If global warming is occurring, why was the winter of 2007-2008 so cold and snowy?

By: Dr. Jeff Masters , 1:38 PM GMT on March 14, 2008

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The planet was much snowier and warmer than usual during the winter of 2007-2008, according to statistics released today by the National Climatic Data Center. Snow cover extent over the Northern Hemisphere during the period December 2007 - February 2008 was the fourth greatest on record, and was the greatest on record for January. Satellite-derived snow cover records extend back to 1967. Some regions of the Middle East, such as Baghdad, Iraq saw their first snow in living memory, and seasonal snowfall records were broken in Wisconsin and a few places in the Northeastern U.S. Surprisingly, the winter also ranked much above average in temperature--it was the 16th warmest December through February period in the 128-year global record. This puts the winter of 2007-2008 in the warmest 13% of all winters. Temperatures this winter were a bit cooler than recent winters because of an ongoing strong La Niña event in the Eastern Pacific Ocean, which has dramatically cooled the ocean surface waters. By one measure (the surface pressure difference between Darwin and Tahiti), February 2008 was the strongest February La Niña event on record. The last time we had a winter this cool was during 2000-2001, which also happened to be the last time we had a major winter La Niña event.


Figure 1. Departure of temperature from average for the winter of 2007-2008. Image credit: National Climatic Data Center.

A normal winter for the U.S.
December 2007 through February 2008 was about average in the contiguous U.S.--the 54th coolest winter on record in the 113 year period of record. The average temperature was 33.2°F (0.6°C), which was 0.2°F (0.1°C) above the 20th Century mean. It was the 18th wettest December-February in the 1895-2008 record. New York experienced its wettest winter on record, and the states of Colorado, Connecticut, Pennsylvania, and Vermont experienced their second-wettest winter on record. Only the South received below normal levels of precipitation, mostly due to a dry winter in Texas.

All time winter snowfall records have already been set in some portions of the Northeast U.S. and Wisconsin. As of March 12, Madison, WI had accumulated 92 inches of snow, smashing the previous seasonal snowfall record of 76.1 inches (193.3 cm) of snow in the winter of 1978-1979. Two locations in the Northeast have set new winter snowfall records, and more records will fall if an average amount of snow falls in March. By the end of February, new snowfall records for the season-to-date were also set in both Telluride and Aspen, Colorado.

An exceptionally warm winter in Northern Europe and Asia, cold in Central Asia
Northern Asia and northern Europe experienced an exceptionally warm winter, with Sweden and Finland recording their warmest winters ever, and Norway, its second warmest. Conversely, Tajikistan recorded its coldest winter in 30 years, and heavy snows in Kazakhstan caused severe flooding when they melted. Snow storms and cold weather in China this winter killed 129 people and did over $21 billion in damage.

Why did we see a cool winter, if global warming is occurring?
It is important to understand the difference between weather and climate. Climate is what you expect; weather is what you get. What we experience in one particular season or year is "weather". Weather has a large variation from year to year, with cool seasons and years mixed in with warms ones. "Climate" is the weather measured on scales of tens of years or longer. One cool winter or year is not an indication that the climate is cooling back to normal. The climate is warming, and unless we see a series of several years of cool conditions, this year's cool winter merely represents a normal fluctuation of the weather. Relatively cool weather is to be expected globally during a strong La Niña event in the Eastern Pacific Ocean, and relatively warm weather is expected during an El Niño event. We shouldn't expect to see record warmth for the globe unless an El Niño event is occurring.

Why did we see record snows this winter, if global warming is occurring?
Beware of global warming skeptics trumpeting record snowfalls this winter as an excuse to doubt that global warming is occurring. One should primarily look at global temperatures on a scale of decades to judge the validity of global warming. Dr. Ricky Rood, who writes our Climate Change blog, put it this way in his current blog, Creeping Onset of Spring and in an earlier blog, Water, water, water:

This year has been very snowy in the northern hemisphere. That it is snowy does not suggest that it is colder. If it gets warmer, it does not mean that we no longer see freezing temperatures in places like Michigan. If it gets warmer there is more water in the atmosphere, and when there is precipitation there will be more precipitation, and if it is below freezing, then that precipitation will be ice and snow. The high mountains near the coast, like the Cascades and the Sierra Nevada would expect more snow. This is also true for the high altitudes parts of Greenland and Antarctica. From a climate point of view it is more important to look at snow cover in the late winter and early spring. Is the snow melting earlier?


Figure 2. Average February arctic sea ice coverage as observed by satellites between 1979 and 2008. Image credit: National Snow and Ice Data Center

Arctic sea ice recovers a bit
It will be interesting to see if this year's heavy Northern Hemisphere snow cover melts earlier than usual, as this will have a big impact on the annual Arctic sea ice melt. We're starting off with more ice surface area in the Arctic than in the past four years--February 2008 Northern Hemisphere sea ice extent was greater than each of the previous four years, thanks to cooler than usual temperatures over much of the Canadian Arctic. However, this was still the fifth lowest ice extent on record for the month of February, and 8% below its extent in 1979 when satellite measurements began, according to the National Snow and Ice Data Center. February was the third straight month that a new monthly minimum Arctic sea ice record was not set, following a string of five months in a row where monthly records were set. The extra sea ice extent will help to reduce the amount of melting this summer, but this effect will probably be overshadowed by the fact that natural wind patterns have forced a large amount of thick, multi-year ice out of the Arctic this winter. This has left much of the sea ice very thin, making it very vulnerable to melting. For the first time on record, the edge of thin first-year ice has pushed beyond the North Pole. IF we get another relatively warm and sunny summer in the Arctic in 2008, we will likely see Arctic sea ice loss surpassing last year's astounding collapse.

Annual WeatherDance contest ready for registration!
Armchair forecasters, now's your chance to shine! WeatherDance, based on teams in the men's and women's NCAA basketball tournaments, allows players to predict which team's city will be hotter or colder on game day in each round of the Big Dance. Beginning March 17, players can make their forecasts at the Weather Dance Web site at: www.weatherdance.org. The site will be updated with cities promptly after NCAA seeding announcements. Team selection occurs March 16 for men and March 17 for women. First round Weather Dance selections must be entered by 11:59 p.m. EST March 19. Players can register now and receive periodic reminders as the game progresses.

"Officially, Weather Dance began as a class project to get students involved in weather forecasting, but we kept it around because it got popular. People think they can do better forecasting than the meteorologists. Well, here's their shot!" said Perry Samson, WeatherDance creator, co-founder of the The Weather Underground, Inc., and Professor in the Department of Atmospheric, Oceanic and Space Sciences at the University of Michigan.

This is the third year for the game. Last year more than 2,000 people played. Most play merely for the thrill, but many science teachers involve their classes as part of meteorology units. The winning teacher will receive an invitation and $500 to join the Texas Tech/University of Michigan Storm Chasing team this spring for a day of tornado chasing. Other winners will receive a Weather Underground umbrella or a copy of the book "Extreme Weather," by Christopher C. Burt.

Jeff Masters

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424. Starwoman
3:32 PM GMT on March 15, 2008
Thanks, Weather456.
Very interesting!!
Member Since: September 11, 2006 Posts: 0 Comments: 196
423. Cavin Rawlins
2:33 PM GMT on March 15, 2008
The remnant low level circulation of once Tropical Cyclone Jokwe

Member Since: July 24, 2005 Posts: 407 Comments: 19076
422. Patrap
2:28 PM GMT on March 15, 2008
No school on Saturday Morning! ,,PLEASE! LOL!
Member Since: July 3, 2005 Posts: 426 Comments: 129093
421. Cavin Rawlins
2:23 PM GMT on March 15, 2008
Coastal Jet along Southern Africa

Other Examples of Coastal Jets

Along the West Coast of the United States, with the core along California and the Baha Peninsula

Along the Coast of the Arabian Peninsula

Along the West Coast of Australia

Along the West Coast of Southern Africa

And the largest and most pronounced, along the West Coast of South America

Brief Description of a coastal Jet

The jet is created as a result of the pressure gradient between relatively higher pressures of the subtropical ridge and lower pressure over land.

The jet is prevented from becoming a sea breeze circulation due to the blockage of coastal mountains. As a result, the jet is channeled along the coast.

The jet is usually favored on the east side of the subtropical ridges where cold air advection (CAA) occurs (cold current).

The jets is assoicated with a stable cool marine layer. This is enhanced by a cold current. Further upwelling of ocean waters further cools and stabalizes the offshore marine layer.

Fog and stratiform clouds often result.

The jet can be tracked using surface observations, satellite imagery (visible and QuikSCAT imagery), ROABS.





Below is an example of the coastal jet along the west coast of South Africa.



Jet Max near 30 knots





Visible Satellite Image



Late last year I did a study on the largest coastal jet, this is one of MODIS image used to analysed the jet showing the infamous coastal cloud deck

Free Image Hosting at www.ImageShack.us

QuickPost Quickpost this image to Myspace, Digg, Facebook, and others!
Member Since: July 24, 2005 Posts: 407 Comments: 19076
420. pottery
2:18 PM GMT on March 15, 2008
Looking at the video and stills from Atlanta, it is amazing to see the damage there, from 60 mph wind.
Was 60 the highest recorded wind ??
Member Since: October 24, 2005 Posts: 0 Comments: 24674
419. Patrap
1:19 PM GMT on March 15, 2008
Severe storm damages buildings in Atlanta

Associated Press / March 15, 2008

ATLANTA - A severe storm ripped through downtown Atlanta last night, injuring several people and damaging skyscrapers, hotels, and two major sports arenas that were filled with thousands of pro and college basketball fans.


National Weather Service officials called the storm a possible tornado, and winds were clocked at up to 60 miles per hour as the storm moved through the city.

Most of the damage was concentrated in downtown Atlanta, police spokesman Ronald Campbell said. He said authorities blocked off roads around the CNN Center, where heavy debris filled the streets. A chair from the skyscraper's lobby sat in the middle of the street, flanked by cars crushed by fallen debris.

A firefighter outside the skyscraper said three people had been transported to hospitals, including a child with head injuries. He said none of the injuries appeared to be life-threatening.

Atlanta Fire Department Captain Bill May said the department was working "multiple incidents" from East Atlanta to downtown. He said part of a loft apartment building collapsed, but he did not know if there were any injuries.

May said a vacant building also collapsed, with no apparent injuries. He said seven to 10 people had been taken to the hospital.

On its website, CNN said its headquarters building sustained ceiling damage, allowing water to pour into the atrium, and windows shattered in the CNN.com newsroom and the company's library. It also said Centennial Olympic Park was damaged.

At the Georgia Dome, where Mississippi State was playing the University of Alabama in a Southeastern Conference Tournament basketball game, catwalks swayed and insulation fell from the roof, sending fans fleeing toward the exits.

The game resumed after a delay of about an hour, but the Georgia-Kentucky game that was to have followed was postponed. SEC officials were considering a scenario that would make up the quarterfinal this morning, with the winner returning later in the day to play in the semifinals.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
417. Caffinehog
6:59 AM GMT on March 15, 2008
Atlanta may not have been that lucky. There are reports of a pancaked apartment building.
Member Since: June 5, 2003 Posts: 0 Comments: 40
416. Caffinehog
6:37 AM GMT on March 15, 2008
The GFS is a little weak on tropical cyclone formation and intensity, but for cyclone tracks and just about all other weather, it's DARN good!
Member Since: June 5, 2003 Posts: 0 Comments: 40
411. TampaSpin
6:12 AM GMT on March 15, 2008
410. moonabove 6:08 AM GMT on March 15, 2008
http://www.holmestead.ca/chemtrails/warming.html


wow you gotta be kidding right....ROFLMAO

Member Since: September 2, 2007 Posts: 179 Comments: 20448
409. TampaSpin
5:12 AM GMT on March 15, 2008
Sleep well on the beach House.....lol
Member Since: September 2, 2007 Posts: 179 Comments: 20448
407. TampaSpin
5:09 AM GMT on March 15, 2008
House i need some shut eye, Keep your eyes open for those that need it....see ya.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
405. TampaSpin
5:02 AM GMT on March 15, 2008
I already called this one they are alittle late.
BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE JACKSON MS 1159 PM CDT FRI MAR 14 2008 THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A * TORNADO WARNING FOR... EAST CARROLL PARISH IN NORTHEAST LOUISIANA... THIS INCLUDES THE CITIES OF...TRANSYLVANIA...LAKE PROVIDENCE... EASTERN MOREHOUSE PARISH IN NORTHEAST LOUISIANA... WEST CARROLL PARISH IN NORTHEAST LOUISIANA...
Member Since: September 2, 2007 Posts: 179 Comments: 20448
404. TampaSpin
4:58 AM GMT on March 15, 2008
There is some major damage occurring right now.......wow.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
403. listenerVT
4:58 AM GMT on March 15, 2008
I'd be mad if there was a tornado warning issued and it wasn't announced to the people in the arena.

Okay, have to sleep.
Member Since: July 11, 2007 Posts: 0 Comments: 5526
402. TampaSpin
4:56 AM GMT on March 15, 2008
The storm South of Crossett heading toward Oak Grove is a Tornado with the appearance of a large one.....
Member Since: September 2, 2007 Posts: 179 Comments: 20448
401. listenerVT
4:54 AM GMT on March 15, 2008
CNN took some damage in Atlanta too...

http://sports.yahoo.com/ncaab/news?slug=ap-sectournament-storm&prov=ap&type=lgns

"numerous windows in CNN Center, headquarters of the cable news network and part of the same complex, were blown out."

On TV they showed a dented CNN car too.

Photos posted via:
http://www.yahoo.com/

"Storm damages sports dome, delays games"
Member Since: July 11, 2007 Posts: 0 Comments: 5526
399. TampaSpin
4:49 AM GMT on March 15, 2008
Man this is some wicked weather in Mississippi.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
397. listenerVT
4:46 AM GMT on March 15, 2008
As luck would have it, I have to get to sleep right now, because I have to open the Bookshop in the morning. But that's okay as long as I'm the only one who has bad luck tonight.

Take care all y'all in the south!! ♡
Member Since: July 11, 2007 Posts: 0 Comments: 5526
396. TampaSpin
4:45 AM GMT on March 15, 2008
394. HouseofGryffindor 4:44 AM GMT on March 15, 2008
I have a friend that lives in downtown Atlanta and he reports everything where he is was just fine. He didn't even know a storm had come through.


Buy him a weather radio......he needs it.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
395. listenerVT
4:44 AM GMT on March 15, 2008
Weather Channel just showed photos from Georgia...including the stadium and Omni Hotel. Looked messy (debris), broken windows, etc.
Member Since: July 11, 2007 Posts: 0 Comments: 5526
393. TampaSpin
4:43 AM GMT on March 15, 2008
7 tornado warnings issued in 30 minutes.......yep i think they are busy.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
392. TampaSpin
4:42 AM GMT on March 15, 2008
Tichula Miss. might have just felt a very bad storm. I hope most knew of the severity before it hit them.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
391. Patrap
4:39 AM GMT on March 15, 2008
NEXRAD Radar
Columbus AFB Base Reflectivity 0.50 Degree Elevation Range 124 NMI Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
390. TampaSpin
4:36 AM GMT on March 15, 2008
Member Since: September 2, 2007 Posts: 179 Comments: 20448
389. Patrap
4:36 AM GMT on March 15, 2008
Statement as of 11:32 PM CDT on March 14, 2008

... A Tornado Warning remains in effect until midnight CDT for extreme
north central Yazoo and southwestern Holmes counties...

At 1132 PM CDT... National Weather Service meteorologists continue to
track a severe thunderstorm capable of producing a tornado. This
tornado was located near Thornton... moving east at 55 mph.

The tornado will be near...
Brozville and 8 miles north of Ebenezer by 1140 PM CDT...
Lexington by 1145 PM CDT...

Lat... Lon 3320 9002 3294 9001 3296 9044 3303 9040
3303 9037 3306 9038 3314 9033 3315 9031
time... Mot... loc 0432z 265deg 48kt 3307 9025


Member Since: July 3, 2005 Posts: 426 Comments: 129093
388. listenerVT
4:33 AM GMT on March 15, 2008
Wild night!!
(And people think it's hard to live in the Northeast and have snowstorms?)

Good luck to all in harm's way. ♥

Member Since: July 11, 2007 Posts: 0 Comments: 5526
387. TampaSpin
4:27 AM GMT on March 15, 2008
Wow these storms are not only producing Tornados but, they are not hiding at all on radar.....what a nite to watch.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
386. TampaSpin
4:24 AM GMT on March 15, 2008
Classic signature......
Member Since: September 2, 2007 Posts: 179 Comments: 20448
385. TampaSpin
4:21 AM GMT on March 15, 2008
The storm between Jackson Miss. and Greenville look really bad.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
384. atmoaggie
4:20 AM GMT on March 15, 2008
Yeah, Tampa, put some coffee on for those NWS guys. They will be busy for a while yet.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
382. sebastianjer
4:18 AM GMT on March 15, 2008
CNN has live report of storm damage in Atlanta on now
Member Since: August 26, 2005 Posts: 1030 Comments: 11197
381. TampaSpin
4:18 AM GMT on March 15, 2008
BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE JACKSON MS 1112 PM CDT FRI MAR 14 2008 THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A * TORNADO WARNING FOR... SOUTHWESTERN HOLMES COUNTY IN CENTRAL MISSISSIPPI... THIS INCLUDES THE CITY OF THORNTON... SOUTHERN HUMPHREYS COUNTY IN CENTRAL MISSISSIPPI... THIS INCLUDES THE CITY OF BELZONI... EXTREME NORTH CENTRAL YAZOO COUNTY IN CENTRAL MISSISSIPPI
Member Since: September 2, 2007 Posts: 179 Comments: 20448
379. Skyepony (Mod)
4:16 AM GMT on March 15, 2008
SPC damage reports. Hail to inch & 3/4 in AR, LA, MS. Winds to 70mph in OK, 1 tornado..

POSSIBLE TORNADO CAUSED DAMAGE TO THE GEORGIA DOME. DAMAGE AT CNN ALSO REPORTED FROM MEDIA. (FFC)

Member Since: August 10, 2005 Posts: 196 Comments: 38766
378. TampaSpin
4:13 AM GMT on March 15, 2008
you all have to see this radar...about as bad as it gets.Link
Member Since: September 2, 2007 Posts: 179 Comments: 20448
377. afcjags03
4:12 AM GMT on March 15, 2008
another cell about to come through Atlanta

Member Since: August 16, 2006 Posts: 0 Comments: 147
376. TampaSpin
4:11 AM GMT on March 15, 2008
Belzoni Mississippi looks like its going to get hit by a bad one.
Member Since: September 2, 2007 Posts: 179 Comments: 20448
375. atmoaggie
4:06 AM GMT on March 15, 2008
Yet, SPC so far has no report on Atlanta. Not even severe winds from one of the most public most immediately broadcasted damage reports in severe WX history.

A bit disappointing that it would take this long or longer.

OK, nevermind...up now.
Member Since: August 16, 2007 Posts: 6 Comments: 12463

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

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