Follett. While the precipitation from the two major winter storms during the past week will not come anywhere close to busting the Midwest drought, the moisture they dropped is probably worth billions to agriculture.


Figure 3. Two-day snowfall amounts from Winter Storm Rocky.

Jeff Masters

Hurricane Winter Weather

Permalink

Category 1 Rusty drenching Australia; major winter storm hits Midwest U.S.

By: JeffMasters, 4:06 PM GMT on February 26, 2013

Tropical Cyclone Rusty is intensifying as it remains nearly stationary off the coast of northwest Australia, and poses a dangerous heavy rainfall threat to the coast. Rusty peaked at Category 1 strength with 85 mph winds on Monday at 18 UTC, then weakened to 75 mph by 06 UTC on Tuesday, due to a combination of dry wrapping into the center, interaction with land, and the storm's slow movement allowing it to upwell cooler waters from down deep. However, recent satellite loops show that Rusty's eyewall clouds now have colder tops, and the eye has shrunk, indicating that the storm is strengthening. A 7 am EST satellite intensity estimate from NOAA put Rusty at Category 2 strength with 105 mph winds. The storm may intensify even more, thanks to low wind shear of 5 - 10 knots and near-record warm ocean temperatures of 31 - 32°C (88 - 90°F). It's not often that a tropical cyclone gets 31 - 32°C waters to feed off of; these temperature are about 1.5°C (2.7°F) warmer than average for this time of year. Rusty is very close to the coast, though, and doesn't have much time to intensify further. The storm is predicted to make landfall near Port Hedland (population 15,000), on Wednesday between 06 UTC and 12 UTC (1 am - 7 am EST in the U.S.) Port Hedland is Australia's top iron ore export port, which is ironic, considering that a storm named "Rusty" has now shut down the port. With its slow movement, large circulation, and near-record warm waters to feed off, Rusty is going to dump some prodigious rains on the coast of northwestern Australia over the next few days. Radar out of Port Hedland shows very heavy rains have been affecting the coast all day, and sustained winds as high as 55 mph, gusting to 74 mph, have been observed at the Port Hedland airport. Rusty is also capable of causing considerable wind and storm surge damage, and evacuations have been ordered in low-lying areas of Port Hedland. Rusty is the strongest tropical cyclone to affect Australia in the 2012 - 2013 tropical cyclone season.


Figure 1. Tropical Cyclone Rusty at 0545 UTC on February 26, 2013 as seen by NASA's Aqua satellite. At the time, Rusty was a Category 1 storm with sustained 75 mph winds. Image credit: NASA.


Figure 2. Radar image of Rusty showing the large cloud-free eye and an intense band of precipitation to its southwest moving ashore over the coast of Australia near Port Hedland. image credit: Bureau of Meteorology.

Major blizzard pummels Midwest U.S.
Meanwhile, back in the U.S., the second major winter storm in a week is blasting the Midwest with heavy snow and high winds. The snowstorm, dubbed "Rocky", ended this morning in Wichita, Kansas, which got 6.8" of snow. When combined with heavy snows that fell in last week's storm, the 21.0" inches of snow in February 2013 now ranks as Wichita's snowiest month in its history, breaking the old record of 20.5" set exactly 100 years ago in February 1913. The 19" of snow that fell on Amarillo, Texas over a 24 hours period ending yesterday (February 25) was that city's second greatest 1-day snowfall on record, says wunderground's weather historian Christopher C. Burt in his latest blog post. A band of very heavy snow of up to 3" per hour set up over the airport for several hours, accompanied by lightning and thunder. Thundersnow was also reported in Versailles, Illinois this morning, bringing 3" of snow in just 30 minutes. Wunderblogger Lee Grenci has a detailed post on thundersnow, and analyzes the thundersnow episode that occurred during last week's snowstorm ("Q") over the Midwest. The 19" of snow that fell on Amarillo yesterday was equivalent to 1.48" of rain, making Monday the wettest day in the city in over two years (November 11, 2010 was the last time the city got so much precipitation.) While the precipitation from the two major winter storms during the past week will not come anywhere close to busting the Midwest drought, the value of this moisture runs into the billions of dollars for the parched fields and aquifers of the Midwest.


Figure 3. Snowfall amounts from Winter Storm Rocky.

Jeff Masters

Hurricane Winter Weather

Updated: 4:11 PM GMT on February 26, 2013

Permalink

Category 1 Rusty Australia's strongest tropical cyclone of 2013

By: JeffMasters, 1:36 PM GMT on February 25, 2013

Australia's most dangerous tropical cyclone of the season so far is Tropical Cyclone Rusty, which has intensified to Category 1 strength and is lumbering southeastwards towards the northwestern coast of Australia at 6 mph. Rusty is expected to intensify further into a powerful Category 3 storm, and is predicted to make landfall near the town of Port Hedland (population 15,000) on Tuesday near 18 UTC (1 pm EST in the U.S.) Rusty formed on Saturday evening when westerly winds blowing near the Equator combined with easterly winds blowing south of New Guinea to create an unusually large tropical storm with a huge, 100-mile diameter cloud-free center. Ordinarily, a storm this large takes a long time to wind up, but Rusty intensified quickly, taking advantage of low wind shear of 5 - 10 knots, and near-record warm ocean temperatures of 31 - 32°C (88 - 90°F). It's not often that a tropical cyclone gets 31 - 32°C waters to feed off of; these temperature are about 1.5°C (2.7°F) warmer than average for this time of year. The hot ocean temperatures are largely due to Australia's hottest month in its history--the nationally-averaged monthly maximum temperature during January 2013 was the highest ever recorded. For the waters off the northwest Australian coast (15°S - 20°S, 115°E - 120°E), only two years since ocean temperature records began in 1960 have seen February ocean temperatures this warm (1.57°C above average in 2005, and 1.62°C above average in 1983.) The warm waters also extend to great depth; the tropical cyclone heat potential (TCHP) in this region is over 90 kJ/cm**2, a value commonly associated with rapid intensification. With its slow movement, large circulation, and near-record warm waters to feed off, Rusty is going to dump some prodigious rains on the coast of northwestern Australia over the next few days. Radar out of Port Hedland shows very heavy rains already affecting the coast, and sustained wind as high as 38 mph have been observed there today.


Figure 1. Radar image of Rusty showing the large cloud-free center and an intense band of precipitation to it southwest moving ashore over the coast of Australia near Port Hedland. image credit: Bureau of Meteorology.


Figure 2. Tropical Cyclone Rusty at 0555 UTC on February 24, 2013 as seen by NASA's Aqua satellite. At the time, Rusty was a tropical storm with 50 mph winds, and had an usually large cloud-free center more than 100 miles in diameter. Image credit: NASA.

Rusty the strongest tropical cyclone to affect Australia so far in 2013
It's been a rather quiet tropical cyclone season for Australia so far in 2012 - 2013; only two weak tropical storms have hit the country. Tropical Cyclone Peta hit the northwest coast on January 23 as a tropical storm with 45 mph winds. Peta dumped heavy rains of 4 - 10" (102 - 254 mm) in the Port Hedland area, very close to where Rusty is expected to make landfall. Peta's rains caused widespread flooding but no major damage. More serious were the rains from the remnants of Tropical Cyclone Oswald, which hit the Queensland coast in Northeast Australia on January 21 as a tropical storm with 40 mph winds. The remnants of Oswald pushed southwards along the coast and generated record rains that caused massive flooding in Queensland. Six people died and damage was estimated at $2.5 billion. The heaviest rains fell near Tully, where approximately 1 meter (39") of rain fell in 48 hours.


Figure 3. Tropical Cyclone Oswald at 0425 UTC on January 21, 2013. Oswald hit Queensland, Australia as a tropical storm with 40 mph winds. Image credit: NASA.

Jeff Masters

Hurricane

Permalink

January 2013 Earth's 9th warmest on record; Category 2 Haruna hits Madagascar

By: JeffMasters, 5:33 PM GMT on February 22, 2013

January 2013 was the globe's 9th warmest January since records began in 1880, said National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC) on Thursday. January 2013 global land temperatures were the 13th warmest on record, and global ocean temperatures were the 8th warmest on record. January 2013 was the 335th consecutive month with global temperatures warmer than the 20th century average and the 37th straight warmer-than-average January. The last time Earth had a below-average January global temperature was in 1976, and the last below-average month of any kind was February 1985, so no one under the age of 28 has ever seen a month with below-average global temperatures. Global satellite-measured temperatures in January 2013 for the lowest 8 km of the atmosphere were 4th or 2nd warmest in the 35-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. The Northern Hemisphere snow cover extent during January 2013 was the sixth largest on record for the month, and marked the sixth consecutive January with above-average snow cover for the hemisphere. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of January 2013 in his January 2013 Global Weather Extremes Summary. The most extreme weather on the planet in January occurred in Australia, where the nationally-averaged monthly maximum temperature was the highest ever recorded. Australia also suffered record rains and flooding along the east coast due to the remains of Tropical Cyclone Oswald. Damage from the flooding totaled $2.5 billion, according to AON Benfield. One other billion-dollar weather disaster occurred in January--flooding in Indonesia that cost $3.3 billion and took 41 lives. As much as 300 millimeters (12 inches) of precipitation fell over a two-week period.


Figure 1. Departure of temperature from average for January 2013, the 9th warmest January for the globe since record keeping began in 1880. Colder than average conditions occurred in the Western U.S., northern Canada, and northern Russia. The Southern Hemisphere was record warm over land for the second month in a row, with record high monthly temperatures observed over northeastern Brazil, much of southern Africa, and northern and central Australia. No land areas in the Southern Hemisphere were cooler than average. Image credit: National Climatic Data Center (NCDC) .


Figure 2. Central Jakarta, Indonesia flooded following a heavy rain on Thursday, Jan. 17, 2013. Damage to Jakarta and surrounding areas was estimated at $3.3 billion. Image credit: AP.


Figure 3. In this photo provided by the New South Wales Rural Fire Service a wildfire near Deans Gap, Australia, crosses the Princes Highway Tuesday, Jan. 8, 2013. (AP Photo/NSW Rural Fire Service, James Morris)

Neutral El Niño conditions continue in the Pacific
For the 10th month in row, neutral El Niño conditions existed in the equatorial Pacific during January 2013. NOAA's Climate Prediction Center (CPC) expects neutral El Niño conditions to last through spring. Temperatures in the equatorial Eastern Pacific need to be 0.5°C below average or cooler for three consecutive for a La Niña episode to be declared; sea surface temperatures were 0.3°C below average as of February 18, and have ranged from 0.3 - 0.6°C below average during 2013.

Arctic sea ice falls to 6th lowest January extent on record
Arctic sea ice extent during January reached its sixth lowest extent in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). This was the 19th consecutive January and 140th consecutive month with below-average Arctic sea ice extent. The last ten years (2004 to 2013) have seen the ten lowest January extents in the satellite record.



Figure 4. Ice fractures in the Arctic sea ice off the coast of Alaska, as seen by the AVHRR instrument on NOAA's F-16 polar orbiting satellite on February 21, 2013. As discussed at the Arctic Sea Ice Blog, these sort of fractures are due to the thin first-year ice not being able to withstand the stresses put on the ice pack by strong winds. In previous winters when thick, multi-year ice abounded, these sort of fractures were much less common. Image credit: Environment Canada.

Category 2 Haruna hits Madagascar
Tropical Cyclone Haruna hit southwest Madagascar at 00 UTC Friday, February 22, as a Category 2 storm with 105 mph winds. Haruna was the strongest tropical cyclone to make landfall so far in 2013, globally. Haruna is being blamed for one death so far, and will bring torrential rains and dangerous flooding to southern Madagascar over the weekend.


Figure 5. Tropical Cyclone Haruna over Madagascar at 11:05 UTC February 22, 2013. At the time, Haruna was a Category 1 storm with 90 mph winds. Image credit: NASA.

Japan sets snow depth record
Incredible snows fell in Japan this week, bringing the amount of snow on the ground to an astonishing 5.15 meters (16.9') at Sukayu Onsen, Aomori on Honshu Island. Wunderground weather historian Christopher C. Burt details the record in his post, Record Snow Depth (for an official site) Measured in Japan.

Wunderground's climate change blogger, Dr. Ricky Rood, has a post well-worth reading, Should We Just Adapt to Climate Change?

Have a great weekend, everyone!

Jeff Masters

Climate Summaries Hurricane

Permalink

Largest winter storm of the season helping dent Midwest drought

By: JeffMasters, 3:00 PM GMT on February 21, 2013

The largest snowstorm of the winter for the Midwest drought region is winding up, and promises to bring more than a foot of snow to portions of Kansas and Nebraska. Rain and snow from the storm--dubbed Winter Storm "Q"--will put a noticeable dent in the Great Drought of 2012 - 2013 over the Midwest. A second storm due to move through the region on Monday will provide a bit of additional help. The twin storms promise to drop more than an inch of rain (or liquid equivalent rain, for regions like Kansas and Nebraska getting heavy snow.) Many areas of the drought region should enjoy their their wettest day in months on Thursday. The core drought region in the Midwest needs 3 - 9 inches of precipitation to end the drought, so the 1" of precipitation expected from the two storms will merely dent the drought, not end it. Still, the economic value of the rain and snow from the two storms is in the billions of dollars. In addition, runoff from the storms will insure that barge traffic on the Mississippi River will be able to operate well into summer. The Mississippi River at St. Louis is currently about 7' above the lowest water level on record, up over six feet from the near record-low levels of early January.


Figure 1. Predicted precipitation for the 5-day period ending Monday, February 25 at 7 pm EST. The core Midwest drought region is expected to get about an inch of precipitation. Since this region needs 3 - 9 inches of precipitation to end the drought, this coming week's rain and snow will take them at least 10% towards that goal. Image credit: NOAA/HPC.


Figure 2. The amount of precipitation needed to bring the contiguous U.S. out of long-term drought conditions (raise the long-term Palmer Drought Severity Index, PDSI, above -0.5) shows that the core drought region in the Midwest needs 3 - 9 inches of precipitation to end the drought. Image credit: NOAA/Climate Prediction Center.

Drought-busting rains coming for Georgia and Alabama; flooding now a concern
Heavy rains last week in Alabama and Georgia helped give that region no areas of exceptional drought for the first time since January 10, 2012. Another 3 - 8 inches of rain is expected during the next five days, which will help bust the multi-year drought that has affected the area. Flash flooding will even be a concern, particularly on Tuesday. However, as noted in the latest NOAA seasonal drought outlook, "any recovery will occur very slowly, as it will take time for any increased rainfall to chip away at the large moisture deficits that have accumulated over the course of a multi-year drought."


Figure 3. NOAA's February 21 Seasonal Drought Outlook calls for drought to persist over at least 60% of the U.S. drought area through the end of May, with new areas of drought developing over the Southwest U.S. and Florida. However, significant improvement is expected in the Southeast and Upper Midwest.

Drought expected to continue into the summer
The area of the contiguous U.S. covered by drought remained unchanged this week at 56%, according to the latest U.S. Drought Monitor report. NOAA's February 21 Seasonal Drought Outlook calls for drought to persist over at least 60% of the U.S. drought area through the end of May, with new areas of drought developing over the Southwest U.S. and Florida; significant improvement is expected in the Southeast and Upper Midwest, though. After Monday's storm, the GFS and European (ECMWF) models predict that the jet stream will return to the pattern it was in for the first six weeks of 2013, meaning that precipitation-bearing storms will continue to miss the Midwest through at least the first week of March. Given that this jet stream pattern has been very persistent for many months, it's a good bet that drought will be a huge concern as we enter summer. NOAA's Climate Prediction Center predicts an increased chance of drier than average conditions over southwestern portions of the drought region during the coming three months. In general, droughts are more likely in the Midwest U.S. when warmer than average ocean temperatures prevail in the tropical Atlantic, with cooler than average ocean temperatures in the tropical Eastern Pacific (La Niña-like conditions.) This is what we have had so far in 2013. The equatorial tropical Pacific was about 0.3°C below average (as of February 18). This is similar to the ocean temperatures seen in the spring of 2012, just before the Great Drought of 2012 began.

Drought links:
My post on Lessons from 2012: Droughts, not Hurricanes, are the Greater Danger discussed how drought is our greatest threat from climate change.

Ricky Rood blogs about the Dust Bowl

Jeff Masters

Drought Q

Updated: 8:29 PM GMT on February 21, 2013

Permalink

Arctic sea ice volume now one-fifth its 1979 level

By: JeffMasters, 2:52 AM GMT on February 19, 2013

The stunning loss of Arctic sea ice extent in recent years is undeniable--satellite measurements have conclusively shown that half of the Arctic sea ice went missing in September 2012, compared to the average September during 1979 - 2000. But the extent of ice cover is not the best measure of how the fire raging in Earth's attic is affecting sea ice--the total volume of the ice is more important. But up until 2010, we didn't have the measurements needed to say how the total volume of ice in the Arctic might be changing. Scientists relied on the University of Washington PIOMAS model, which suggested that the loss of Arctic sea ice volume during September might be approaching 75% - 80%. The model results were widely criticized by climate change skeptics as being unrealistic. However, in April 2010, a new satellite called Cryostat-2 was launched, which can measure ice volume by beaming pulses of microwave energy off of the ice. With two years of data to Cryosat-2 data to analyze, the results of the PIOMAS model have now been confirmed by a study published on-line in February 2013 in Geophysical Research Letters. In a University of Washington news release, co-author Axel Schweiger said, "people had argued that 75 to 80 percent ice volume loss was too aggressive. What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid." The U.K.'s Natural Environmental Research Council reported that the team of scientists found that from 2003 to 2012, the volume of Arctic sea ice declined 36% in the autumn and 9% in the winter. The measure of sea ice volume is a good indicator of how the Arctic's most stable, "multi-year" ice is fairing. As the multi-year ice declines, sea ice extent, the total area covered by sea ice, in an "Arctic death spiral". The new study shows that thick, multi-year ice has disappeared in areas north of Greenland, around the Canadian Archipelago, and to the northeast of Svalbard, Norway.


Figure 1. Arctic sea ice volume in thousands of cubic kilometers during the September minimum in 1979 compared to 2012, as estimated by the University of Washington PIOMAS model. Arctic seas ice volume has declined by more than a factor of five. Image credit; Andy Lee Robinson.


Figure 2. The Polar-5 aircraft, carrying the EM instrument that was used to validate Cryosat-2 sea ice thickness measurements, flying over the validation site. Image credit: R. Willatt.

Why care about Arctic sea ice loss?
If you remove an area of sea ice 43% the size of the contiguous U.S. from the ocean, like occurred in September 2012, it is guaranteed to have a significant impact on weather and climate. The extra heat and moisture added to the atmosphere as a result of all that open water over the pole may already be altering jet stream patterns in fall and winter, bringing an increase in extreme weather events. The record sea ice loss in 2012 also contributed to an unprecedented melting event in Greenland. Continued sea ice loss will further increase melting from Greenland, contributing to sea level rise and storm surge damages. Sea ice loss will also continue to crank up the thermostat over Arctic permafrost regions. This will potentially release a significant fraction of the vast amounts of carbon currently locked in the permafrost, further accelerating global warming.

Related Posts
Earth's attic is on fire: Arctic sea ice bottoms out at a new record low (September 2012)
Half of the polar ice cap is missing: Arctic sea ice hits a new record low. September 6, 2012 blog post
Wunderground's Sea Ice page
Arctic Death Spiral Bombshell: CryoSat-2 Confirms Sea Ice Volume Has Collapsed by Joe Romm at climateprogress.org.

Jeff Masters and Angela Fritz

Sea Ice Climate Change

Permalink

U.S. gets unusually boring January weather; Thursday storm to ease Midwest drought

By: JeffMasters, 9:59 PM GMT on February 16, 2013

After an unusually intense period of extreme weather during 2011 and 2012, the U.S. had its quietest month in nearly two years during January 2013, according to NOAA's U.S. Climate Extremes Index (CEI). The index tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought. The CEI during January 2013 was 14%, which was the lowest since the 12% value during February 2011. On average, about 20% of the contiguous U.S. experiences top-10% extreme weather as defined by the CEI. In 2012, just two months (October and February) had below-average CEI, so the weather of January 2013 was a welcome relief from our recent "new normal" of increased extreme weather. Of course, the month wasn't completely without notable weather--the tornado outbreak of January 29 - 30 generated 57 tornadoes, the second largest January tornado outbreak on record. January 2013 ranked as the 39th warmest January since 1895, said NOAA's National Climatic Data Center (NCDC) in their latest State of the Climate report. Utah and Nevada had a top-ten coldest January; no states had a top-ten warmest January. The January warmth was enough to make the 12-month period ending in January 2013 the warmest such period for the contiguous U.S., with every state being warmer than average. Sixteen states, across the central U.S. and Northeast, were record warm, and 27 additional states were top ten warm.


Figure 1. Historical temperature ranking for the U.S. for January 2013. Utah and Nevada had a top-ten coldest January, and no states had a top-ten warmest January. Image credit: National Climatic Data Center (NCDC).

Drought conditions improve slightly; wetter weather on the way to Midwest drought region
January 2013 had slightly above-average precipitation over the contiguous U.S., but there were notable wet and dry extremes. Louisiana had its wettest January on record, and Michigan, Virginia, Tennessee, and Mississippi all had top-ten wettest January weather. Florida, California, and Connecticut all had top-ten driest January weather. Heavy rains in Alabama and Georgia helped give that region no areas of exceptional drought for the first time since January 10, 2012. However, the core of the drought area over the Midwest U.S. shrank only slightly, with the area of the contiguous U.S. experiencing moderate-to-exceptional drought going from 61% on January 1 to 56% on February 12. The U.S. Seasonal Drought Outlook, issued February 7, calls for new areas of drought to develop over Florida, Texas, and California. However, some improvement in drought conditions is expected over about 40% of the drought region by April 30. The latest forecasts from the GFS and European (ECMWF) model show a modest shift in the jet stream pattern during the remainder of February, which may allow more moisture-bearing low pressure systems to pass through the main portion of the Midwest drought region. One storm for sure will arrive on Thursday, and many areas of the drought region should enjoy their their wettest day in months.


Figure 2. Drought conditions as of February 12, 2013, showed that 56% of the contiguous U.S. was in moderate or greater drought. Image credit: U.S. Drought Monitor.


Figure 3. Predicted precipitation for the 7-day period ending Saturday, February 23 at 7 pm EST. Almost the entire nation is expected to get precipitation, including the core of the drought region. Image credit: NOAA/HPC.

Forward on Climate rally on February 17th in Washington, D.C. 
On Sunday, February 17, at noon EST, what is expected to be the largest climate rally in history will take place in Washington D.C. The rally is a project of the Sierra Club, 350.org, and the Hip Hop Caucus. The organizers mustered 15,000 protesters last year in D.C. to protest the potential approval of the Keystone XL Pipeline (meant to bring oil from Canada's tar sands into the U.S.) Protesting the potential approval of the pipeline will be a major focus of Sunday's rally, as well. More broadly, the rally aims to put pressure on President Obama to make good on the promises he made during Tuesday's State of the Union Address:

"But for the sake of our children and our future, we must do more to combat climate change. Yes, it’s true that no single event makes a trend. But the fact is, the 12 hottest years on record have all come in the last 15. Heat waves, droughts, wildfires, floods – all are now more frequent and more intense. We can choose to believe that Superstorm Sandy, and the most severe drought in decades, and the worst wildfires some states have ever seen were all just a freak coincidence. Or we can choose to believe in the overwhelming judgment of science – and act before it’s too late….But if Congress won’t act soon to protect future generations, I will."

It's about time that the President began talking about the reality of our changing climate, and the need to pursue aggressive actions to combat human-caused climate change. January 2013 was a welcome relief from the intense stretch of extreme weather our nation has suffered over the past two years. But the extreme weather of 2011 - 2012 is going to be more typical of our "new normal" of weather during the coming decades. Earth's climate is warming, and the overwhelming majority of climate scientists agree that human activity is the main cause. Extreme weather events are increasing in response to the warming climate. People can take cost-effective actions to limit the damage, and our lawmakers are going to come under increasing pressure from grass-roots efforts like the Forward on Climate rally to act to slow down climate change.

I'll have a new post on Tuesday.

Jeff Masters

Climate Summaries Drought

Updated: 4:47 PM GMT on February 17, 2013

Permalink

Meteor over Russia causes shock waves that injure at least 950

By: JeffMasters, 3:12 PM GMT on February 15, 2013

Allthough this blog is mostly about meteorology--the science of the weather--it's worth commenting on the incredible meteor that streaked through the skies of Russia over the Ural Mountains near 9:20 am local time on Friday. The shock waves from the meteor blew out windows, collapsed the walls and ceiling of a zinc factory, and injured over 950 people. According to astronomer Margaret Campbell-Brown of the University of Western Ontario, in an interview with nature.com, today's meteor was 15 meters in diameter and weighed 40 tons, making it the largest one to affect Earth since the 1908 Tunguska meteor in Siberia. The number of injuries reported from today's event is unprecedented in modern human history for a meteor. The meteor appeared less than a day before asteroid 2012 DA14 will make the closest recorded pass of an asteroid to Earth since sky surveys began in the 1990s--about 17,150 miles, which is closer than the orbit of the GOES weather satellites. According to NASA (as posted on spaceweather.com), "the trajectory of the Russian meteorite was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. Information is still being collected about the Russian meteorite and analysis is preliminary at this point. In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14's trajectory is in the opposite direction, from south to north." The odds of the largest meteor strike in 100 years occurring on the same day as the closest asteroid approach in 15 years are about 1 in 200 million, assuming these events are not correlated--truly a cosmic coincidence! The root word meteor comes from the Greek meteōros, meaning "high in the air", and the science of meteorology is the study of weather (notably hydrometeors--things like rain and snow and hailstones that fall from the sky.)


Figure 1. In this photo provided by Chelyabinsk.ru, a meteor contrail is seen over Chelyabinsk, Russia on Friday, Feb. 15, 2013. The meteor streaked across the sky of Russia’s Ural Mountains on Friday morning, causing sharp explosions and reportedly injuring at least 950 people, including many hurt by broken glass. (AP Photo/ Chelyabinsk.ru)


Figure 2. In this photo provided by Chelyabinsk.ru, municipal workers repair damaged electric power circuit outside a zinc factory building with about 600 square meters (6000 square feet) of a roof collapsed after a meteorite exploded over in Chelyabinsk region on Friday, Feb. 15, 2013. (AP Photo/ Oleg Kargapolov, Chelyabinsk.ru)


Figure 3. A hole in Chebarkul Lake, Russia claimed to be from meteorite debris from today's meteor. Photo by Chebarkul town head Andrey Orlov.


Video 1. A Russian dashboard camera caught this incredible video of the February 15, 2013 fireball over Russia. In case you were wondering why there are so many Russian dash board camera videos on the Internet, geek.com explains that it's a combination of the bad weather and corruption in the country.


Video 2. The massive shockwave from the the blast hits at about 0:30 into this video, followed by lots of sonic booms. Thanks go to skyepony for posting this in my blog comments.

Links
engadget.com has a compilation of five impressive videos of the event.
rt.news has an excellent collection of still images and videos.

NASA TV will begin streaming live coverage of the fly-by of asteroid 2012 DA14 at 2 pm EST (19:00 UTC.) The asteroid's closest approach to Earth will be at 2:25 pm EST Friday. The half-hour broadcast from NASA's Jet Propulsion Laboratory in Pasadena, CA, will incorporate real-time animation to show the location of the asteroid in relation to Earth, along with live or near real-time views of the asteroid from observatories in Australia, weather permitting.

Jeff Masters

Atmospheric Phenomena

Updated: 6:04 PM GMT on February 15, 2013

Permalink

NHC upgrades Sandy to a Cat 3 in reanalysis, affirms changes needed for warnings

By: JeffMasters, 4:01 PM GMT on February 13, 2013

The National Hurricane Center released their final analysis of Hurricane Sandy this week. At 157 pages and 14 Mb, it's by far the largest tropical cyclone report NHC has ever released (previous record: 55 pages from Hurricane Ike of 2008.) NHC upgraded Sandy to a Category 3 hurricane in post-analysis. Data from the Hurricane Hunters showed that Sandy had 115 mph sustained winds at landfall in Cuba, making Sandy the second major hurricane of the 2012 season (Michael was the other.) NHC's report reaffirmed that Sandy was not a hurricane when it made landfall in New Jersey, having transitioned to a post-tropical cyclone when it was 2.5 hours and 50 miles away from landfall. Sandy officially made landfall in New Jersey as a post-tropical cyclone with sustained 80 mph winds and a central pressure of 945 mb. However, Sandy did bring hurricane force sustained winds to the coast before transitioning to a post-tropical cyclone. Great Gull Island, New York, between Long Island and Fishers Island, measured a 1-min mean wind of 75 mph at an elevation of 18 m (59') at 4:35 pm EDT on 29 October, about 25 minutes before Sandy lost its status as a hurricane. NHC noted: This observation suggests that sustained hurricane-force winds likely occurred onshore over a limited area while Sandy was still a hurricane.


Figure 1. Hurricane Sandy at 10:10 am EDT October 28, 2012. Image credit: NASA/GSFC.

Sandy was responsible for 72 direct deaths in the U.S., the second highest toll from a U.S. hurricane since Hurricane Agnes of 1972 (Hurricane Katrina of 2005 was the highest, with at least 1500 direct deaths.) Sandy's storm surge was responsible for most of the U.S. deaths--41 of the 72 fatalities (57%). Falling trees during the storm killed twenty people, a rather high number that again highlights that hazard in the northeastern and mid-Atlantic states, even in locations experiencing winds of less than hurricane force. At least 87 deaths, an even greater number than for direct deaths, were indirectly associated with Sandy or its remnants in the United States. About 50 of these deaths were the result of extended power outages during cold weather, which led to deaths from hypothermia, falls in the dark by senior citizens, or carbon monoxide poisoning from improperly placed generators or cooking devices.

Sandy by the numbers: some statistics from NHC's final report on Sandy:

Death toll: 147 (72 in the U.S., 54 in Haiti, 11 in Cuba)

U.S. Damage: $50 billion, second costliest hurricane of all-time

Cuban Damage: $2 billion, fourth costliest hurricane of all-time

Haitian Damage: $0.75 billion, costliest hurricane of all-time

Homes damages/destroyed: 945,000 (650,000 in U.S.)

Power outages: 8.5 million U.S. customers, 2nd most for a natural disaster behind the 1993 blizzard (10 million)

Maximum sustained winds measured: 93 mph at Cabo Lucrecia, Cuba

Maximum U.S. sustained winds measured: 75 mph at Great Gull Island, New York

Peak U.S. wind gust: 95 mph at Eaton's Neck, Long Island, NY (24 m elevation)

Maximum U.S. storm surge: 12.65', King's Point, NY, west end of Long Island Sound

Maximum U.S. Storm Tide (measured above MLLW): 14.58', Bergen Point, NJ

Maximum Storm Tide at The Battery in New York City: 14.06'. This is 4.36 ft higher than the previous record set in December 1992, and 4.55 ft higher than in Tropical Storm Irene in 2011.

Maximum significant wave height: 33.1' at the buoy east of Cape Hatteras, NC (2nd highest: 32.5' at the Entrance to New York Harbor)

Maximum rainfall: 28.09", Mill Bank, Jamaica

Maximum U.S. rainfall: 12.83", Bellevue, MD

Maximum snowfall: 36", Richwood, WV and Wolf Laurel Mountain, NC

Minimum pressure: 945.5 mb, Atlantic City, NJ at 7:24 pm EST, October 29, 2012. This is the lowest pressure measured in the U.S., at any location north of Cape Hatteras, NC (previous record: 946 mb in the 1938 hurricane on Long Island, NY)

Destructive potential of storm surge: 5.8 on a scale of 0 to 6, highest of any hurricane observed since 1969. Previous record: 5.6 on a scale of 0 to 6, set during Hurricane Isabel of 2003.

Maximum diameter of tropical storm-force winds: 1000 miles, highest for any Atlantic tropical cyclone on record, going back to 1988.

Diameter of ocean with 12' seas at landfall: 1500 miles


Figure 2. Snowfall from Superstorm Sandy hit 36" at locations in West Virginia and North Carolina.
Image credit: NOAA/HPC.

Questions on NHC's handling of warnings for Sandy
In the Sandy report, NHC documents that their forecasts of Sandy's track, intensity, and storm surge were all excellent, largely beating the average error margin for forecasts for tropical cyclones made during the previous five years. However, NHC has been criticized for electing not to issue hurricane warnings in advance of Hurricane Sandy for the U.S. Sandy was expected to transition to a non-tropical system before landfall, and NHC opted days in advance to issue high wind warnings and not hurricane warnings for the U.S. It is quite possible that NHC's decision not to put up hurricane warnings cost lives, since the public pays far more attention to hurricane warnings than any other type of wind warning (except tornado warnings.) In the Sandy report, NHC argues that "Intentionally misrepresenting Sandy as a hurricane would have severely damaged the credibility of the NWS and undermined its ability to serve the public for years to come." Another option to properly call Sandy post-tropical but put up hurricane warnings for the coast was also considered, but "a procedure for disseminating post-tropical advisories with tropical warnings had never been developed, tested, or publicized, and the NWS feared that hurriedly crafting and implementing untested procedures could easily break automated vendor software and disrupt the flow of information to users at a critical moment." The report acknowledges that due to the unique situation posed by Hurricane Sandy, a change to the hurricane warning definition is needed. They propose: The hurricane warning definition would be broadened to apply to systems after their tropical cyclone stage has ended, thus allowing hurricane or tropical storm watches and warnings to remain in effect for post-tropical cyclones. In addition, the NWS would ensure the continuity of service in any situation by allowing the NHC to issue advisories through the post-tropical cyclone stage as long as the system poses a significant threat to life and property. A second proposal: "set a target date of 2015 for NOAA to implement explicit storm surge watches and warnings, a goal NOAA has been working toward for several years. Multiple studies have shown significant confusion on the part of the public regarding their storm surge risk, and highlighted the need for improved communication of this hazard. With the implementation of a storm surge warning, the NWS will warn explicitly for the phenomenon that presents the greatest weather-related threat for a massive loss of life in a single day." Both of these changes are ones I hope get adopted as soon as practical, as the warning information given to the public during Sandy could have been much better, potentially saving lives and property.

Spectacular NOVA show tonight: Earth From Space
The PBS NOVA series is airing a two hour special tonight (Wednesday), called "Earth From Space", a spectacular new space-based vision of our planet. The promo on the website advertises: Produced in extensive consultation with NASA scientists, NOVA takes data from earth-observing satellites and transforms it into dazzling visual sequences, each one exposing the intricate and surprising web of forces that sustains life on earth. Viewers witness how dust blown from the Sahara fertilizes the Amazon; how a vast submarine "waterfall" off Antarctica helps drive ocean currents around the world; and how the Sun's heating up of the southern Atlantic gives birth to a colossally powerful hurricane. From the microscopic world of water molecules vaporizing over the ocean to the magnetic field that is bigger than Earth itself, the show reveals the astonishing beauty and complexity of our dynamic planet. It should be a great show!

Jeff Masters

Hurricane

Permalink

First EF-4 tornado of 2013 injures 82 near Hattiesburg, MS

By: JeffMasters, 1:10 AM GMT on February 12, 2013

The strong tornado that swept through Hattiesburg and Oak Grove in Lamar County, Mississippi, on Sunday has been rated an EF-4 with 170 mph winds, making it the first violent EF-4 tornado of 2013. The tornado hit Hattiesburg at 5:12 pm CST February 10, injuring 82 people and causing widespread damage over a 20-mile-long path. Miraculously, there were no deaths.The only other violent EF-4 tornado ever to hit Lamar County occurred on April 24, 1908, according to NWS Jackson.


Figure 1. Oak Grove High School football field near Hattiesburg, MS after Sunday's tornado. Damage was rated EF-4 near the high school, and there was clear evidence of the tornado being multi-vortex over a portion of its path. Image credit: NWS Jackson Facebook page.

The 2013 tornado season is off to an unusually busy start--a pattern we also saw last year. The January 29 - 30, 2013 tornado outbreak now has 56 confirmed tornadoes, including the only EF-3 tornado of the year, which hit Adairsville, GA, on January 30, killing one person. The outbreak is now ranked as the second largest January tornado outbreak since records began in 1950 (the largest: 128 tornadoes on January 21 - 22, 1999 .) NOAA's Storm Prediction Center logged twelve preliminary reports of tornadoes on Sunday, from Mississippi and Alabama. This brings the tally of preliminary tornado reports for the year to 100. On average, we've had just 72 preliminary tornado reports by February 10 during the previous seven years, 2005 - 2011.


Video 1. Hotel worker Rynal Grant caught this impressive video of the February 10, 2013 Hattiesburg, Mississippi tornado.

Portlight receives $125,000 grant for New Jersey relief efforts
On September 14, 2008, the devastation wrought by Hurricane Ike on Texas and Louisiana moved members of the wunderground community to put into action their own impromptu relief effort. From this humble beginning has grown a disaster-relief charity I have been proud to support--Portlight.org. Portlight has stood up to support the needs of thousands of people affected by natural disasters since Hurricane Ike. After Hurricane Sandy, Portlight became a clearinghouse for local, state and federal agencies, including the FEMA Functional Needs Task Force--New Jersey, meeting the needs of people with disabilities. This week, Portlight announced that they had received a grant of $125,000 to continue helping in New Jersey in a big way. Congratulations, Portlight!


Figure 2. Vince Sciacca was in a horrific car accident a few years ago, which put him in a coma for nine months and left him with a severe brain injury. Shortly before Superstorm Sandy struck, and after much struggle, he had finally straightened out his equipment needs. The storm came along and destroyed everything. Portlight's project manager, Steve Major, delivered this power chair to Vince on February 2, and will be working with him to replace other equipment, as well.

Visit the Portlight.org. Portlight.org website to find out more or Portlight blog to learn more. Donations are always welcome!

Jeff Masters

Tornado

Updated: 1:31 AM GMT on February 12, 2013

Permalink

Climate change impact on Nor'easters: An increased storm surge threat

By: JeffMasters, 3:53 PM GMT on February 11, 2013

The historic Nor'easter that buried New England under up to 40" of snow Friday and Saturday was the most intense winter storm event on record for southeastern Maine, and second most for Long Island, Connecticut, eastern Massachusetts, and perhaps Rhode Island, writes wunderground's weather historian Christopher C. Burt. His rating was based upon both snowfall amounts and winds. For Long Island and Connecticut, the Blizzard of 1888 remains unparalleled, whereas for Rhode Island and eastern Massachusetts, the Blizzard of 1978 remains the top event. His rating took into account snowfall and winds, and took into account historical storms going back over 300 years. So, what impact is climate change having upon these great storms?


Figure 1. Is it a hurricane or an extratropical storm? Satellite image of Winter Storm Nemo taken at 3 pm EST Saturday, February 9, 2013 shows a very hurricane-like storm. The storm had undergone a process known as "occlusion", which trapped a shallow area of warm air near the center. These "warm air seclusions" are not uncommon in intense wintertime extratropical storms, and Nemo was not very hurricane-like in structure, despite the appearance of this satellite image. Image credit: NASA/GSFC.

Climate change impact on Nor'easters: an increased storm surge threat
We should not be surprised to see climate change causing significant changes in the frequency and intensity of Nor'easters, since the atmosphere is undergoing great changes in its circulation patterns and moisture content that will affect all storms. As I wrote in my post, The future of intense winter storms, climate models predict that intense winter storms will become more common globally, and will shift closer to the poles. However, in the Atlantic, intense Nor'easters affecting the U.S. are not predicted to increase in number (but several studies predict an increase in intense winter storms for Northwest Europe.) The number of intense Nor'easters affecting the Northeast U.S. has not increased in recent decades, according to several studies. This analysis is supported by the fact that wintertime wave heights recorded during the period 1975 - 2005 by the three buoys along the central U.S. Atlantic coast showed little change (Komar and Allan, 2008). The damage potential from the storm surges associated with Nor'easters and hurricanes in New England is steadily increasing, though, due to global warming.


Figure 2. Surf from the infamous blizzard of 1978 pounds the coast of Scituate, Massachusetts on February 9, 1978. The storm brought Boston's highest water level on record. Hurricane Sandy brought a higher storm surge to Boston, but the storm hit when the tide was going out, and thus did not set a record high water mark. Image credit: NOAA Photo Library.

An increased storm surge threat for Boston
Of the top ten water levels measured in Boston Harbor since 1921 (all due to Nor'easters), all but one of these events occurred during the the second half of that 92-year period. That's due to rising sea levels. The official top ten storm tides since 1921 at the Boston tide gauge, relative to high tide (Mean Higher High Water, MHHW):

1. 4.82' - February 7, 1978 (Blizzard of 1978)
2. 3.92' - January 2, 1987
3. 3.86' - October 30, 1991 (Perfect Storm)
4. 3.76' - January 28, 1979
5. 3.75' - December 12, 1992
6. 3.70' - December 12, 1959
7. 3.62' - February 2, 1972
8. 3.52' - April 4, 2007
9. 3.51' - May 5, 2005
10. 3.43' - December 12, 2010

Sea level at the Boston tide gauge has risen about a foot (.25 meters) since records began in 1921. Most of that rise is due to the expansion of ocean waters due to global warming, plus increased melting from glaciers and icecaps. According to an excellent analysis by Andrew Freedman of Climate Central, continued sea level rise in Boston will increase the odds of a 1-in-100 year coastal storm surge flood by a factor of 2.5 by the year 2030. Even given the low end of sea level rise scenarios, and without assuming any changes in storms, 1-in-10-year coastal flooding events in the Northeast could triple by 2100, occurring roughly once every 3 years, simply in response to higher sea levels (Tebaldi et al. 2012). Nemo arrives just days after a report the nonprofit Boston Harbor Alliance warned of the region’s growing vulnerability to such storm surge events. The report found that coastal flooding of 5 feet above the current average high tide--a 1-in-100 year flood--would inundate 6.6 percent of the city of Boston. At 7.5 feet above the current average high tide, more than 30 percent of Boston could be flooded, the study found. Boston has gotten lucky two storms in row now--both Hurricane Sandy (storm surge of 4.57') and Winter Storm Nemo (storm surge of 4.21') brought their peak surge near low tide, so the water level during these storms did not make the top-ten list, even though these were two of the four highest storm surges ever measured in Boston. Mr. Burt comments, "it is a bit unsettling that two of the most significant storms in the past 300 years to strike the northeastern quadrant of the U.S. have occurred within just four months from one another." Rising sea levels are already making coastal living at low elevations an increasingly precarious proposition in the Northeast. If Sandy and Nemo are harbingers of a new era of stronger storms for the Northeast U.S., the double-whammy combination of bigger storm surges riding in on higher sea levels will make abandoning higher-risk portions of the coast a necessity.


Figure 3. Severe beach erosion on Plum Island, MA, observed on February 10, 2013, in the wake of Winter Storm Nemo. It was lucky the peak storm surge hit near low tide, or else the coastal damage would have been far more severe. Image credit: Mike Seidel.


Figure 4. Sea level at the Boston tide gauge from 1921 - 2011 shows 2.77 mm/year of rise, or .98 feet (.25 meters) in 91 years. Image credit: NOAA Tides and Currents.

Links and references
My blog post, The future of intense winter storms

My blog post, Heavy snowfall in a warming world

Andrew Freedman of Climate Central's post, Blizzard of 2013 Brings Another Threat: Coastal Flooding

Joe Romm of climateprogress.org has a post, Climate Change and Winter Storm Nemo that has an excellent discussion of how climate change has modified the environment within which storms form, increasing their potential to cause heavy precipitation events.

Komar, P.D. and J.C. Allan, 2008: Increasing hurricane-generated wave heights along the U.S. East coast and their climate controls. Journal of Coastal Research, 24(2), 479-488.

Tebaldi, C., B.H. Strauss, and C.E. Zervas, 2012: Modelling sea level rise impacts on storm surges along US coasts. Environmental Research Letters, 7, 014032

Tom Niziol has an interesting post showing why Connecticut got so much snow from the storm: Northeast snow storm--the pivot point

Lee Grenci discusses how the two winter systems that combined to create the mighty snowstorm didn't really merge, but instead rotated around each other: Looming Snowstorm and the Fujiwhara.

Jeff Masters

Winter Weather Climate Change

Updated: 6:36 PM GMT on February 11, 2013

Permalink

Snow measured in feet, not inches: historic Nor'easter pounds New England

By: JeffMasters, 4:50 PM GMT on February 09, 2013

A historic Nor'easter roared through New England overnight, bringing snowfall measured in feet, not inches, hurricane-force wind gusts, and serious coastal flooding. The snow was heaviest in coastal Connecticut, where snowfall rates of 6"/hours were recorded, and an astonishing 40" piled up in Hamden. An all-time snowfall record was set in Portland, Maine, where 31.9" fell, and numerous cities in the Northeast recorded top-ten snowfall amounts, including Hartford, CT (2nd all-time with 22.3"); Worchester, MA (3rd all-time, with 28"); Providence, RI (8th all-time, with 17"); Concord, NH (2nd all time, with 24"), and Boston, MA (6th all-time, with 21.8.") NOAA's latest Storm Summary has a full list of snowfall amounts.

Here are the seven snowstorms of greater than 20" since 1936 for Logan Airport (figures from today's storm are not final yet):

1. February 17-18, 2003 27.5"
2. February 6-7, 1978 27.1"
3. February 24-27, 1969 26.3"
4. March 31-April 1, 1997 25.4"
5. January 22-23, 2005 22.5"
6. February 8-9, 2013 21.8"
7. January 20-21, 1978 21.4"


Figure 1. Not driving anywhere today! Snow buries cars in New Haven, CT at the Premier Hotel & Suites on Long Wharf on February 9, 2013. Image credit: wunderphotographer phototex.

The great storm, dubbed "Nemo", bombed out to a central pressure of 971 mb at 7 am EST Saturday, February 9. This is the type of central pressure one sees in Category 1 hurricanes, and Nemo generated numerous hurricane-force wind gusts along the coast, including a 76 mph gust at Boston's Logan Airport. Significant wave heights of 30' were measured in Massachusetts Bay, and 35.4'at the Cape Ann Buoy 44098, off the east coast of Massachusetts. Here are the hurricane-force wind gusts (in mph) measured so far in Nemo:

Connecticut:
WESTPORT 82
PORTLAND 81

Massachusetts:
CUTTYHUNK 83
HYANNIS 77
BOSTON LOGAN AIRPORT 76
BEDFORD 75
BUZZARDS BAY 74
MARSTONS MILL 74

New Hampshire:
MOUNT WASHINGTON 81

Maine:
BROOKLIN 75

New York:
PLUM ISLAND 75


Figure 2. Satellite image of Winter Storm Nemo taken at 4:31 pm EST Friday, February 8, 2013. Image credit: NASA/GSFC.

Serious coastal flooding hits Massachusetts
The high winds from the storm drove a damaging storm surge into the coast of Eastern Massachusetts Friday night and Saturday morning. Hardest hit was the coast of Cape Cod Bay southeast of Boston, where major flooding forced residents of low-lying areas to evacuate. A storm surge in excess of four feet inundated roads, damaged coastal buildings, and caused severe beach erosion. Officially, the surge peaked at 4.21' in Boston early Saturday morning. Unofficially, this is fourth greatest storm surge measured in Boston since record keeping began in 1921. Fortunately, the surge hit as low tide was approaching, and the "storm tide"--how how the water gets above the high tide mark, due to the combination of the storm surge and the tide--only reached 2.86' above high tide (MHHW, Mean Higher High Water) in Boston. Nemo's storm tide did not make the top-ten list of high water levels in Boston.

Top unofficial top-five storm surge (not storm tide) events in Boston's history, given as height above normal tide:

4.88' on October 30, 1991 during the "Perfect Storm" Halloween Nor'easter
4.57' on October 29, 2012 during Hurricane Sandy
4.34' on February 6, 1978, during the Blizzard of 1978
4.21' on February 9, 2013, during Winter Storm Nemo
3.69' on February 14, 1940, during the Valentine's Day Nor'easter of 1940

The 1938 hurricane and March 18, 1956 Nor'easter had storm surges less than two feet at Boston. The Christmas Night Storm of 1909 caused severe coastal flooding, but tide gauge records in Boston don't begin until 1921.

The official top ten storm tides since 1921 at the Boston tide gauge, relative to MHHW, are:

1. 4.82' - February 7, 1978 (Blizzard of 1978)
2. 3.92' - January 2, 1987
3. 3.86' - October 30, 1991 (Perfect Storm)
4. 3.76' - January 28, 1979
5. 3.75' - December 12, 1992

Links:
NASA has a nice satellite animation of the storm, spanning a day.

Our news page:
http://www.wunderground.com/news/

Our winter Storm page:
http://www.wunderground.com/winter-storm/nemo-2013.asp

A few impressive 24-hour videos from wunderground webcams:

Bellingham, MA:
http://www.wunderground.com/webcams/steved281/1/video.html?month=02&year=2013&filename=current.mp4

Woonsocket, RI
http://www.wunderground.com/webcams/Traj/1/video.html?month=02&year=2013&filename=current.mp4

Hartford, CT
http://www.wunderground.com/webcams/N1PSJ/1/video.html?month=02&year=2013&filename=current.mp4

Lexington, MA
http://www.wunderground.com/webcams/zach34298/1/video.html?month=02&year=2013&filename=current.mp4

Jeff Masters

Winter Weather

Updated: 8:48 PM GMT on February 09, 2013

Permalink

Snows begin in Northeast U.S. as historic Nor'easter strengthens

By: JeffMasters, 3:17 PM GMT on February 08, 2013

Snow has begun falling from New York City to Massachusetts, where blizzard warnings are flying in anticipation of the arrival of one of the most severe and dangerous Nor'easters in U.S. history. The great storm, dubbed "Nemo", has just emerged into the waters off the coast of Virginia, and is predicted to "bomb" to a central pressure of 975 - 980 mb by Saturday afternoon. Cold, Arctic air spilling southwards behind a strong 1038 mb high over Canada will collide with warm, moist air over the Atlantic, where ocean temperatures are unusually warm--about 5°F warmer than average over a large swath from New Jersey to Nantucket, Massachusetts. The contrast between the cold and warm air will help intensify the storm, and the unusually warm waters will pump large quantities of moisture into the air, which will be capable of feeding record-breaking snows over New England. The latest NWS forecast for Boston calls for 22 - 30" of snow by Saturday morning, with additional snows though Saturday afternoon. Since Boston's all-time heaviest snow storm is 27.5" (February 17-18, 2003), Winter Storm Nemo has a chance of exceeding that. According to NWS, here are the top snowstorms since 1936 for Logan Airport:

1. February 17-18, 2003 27.5"
2. February 6-7, 1978 27.1"
3. February 24-27, 1969 26.3"
4. March 31-April 1, 1997 25.4"
5. January 22-24, 1945 22.8"
6. January 22-23, 2005 22.5"
7. January 20-21, 1978 21.4"
8. March 3-5, 1960 19.8"
9. February 16-17, 1958 19.4"
10. February 8-10, 1994 18.7"
11. January 7-8, 1996 18.2"
11. December 20-22, 1975 18.2"
11. December 26-27, 2010 18.2"


The weight of all that heavy snow on rooftops will create the danger of roof collapses. In addition to the heavy snow, the storm will bring coastal wind gusts over hurricane force, and moderate to major coastal flooding. During the peak of the storm, Friday night into Saturday morning, snowfall rates of 2 - 3" per hour can be expected. These intense bursts of snow may be accompanied by lightning and thunder. The cites of Hartford, Providence, and Portland are all likely to get more than a foot of snow, and two feet of snow will probably fall along a swath from South Central Connecticut to Southwest Maine, with isolated amounts of 3'. Ferocious sustained winds near 50 mph will occur at the coast, with wind gusts in excess of hurricane force--74 mph. The combination of heavy snow and high winds will make travel extremely dangerous or impossible, with near-zero visibility in white-out conditions. The snow and high winds are likely to cause many power outages.


Figure 1. Predicted snowfall for Winter Storm Nemo from Friday's 00Z run of the European (ECMWF) model. The highest snowfall amounts (> 24") are predicted for Long Island, Southern Connecticut, and Eastern Massachusetts, including Boston. This forecast assumes that the ratio between liquid water equivalent and snow depth will be 10:1. In some areas away from the coast, this ratio may be closer to 15:1, leading to snow amounts near 36".


Figure 2. Predicted wind speeds in knots at 7 am EST Saturday, February 9, 2013, from the 00Z February 8, 2013 run of the European (ECMWF) model. The model is predicting sustained winds of 50 knots (57.5 mph) will be just offshore of Cape Cod and Nantucket Island, Massachusetts. Multiply by 1.15 to convert knots to mph.

Serious coastal flooding expected in Massachusetts
The high winds from the storm will drive a damaging storm surge of 2 - 4' along the coast of Eastern Massachusetts Friday night and Saturday morning. High tide Friday night will occur between 9:30 - 10 pm EST, and minor to moderate coastal flooding is expected along east and north-facing shores, when the storm surge of 2 - 3' rides in on top of the tide. Battering waves of 8 - 17' will hit the coast south of Boston in Cape Cod Bay, causing severe beach erosion. Of greater concern is the flooding that will occur during the Saturday morning high tide cycle, as that is the time of the new moon, which will bring the highest tide of the month. The ocean's height near Boston varies naturally by about ten feet between low tide and high tide, so it matters greatly when the storm surge arrives, relative to the tidal cycle. Thus we speak of the "storm tide"--how high the water gets above the high tide mark, due to the combination of the storm surge and the tide. During Hurricane Sandy, on October 29, 2012, a potentially very damaging storm surge of 4.57' hit Boston, but arrived near low tide, so the water level during the peak surge did not rise above the normal high tide mark. Fortunately, it appears that the peak storm surge from Nemo will arrive at the time of low tide early Saturday morning, and the surge will have fallen about a foot by the time the high tide arrives near 10 am EST Saturday. As of 9am EST on February 8, 2013, the latest storm surge forecast from the GFS model was calling for a storm tide of about 3.4' above high tide (MHHW, Mean Higher High Water) in Boston on Saturday morning. This would cause minor to moderate flooding in the city, and would be approximately the 10th highest water level on record. The official top 5 storm tides since 1921 at the Boston tide gauge, relative to MHHW, are:

1. 4.82' - February 7, 1978 (Blizzard of 1978)
2. 3.92' - January 2, 1987
3. 3.86' - October 30, 1991 (Perfect Storm)
4. 3.76' - January 28, 1979
5. 3.75' - December 12, 1992

More serious flooding is expected in Cape Cod Bay to the southeast of Boston, where the northeast winds from the storm will pile up a higher storm surge. A storm surge of 3 - 4' is predicted from Scituate to Sandwich Harbor Saturday morning. The surge will be accompanied by battering waves 18 - 26' feet high, and major flooding and significant coastal erosion is expected. Major coastal flooding is also expected on the east end of Nantucket Island.

Severe beach erosion is also expected along the north and northeast facing shores of Long Island, NY, where a storm surge of 3 - 5' will combine with 4 - 8' breaking waves. Minor to moderate coastal flooding is expected along western Long Island Sound. New York City is expecting a 2 - 4' storm surge, which will cause mostly minor flooding, with a few areas of moderate flooding.


Figure 3. Coastal flooding hazards during the high tide cycle on Saturday morning, February 9, 2013, as predicted at 5 am EDT Friday, February 8, 2013, by the NWS Boston.

Links:

Our news page
http://www.wunderground.com/news/

Our winter Storm page:
http://www.wunderground.com/winter-storm/nemo-2013.asp

Jeff Masters

Winter Weather

Updated: 5:01 PM GMT on February 08, 2013

Permalink

Historic Nor'easter poised to slam Boston and the Northeast U.S.

By: JeffMasters, 3:43 PM GMT on February 07, 2013

A potentially historic Nor'easter is brewing for the Northeast U.S., where blizzard watches are up for much of eastern Massachusetts, Rhode Island, and Connecticut. The storm, dubbed "Nemo" by the Weather Channel, is expected to bring heavy snows of 1 - 2 feet, coastal wind gusts over hurricane force, and moderate to major coastal flooding. During the peak of the storm, Friday night into Saturday morning, snowfall rates of 2 - 3" per hour can be expected. These intense bursts of snow may be accompanied by lightning and thunder. The cites of Boston, Hartford, Providence, Portland, and Burlington are all likely to get more than a foot of snow, and two feet of snow will probably fall along a swath from the western suburbs of Boston to Southwest Maine. With the Nor'easter generating these heavy snows expected to bomb out with a central pressure of 972 - 976 mb, the rapid flow of air around this low pressure center will generate ferocious sustained winds near 50 mph at the coast, with wind gusts in excess of hurricane force--74 mph. The combination of heavy snow and high winds will make travel extremely dangerous or impossible, with near-zero visibility in white-out conditions. Total snowfall from the storm is likely to rank in the top ten for Boston since weather observations began at Logan Airport in 1936. According to NWS, here are the top snowstorms since 1936 for Logan Airport:

1. February 17-18, 2003 27.5"
2. February 6-7, 1978 27.1"
3. February 24-27, 1969 26.3"
4. March 31-April 1, 1997 25.4"
5. January 22-24, 1945 22.8"
6. January 22-23, 2005 22.5"
7. January 20-21, 1978 21.4"
8. March 3-5, 1960 19.8"
9. February 16-17, 1958 19.4"
10. February 8-10, 1994 18.7"
11. January 7-8, 1996 18.2"
11. December 20-22, 1975 18.2"
11. December 26-27, 2010 18.2"


Figure 1. Predicted wind speeds in knots at 7 am EST Saturday, February 9, 2013, from the 00Z February 7, 2013 run of the European (ECMWF) model. The model is predicting sustained winds of 50 knots (57.5 mph) will affect Cape Cod and Nantucket Island, Massachusetts. Multiply by 1.15 to convert knots to mph.

Serious coastal flooding expected in Massachusetts
The high winds from the storm will drive a damaging storm surge of 2 - 4' along the coast of Eastern Massachusetts Friday night and Saturday morning. Of particular concern is the flooding that will occur during the Saturday morning high tide cycle, as that is the time of the new moon, which will bring the highest tide of the month. The ocean's height in Boston varies naturally by about ten feet between low tide and high tide, so it matters greatly when the storm surge arrives, relative to the tidal cycle. Thus we speak of the "storm tide"--how how the water gets above the high tide mark, due to the combination of the storm surge and the tide. During Hurricane Sandy, on October 29, 2012, a potentially very damaging storm surge of 4.57' hit Boston, but arrived near low tide, so the water level during the peak surge did not rise above the normal high tide mark. As of noon EST on February 7, 2013, the latest storm surge forecast from the GFS model is calling for a storm tide of about 3.4' above high tide (MHHW, Mean Higher High Water) on Saturday morning, which would cause only minor flooding in Boston. This would be the 10th highest water level on record in Boston since tide gauge records began in 1921. According to former NHC storm surge expert Mike Lowry, who now works for TWC, the official top 5 storm tides at the Boston tide gauge, relative to MHHW, are:

1. 4.82' - February 7, 1978 (Blizzard of 1978)
2. 3.92' - January 2, 1987
3. 3.86' - October 30, 1991 (Perfect Storm)
4. 3.76' - January 28, 1979
5. 3.75' - December 12, 1992

More serious flooding is expected in Cape Cod Bay to the southeast of Boston, where the northeast winds from the storm will pile up a higher storm surge. A storm surge of 3 - 4' is predicted from Scituate to Sandwich Harbor Saturday morning. The surge will be accompanied by battering waves 20' feet high, and major flooding and coastal erosion is expected. Major coastal flooding is also expected on the east end of Nantucket Island.


Figure 2. Coastal flooding hazards during the high tide cycle on Saturday morning, February 9, 2013, as predicted at 12 pm EDT Thursday, February 7, 2013, by the NWS Boston.

Links:

Our news page
http://www.wunderground.com/news/

Our winter Storm page:
http://www.wunderground.com/winter-storm/nemo-2013.asp

Jeff Masters

Winter Weather Nemo

Updated: 7:59 PM GMT on February 07, 2013

Permalink

Lake Michigan and Lake Huron hit all-time low water levels

By: JeffMasters, 1:00 PM GMT on February 06, 2013

During January 2013, water levels on Lake Michigan and Lake Huron fell to their all-time lowest values since record keeping began in 1918, said the U.S. Army Corps of Engineers on Tuesday. The two lakes (which are connected and are hydrologically the same lake) fell to a water level of 576.02'. This is 0.4" below the previous record low of 576.05' set in March 1964. The lakes have dropped 17 inches since January 2012, and are now 29 inches below their long-term average. Lake Superior is about 9" above its all-time low water level, and Lakes Erie and Ontario are just 6" below average (26 - 27" above their all-time lows), so these lakes will not set new low water records in 2013. The latest forecast calls for Lake Superior to drop 2 inches during February, Lake Michigan and Huron to drop 1 inch, Lake Erie to rise 2 inches, and Lake Ontario remain near its current level.


Figure 1. Low water levels at Old Mission Point Lighthouse at Grand Traverse Bay, Lake Michigan, during July 2000. Image credit: NOAA/GLERL.


Why the record lows?
The record-low water levels on Lake Michigan and Lake Huron are due, in part, to dredging operations in their outflow channel, the St. Clair River. The dredging, which stopped in the 1960s, is blamed for a long-term 10 - 16" decrease in water levels. The record low water levels on Lake Michigan and Lake Huron in January occurred despite the fact that precipitation over their watershed was 61% above average during the month. However, precipitation over the past 12 months was only 91% of average, and runoff into the lakes depends upon precipitation over longer than a 1-month period. Furthermore, evaporation over these lakes was much higher than average during January, making the net water supplied to the lakes (runoff into the lakes, plus precipitation over the lakes, minus evaporation from the lakes) only 63% of average. What caused the increased evaporation? Well, very warm water temperatures, for one. According to NOAA's Great Lakes Environmental Research Laboratory (GLERL), water temperatures over Lake Michigan are currently about 2.5°F above average, and are about 1°F above average over Lake Huron. These warm water temperatures are the lingering effects of the extraordinary warmth of 2012, which was the warmest year on record over much of the Great Lakes region. Also increasing the evaporation from the lakes during January was the presence of less ice cover than average, which exposed more open water to the air.


Figure 2. The water level on Lake Huron and Lake Michigan measured during 2012 - 2013 (red line) hit an all-time low during January 2013, beating the previous record set in March 1964. The predicted water levels for February - March call for record lows both months. Image credit: Army Corps of Engineers.

Ice cover declining, water temperatures warming, and precipitation increasing in recent decades
The long-term future of Great Lakes water levels is cloudy, since climate change is expected to bring competing effects. A 2011 paper by scientists at NOAA Great Lakes Environemental Research Laboratory found that lake levels could rise or fall, depending upon the climate change scenario used. On the one hand, precipitation has increased by 12% over Michigan during the past century, and is expected to increase even more in the coming decades. This would tend to increase lake levels. However, lake water temperatures are predicted to increase and ice cover decrease, which would heighten evaporation rates. This would tend to lower lake levels. Ice cover on North America's Great Lakes--Superior, Michigan, Huron, Ontario, and Erie--has declined 71% since 1973, according to a 2012 study published in the Journal of Climate by researchers at NOAA's Great Lakes Environmental Research Laboratory. The loss of ice is due to warming of the lake waters, which could be due to a combination of global warming and natural cycles, the researchers said. Winter air temperatures over the lower Great Lakes increased by about 2.7°F (1.5°C) from 1973 - 2010, and by 4 - 5°F (2.3 - 2.7°C) over the northern Lakes, including Lake Superior. Lake Superior's summer surface water temperature warmed 4.5°F (2.5°C) over the period 1979 - 2006 (Austin and Colman 2007). During the same period, Lake Michigan warmed by about 3.3°F (1.7°C), Lake Huron by 4.3°F (2.4°C), and Lake Erie (which is shallow and loses and gains heat relatively quickly) showed almost no warming. The Army Corps of Engineers is also considering adding speed bumps to the bottom of the St. Clair River to slow down drainage of Lake Huron, which would act to increase water levels in Lake Huron and Lake Michigan.


Figure 3. Average yearly precipitation over the state of Michigan increased by about 12% per century since 1895, according to NOAA's National Climatic Data Center.

References
Austin, J. A., and S. Colman, 2007, "Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback," Geophys. Res. Lett., 34, L06604, doi:10.1029/2006GL029021.

Wang, J., X. Bai, H. Hu, A.H. Clites, M.C. Colton, and B.M. Lofgren, 2012, "Temporal and spatial variability of Great Lakes ice cover, 1973-2010," Journal of Climate 25(4):1318-1329 (DOI:10.1175/2011JCLI4066.1)

Jeff Masters

Drought Climate Change

Updated: 12:21 AM GMT on May 08, 2013

Permalink

QuikSCAT replacement funded; NWS fires former NHC director Proenza

By: JeffMasters, 2:20 PM GMT on February 04, 2013

In November 2009, one of the greatest success stories in the history of satellite meteorology came to an end when the venerable QuikSCAT satellite failed. Launched in 1999, the QuikSCAT satellite became one of the most useful and controversial meteorological satellites ever to orbit the Earth. It carried a scatterometer--a radar instrument that can measure near-surface wind speed and direction over the ocean. Forecasters world-wide came to rely on QuikSCAT wind data to issue timely warnings and make accurate forecasts of tropical and extratropical storms, wave heights, sea ice, aviation weather, iceberg movement, coral bleaching events, and El Niño. Originally expected to last just 2 - 3 years, QuikSCAT made it past ten, a testament to the skill of the engineers that designed the satellite. Last week, though, NASA announced that a new QuikSCAT-like instrument called ISS-RapidScat will be launched in 2014 on a SpaceX Dragon cargo spacecraft, and installed on the International Space Station (ISS.) In a clever reuse of hardware originally built to test parts of NASA's QuikScat satellite, the cost of the new instrument will be much lower than any previous scatterometer launched into orbit.


Figure 1. Artist's rendering of NASA's ISS-RapidScat instrument (inset), which will launch to the International Space Station in 2014 to measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. It will be installed on the end of the station's Columbus laboratory. Image credit: NASA/JPL-Caltech/JSC

Alternatives to QuikSCAT
Three valuable alternatives to QuikSCAT are available, but none are as good as QuikSCAT was. There's the European ASCAT satellite, launched in 2007. Like QuikSCAT, ASCAT can measure global wind speed and direction twice per day. However, ASCAT covers only 60% of the area covered by QuikSCAT, which saw a swath of ocean 1800 km wide. ASCAT sees two parallel swaths 550 km wide, separated by a 720 km gap. I find it frustrating to use ASCAT to monitor tropical storms, since the passes miss the center of circulation of a storm of interest more than half the time. On the plus side, ASCAT has the advantage that the data is not adversely affected by rain, unlike QuikSCAT. The other main alternative is the OSCAT instrument, which was sent into orbit on September 23, 2009, on the ISRO (Indian Space Research Organization) Oceansat-2 satellite. Like QuikSCAT, the OSCAT has a swath 1800 km wide that covers 90% of Earth's area every 24 hours. The winds at the edge of the swath are not as accurate as the ones in the middle. Moderate and heavy rain cause bogus winds that can be up to 45 mph too high. The resolution is not as high--25 km, versus the 12.5 km resolution of QuikSCAT and ASCAT. The third option is the Windsat instrument aboard the Coriolis satellite (launched in 2003), which measures wind speed and wind direction using a different technique. Evaluation of these data at NHC and NOAA's Ocean Prediction Center (OPC) shown the winds to be unreliable in and around tropical storms.


Figure 2. Bill Proenza, directory of the National Hurricane Center from January 2007 - July 2007.

Former NHC director Bill Proenza fired
Former National Hurricane Center director Bill Proenza, 68, was fired from his position as director of the National Weather Service's Southern Region last week. The reason stated for his firing was his unauthorized transfer of $528,000 from a local forecasting account to pay for new radar equipment in 2012. The issue of moving money without authorization in 2012 also landed the director of NWS, Jack Hayes, in trouble, forcing him to resign.

Proenza laudably made a big push in 2007 for a new QuikSCAT satellite, but unfortunately made claims about the usefulness of QuikSCAT for improving hurricane track forecasts that were not supported by scientific research, an error that may have ultimately led to his downfall as NHC director. Proenza lasted only six months as director of NHC, from January - July 2007. While there is evidence that scatterometer data may improve hurricane track forecasts of some computer models, NHC uses many models to make hurricane track forecasts, and some of these models are not helped by scatterometer data. Scatterometer data is extremely valuable for many other aspects of hurricane forecasting, providing early detection of surface circulations in developing tropical depressions, and helping define gale (34 kts) and storm-force (50 kts) wind radii. The information on wind radii from scatterometers is especially important for tropical storms and hurricanes outside the range of aircraft reconnaissance flights conducted in the Atlantic and Eastern Pacific basins, and for the regions where there are no reconnaissance flights (Central Pacific, Western Pacific, and Indian Ocean). Accurate wind radii are critical to the National Hurricane Center (NHC), Central Pacific Hurricane Center (CPHC), and Guam Weather Forecast Office (WFO) watch and warning process, since they affect the size of tropical storm and hurricane watch and warning areas. Between 2003 and 2006, QuikSCAT data were used at NHC 17% of the time to determine the wind radii, 21% of the time for center fixing, and 62% of the time for storm intensity estimates.

References
2007 NOAA QuikSCAT user impact study:

I'll have a new post on Wednesday.

Jeff Masters

Hurricane Politics

Updated: 3:02 PM GMT on February 04, 2013

Permalink

Wild weather week ends; Mississippi River rises out of danger zone

By: JeffMasters, 2:44 PM GMT on February 01, 2013

One of the most unusual weeks of January weather in U.S. history has drawn to a close, and residents of the Southeast are cleaning up after a ferocious 2-day outbreak of severe weather. NWS damage surveys have found that at least 42 tornadoes touched down on January 29 - 30, making it the 3rd largest January tornado outbreak since records began in 1950. Here are the largest January tornado outbreaks since 1950:

129 1/21 - 1/22 1999
50 1/7 - 1/8 2008
42 1/29 - 1/30 2013
40 1/9 1/10 1975

As wunderground's Angela Fritz wrote in her blog today, the powerful tornado that ripped through Adairsville, Georgia, northwest of Atlanta, at 11:19 am EST Thursday morning, killing one person, has been rated a high-end EF-3 with 160 mph winds. At least seven other tornadoes in the outbreak were EF-2s. Damaging winds reports for the 2-day period numbered 597, the highest 2-day January total since NOAA's Storm Prediction Center (SPC) began tabulating these in 2000. The severe weather outbreak was fueled an air mass that set many all-time January records for warmth and moisture, as detailed by our weather historian, Christopher C. Burt, in his latest post, A Wild Ride Weather-wise for the Eastern Half of the U.S. the past Four Days.


Figure 1. Damage to the Daiki Corporation factory in Adairsville, GA, after the January 30, 2013 EF-3 tornado. Image credit: Dr. Greg Forbes, TWC.


Figure 2. Severe weather reports for the month of January; 597 reports of damaging winds were recorded January 29 - 30. Image credit: NOAA/SPC.

Mississippi River rising
This week's storm brought widespread rains of 1 - 2" to Missouri and Illinois, along the drainage basin of the stretch of the Mississippi River that was so low as to threaten to stop barge traffic. Happily, the rains have caused the river to rise by more than seven feet over the past week, along the stretch from St. Louis to Thebes, Illinois. Thanks to this much-needed bump in river levels, plus the future run-off that will occur from the snows that have accumulated in Minnesota, Wisconsin, and Iowa, I expect no potential low water closures of the Mississippi until June at the earliest. According to today's newly-released Drought Monitor, though, the area of the contiguous U.S. in moderate or greater drought remained unchanged at 58% this week. It will be dry across the core of the drought region for at least the next week; the GFS model is predicting that the next chance of significant precipitation for the drought region will be Saturday, February 9. Don't bet on this happening, though, since the model has been inconsistent with its handling of the storm. The drought has killed hundreds of thousands of trees across the Midwest, and many more will succumb during the next few years. According to Brian Fuchs, a climatologist with the National Drought Mitigation Center, drought was present in at least isolated spots in all 50 states of the U.S. for the first time in history during 2012.


Figure 3. The water level in the Mississippi River at St. Louis was at -4' early this week, just above the all-time record low of -6.2' set in 1940. However, rains from this week's storm have raised water levels by seven feet. Image credit: NOAA/HPC.


Figure 4. The liquid equivalent of melting all the snow on the ground present on February 1, 2013. Widespread amounts of water equivalent to 0.39" - 2" of rain are present over Minnesota, Wisconsin, and Iowa, which is near average for this time of year. When this snow melts, it will raise the level of the Mississippi River and aid barge navigation. Image credit: NOAA/National Operational Hydrologic Remote Sensing Center.

Links
Adairsville Tornado Recap, Photos, and Video from Angela Fritz

A Wild Ride Weather-wise for the Eastern Half of the U.S. the past Four Days by wunderground's weather historian, Christopher C. Burt.

Tornado Expert Sees "Staggering" Damage in Georgia



Have a great Groundhog's Day and Super Sunday, everyone!

Jeff Masters

Severe Weather Tornado Drought

Updated: 8:50 PM GMT on February 01, 2013

Permalink

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Light Snow
27 °F
Light Snow