California Drought/Polar Vortex Jet Stream Pattern Linked to Global Warming

By: Dr. Jeff Masters , 6:56 PM GMT on April 16, 2014

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From November 2013 - January 2014, a remarkably extreme jet stream pattern set up over North America, bringing the infamous "Polar Vortex" of cold air to the Midwest and Eastern U.S., and a "Ridiculously Resilient Ridge" of high pressure over California, which brought the worst winter drought conditions ever recorded to that state. A new study published this week in Geophysical Research Letters, led by Utah State scientist S.-Y. Simon Wang, found that this jet stream pattern was the most extreme on record, and likely could not have grown so extreme without the influence of human-caused global warming. The study concluded, “there is a traceable anthropogenic warming footprint in the enormous intensity of the anomalous ridge during winter 2013-14, the associated drought and its intensity."


Figure 1. An extreme jet stream patten observed at 00 UTC on January 16, 2014. Color-coded wind speeds at a pressure of 300 mb (roughly 9,000 meters or 30,000 feet) show the axis of the jet stream over North America, with a large upside-down "U"-shaped ridge of high pressure over the West Coast. California is outlined in orange. The strongest winds of the jet stream (orange colors, 160 mph) were observed over the Northeast United States, where a strong "U"-shaped trough of low pressure was anchored. Image generated from the 00 UTC January 16, 2014 run of the GFS model, and plotted using our wundermap.

Using observations and a climate model to diagnose the human contribution to the jet stream pattern
The researchers studied the historical pressure patterns for November - January over North America during the period 1960 - 2014, and found that a strong "dipole" pattern of high pressure over Western North America and low pressure over Eastern North America, such as occurred during the winter of 2013 - 2014, tended to occur naturally during the winter immediately preceding an El Niño event. Since NOAA is giving a greater than 50% of an El Niño event occurring later in 2014, this past winter's dipole pattern may have been a natural expression of the evolving progression towards El Niño. The study also found that the dipole pattern could be intensified by two other natural resonances in the climate system: the Arctic Oscillation, and a variation of ocean temperatures and winds in the Western North Pacific called the Western North Pacific (WNP) pattern. But the dipole of high pressure over California combined with the "Polar Vortex" low pressure trough over Eastern North America during November 2013 - January 2014 was of unprecedented intensity, and extremes in this dipole pattern--both in the positive and negative sense--have been increasing since 2000 (the peak negative value occurred during the winter of 2009 - 2010.) The researchers used a climate model to look at whether human-caused climate change might be interfering with the natural pattern to cause this unusual behavior. They ran their climate model both with and without the human-caused change to the base state of the climate included, and found that they could not reproduce the increase in amplitude of the dipole pattern unless human-caused global warming was included. They concluded, "It is important to note that the dipole is projected to intensify, which implies that the periodic and inevitable droughts California will experience will exhibit more severity. The inference from this study is that the abnormal intensity of the winter ridge is traceable to human-induced warming but, more importantly, its development is potentially predicable." In an email to me, the lead author of the study, Simon Wang, emphasized that the opposite sign of the dipole--an extreme trough of low pressure over Western North American, combined with an extreme ridge of high pressure over Eastern North America--is also expected to be more intense when it occurs, leading to an increase in extremely wet winters in California.

Dr. Joe Romm's post on the study, "Bombshell: Study Ties Epic California Drought, ‘Frigid East’ To Manmade Climate Change", has this quote by climate scientist Michael Mann on the new research:

We know that human-caused climate change has played a hand in the increases in many types of extreme weather impacting the U.S., including the more pronounced heat waves and droughts of recent summers, more devastating hurricanes and superstorms, and more widespread and intense wildfires.

This latest paper adds to the weight of evidence that climate change may be impacting weather in the U.S. in a more subtle way, altering the configuration of the jet stream in a way that disrupts patterns of rainfall and drought, in this case creating an unusually strong atmospheric “ridge” that pushed the jet stream to the north this winter along the west coast, yielding record drought in California, flooding in Washington State, and abnormal warmth in Alaska. The recent IPCC assessment downplays these sorts of connections, making it very conservative in its assessment of risk, and reminding us that uncertainty in the science seems to be cutting against us, not for us. It is a reason for action rather than inaction.



Figure 2. One of the key water supply reservoirs for Central California, Lake Oroville, as seen on January 20, 2014. Thanks to an unusually intense ridge of high pressure over Western North America, California endured its driest November - January period on record this past winter, resulting in the worst winter drought on record. Image credit: California Department of Water Resources.

Other research connecting extreme circulation patterns to human causes
This week's paper by Dr. Wang is the second he has authored which has found a human fingerprint on extreme atmospheric circulation patterns. His 2013 paper, "Identification of extreme precipitation threat across midlatitude regions based on short-wave circulations," discussed how there's been a trend during the period 1979 - 2010 towards a pronounced circulation shift involving the low-level jet stream (LLJ), which is capable of bringing more extreme precipitation events (and droughts) to the mid-latitudes. Using four different climate models, the study found that the circulation shift only occurs when one runs climate models with the effects of human-caused emissions of greenhouse gases like carbon dioxide included; "control" runs of these models using only natural changes to the climate could not reproduce the observed increase in this more extreme circulation pattern. The paper concluded that several recent extreme precipitation events, including those leading to the 2008 Midwest flood in U.S., the 2011 tornado outbreaks in southeastern U.S., the 2010 Queensland flood in northeastern Australia, and to the opposite sense, the 2012 central U.S. drought, could have been influenced by human-caused changes to the atmospheric circulation. The fact that his research helps us understand how human-caused climate change is contributing to higher amplitude jet stream patterns should make them more predictable, potentially saving lives and money.

References
Wang, S, Davies, R.E., and R.R. Gillies, 2013, "Identification of extreme precipitation threat across midlatitude regions based on short-wave circulations," J. Geophys. Res. Atmos., 118, 11,059–11,074, doi:10.1002/jgrd.50841.

Wang, S., Hipps, L., Gillies, R.R., and J.-H. Yoon, 2014, "Probable causes of the abnormal ridge accompanying the 2013-14 California drought: ENSO precursor and anthropogenic warming footprint", Geophysical Research Letters, DOI: 10.1002/2014GL059748. News Release.

Related information
There is an growing body of research exploring connections between human-caused climate change and the increase in unusual jet stream patterns we've seen in recent years. Most of this research focuses on potential linkages between Arctic warming and atmospheric circulation patterns. Below are links to wunderground blog posts on the subject, and to the original research studies and associated press releases.

"The Changing Face of Mother Nature", wunderground guest post by Dr. Jennifer Francis of Rutgers, April 22, 2013.

Extreme jet stream causing record warmth in the east, record cold in the west (January 2013)

Arctic sea ice loss tied to unusual jet stream patterns (April 2012)

Our extreme weather: Arctic changes to blame? (December 2011)

Florida shivers; Hot Arctic-Cold Continents pattern is back (December 2010)

Jet stream moved northwards 270 miles in 22 years; climate change to blame? (June 2008)

Dr. Ricky Rood has done a whole series of posts on climate change and the Arctic Oscillation, including:

Cold Weather in Denver: Climate Change and Arctic Oscillation (8)

Are the changes in the Arctic messing with our weather? The Future of Blocking

Papers linking Arctic warming to an increase in negative AO/NAO conditions
Deser, C., R. Tomas, M. Alexander, and D. Lawrence, 2010, "The seasonal atmospheric response to projected Arctic sea ice loss in the late 21st century," J. Clim., 23, 333–351, doi:10.1175/2009JCLI3053.1.

Francis, J.A., and S.J. Vavrus (2012), "Evidence linking Arctic amplification to extreme weather in mid-latitudes," Geophysical Research Letters, 21 February, 2012. Accompanying article at the Yale Forum on Climate Change, Linking Weird Weather to Rapid Warming of the Arctic.

Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron, 2009, "Winter northern hemisphere weather patterns remember summer Arctic sea-ice extent," Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.

Honda, M., J. Inoue, and S. Yamane, 2009, "Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters," Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

Jaiser, R., K. Dethloff, D. Handorf, A. Rinke, J. Cohen (2012), "Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation", Tellus A 2012, 64, 11595, DOI: 10.3402/tellusa.v64i0.11595

Liu et al. (2012), "Impact of declining Arctic sea ice on winter snowfall", Proc. Natl. Academy of Sciences, Published online before print February 27, 2012, doi: 10.1073/pnas.1114910109. Accompanying press release. My blog post.

Overland, J. E., and M. Wang, 2010, "Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice," Tellus, 62A, 1.9.

Petoukhov, V., and V. Semenov, 2010, "A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents," J. Geophys. Res.-Atmos., ISSN 0148-0227.

Seager, R., Y. Kushnir, J. Nakamura, M. Ting, and N. Naik (2010), "Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10," Geophys. Res. Lett., 37, L14703, doi:10.1029/2010GL043830.

Seierstad, I. A., and J. Bader (2009), "Impact of a projected future Arctic Sea Ice reduction on extratropical storminess and the NAO," Clim. Dyn., 33, 937-943, doi:10.1007/s00382-008-0463-x.

Tang et al., "Cold winter extremes in northern continents linked to Arctic sea ice loss," Environ. Res. Lett. 8 014036 doi:10.1088/1748-9326/8/1/014036. My April 2013 blog post.

Papers linking Arctic warming to Western U.S. drought
Sewall, Jacob O., 2005, Precipitation Shifts over Western North America as a Result of Declining Arctic Sea Ice Cover: The Coupled System Response, Earth Interact., 9, 1–23. doi: http://dx.doi.org/10.1175/EI171.1

Sewall, J.O., and L.C. Sloan, 2004, Disappearing Arctic sea ice reduces available water in the American west, Geophys. Res. Lett., 31, L06209, doi:10.1029/2003GL019133. Accompanying news release.

Papers linking Arctic sea ice loss to changes in summer rainfall
Li Y, LR Leung, Z Xiao, M Wei, and Q Li. 2013, Interdecadal Connection between Arctic Temperature and Summer Precipitation over the Yangtze River Valley in the CMIP5 Historical Simulations, Journal of Climate 26(19):7464-7488. DOI: 10.1175/JCLI-D-12-00776.1 Accompanying press release.

Li, Y, and L.R. Leung, 2013, "Potential Impacts of the Arctic on Interannual and Interdecadal Summer Precipitation in China", Journal of Climate 26(3):899-917. DOI: 101175/JCLI-D-12-00075.1

Screen, J.A., 2013, "Influence of Arctic sea ice on European summer precipitation", Environ. Res. Lett. 8 044015 doi:10.1088/1748-9326/8/4/044015. Accompanying press release.

Wu, B., Zhang R, D’Arrigo. R., and J. Su, 2013, "On the relationship between winter sea ice and summer atmospheric circulation over Eurasia," J. Clim. 26 5523–36

Papers exploring the link between Arctic warming to changes in large-scale atmospheric circulation
Cassano, E.N., Cassano, J.J, Higgins, M.E., and M.C. Serreze, 2013, "Atmospheric impacts of an Arctic sea ice minimum as seen in the Community Atmosphere Model", Int. J. Climatol., in press. (doi:10.1002/joc.3723)

Jaiser, R. et al., 2012, Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation, Tellus A 64, 11595.

Overland, J.E., Francis, J.A., Hanna, E., and M. Wang, 2012, "The recent shift in early summer Arctic atmospheric circulation," Geophys. Res. Lett. 39 L19804, DOI: 10.1029/2012GL053268

Petoukhov, V., Rahmstorf, S., Petri, S., Schellnhuber, H. J. (2013), "Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes" Proceedings of the National Academy of Sciences, (Early Edition) [doi:10.1073/pnas.1222000110]. Easy-to-read description of the paper by the authors, published at http://theconversation.edu.au. Accompanying press release. My March 2013 blog post.

Screen, J.A., and I. Simmonds, 2013, "Exploring links between Arctic amplification and mid-latitude weather", Geophys. Res. Lett. 40 959–64.

Tang, Q.T. at al., 2014, Extreme summer weather in northern mid-latitudes linked to a vanishing cryosphere, Nature Climate Change 4, 45–50, doi:10.1038/nclimate2065


Jeff Masters

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1529. Bowdoin
12:11 AM GMT on April 21, 2014
Climate change is the natural order of the planet and is only slightly influenced by man. The universe is more than who we are people.
Member Since: December 19, 2010 Posts: 0 Comments: 0
1528. RTSplayer
1:06 AM GMT on April 19, 2014
Quoting 1526. iceagecoming:



Early Environmentalists.




The oldest ice core

Published: Tuesday, November 5, 2013 - 11:06 in Earth & Climate

At the root of their quest is a climate transition that marine-sediment studies reveal happened some 1.2 million years to 900,000 years ago. "The Mid Pleistocene Transition is a most important and enigmatic time interval in the more recent climate history of our planet," says Fischer. Earth's climate naturally varies between times of warming and periods of extreme cooling (ice ages) over thousands of years. Before the transition, the period of variation was about 41 thousand years while afterwards it became 100 thousand years. "The reason for this change is not known."

Link





Time line is in reverse order.

It is interesting that the Methane spikes actually follow the warming periods, so these spikes would be indicative that warming released the methane, and then when it cooled the methane went back down.

The obvious question is "where did the methane come from"?

Was it from pre-existing torches, or was it from increased microbe activity?


I just find it amusing they don't know what caused this cycle to change it's period by a factor of 2.5, and the cycle affects regional/continental climate by as much as a 12c margine, but the science is "settled" that man causes GW.

For those who can't do math, a 12C difference corresponds to a 21.6F difference.

I don't think any of us wants to be around for a down peak like those at 25,000 and 135,000, assuming that data is even worthwhile.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
1527. dogsgomoo
10:53 PM GMT on April 18, 2014
Quoting Neapolitan:
For those of us who have always sorted the comments with newest first, placing the comments box at the top makes perfect sense, so we're pleased with the move. Too, the majority of the largest and most visited sites on the web have always--or long--placed the comments box above the comments themselves (and have by default sorted with newest comments first): Huffington Post, Daily Kos, CNN, Fox News, etc., not to mention Twitter and facebook. Nah, I hope the default placement is kept where it is. But having said that--and knowing quite a bit about website design and development--there's probably very little reason users can't pick and choose their own placement of the comments box. So if there's enough whinging, the devs might just do that for y'all... ;-)


I just hope they fix the script issues first before spending time on look and feel. There's some major bugs in the Google API scripts that are loading.
Member Since: March 4, 2008 Posts: 0 Comments: 316
1526. iceagecoming
10:06 PM GMT on April 18, 2014
Quoting 1111. sar2401:



Time, August 24, 2008



Time November 1, 1979



Almost 30 years apart. Is it any wonder many people who "understand" science from magazines like Time are confused?


Early Environmentalists.




The oldest ice core

Published: Tuesday, November 5, 2013 - 11:06 in Earth & Climate

At the root of their quest is a climate transition that marine-sediment studies reveal happened some 1.2 million years to 900,000 years ago. "The Mid Pleistocene Transition is a most important and enigmatic time interval in the more recent climate history of our planet," says Fischer. Earth's climate naturally varies between times of warming and periods of extreme cooling (ice ages) over thousands of years. Before the transition, the period of variation was about 41 thousand years while afterwards it became 100 thousand years. "The reason for this change is not known."

Link


Member Since: January 27, 2009 Posts: 23 Comments: 1061
1525. hurricanewatcher61
9:42 PM GMT on April 18, 2014
Wow! Busted forecast here in east orlando. Dark clouds,clap of thunder a little breezy and now the clouds are no longer dark. And no rain.
Member Since: June 24, 2010 Posts: 0 Comments: 199
1524. Jedkins01
9:42 PM GMT on April 18, 2014
Quoting 1425. Sfloridacat5:

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
243 PM EDT FRI APR 18 2014

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0237 PM TSTM WND GST MACDILL AIR FORCE BASE 27.85N 82.52W
04/18/2014 M 44 MPH HILLSBOROUGH FL ASOS



Run of the mill, 40-50 mph gusts is nothing big in Florida.
Member Since: August 21, 2008 Posts: 0 Comments: 7399
1523. HurrMichaelOrl
9:28 PM GMT on April 18, 2014
It rained heavily here for like 5 minutes. We maybe picked up 0.25" at most.
Member Since: July 13, 2007 Posts: 0 Comments: 1105
1522. Sfloridacat5
9:22 PM GMT on April 18, 2014
Quoting Jedkins01:
Well I'll admit, I was expecting more precip for the peninsula given the strong trough and very deep moisture. However, I should have noticed that upper divergence was quickly shifting northeast away from the gulf. The line not only weakened, but it shrunk and increased forward speed, going from what looked like a solid 1-2 for everyone into a quick half inch instead.

Oh well, WPC you may have won this time, but you got lucky as Central Florida April climatology won the battle, oh well, we cant win them all :)


Some how down here in Fort Myers (at my location) we completely missed out. We had a cloudy to partly cloudy day with no rain. Pretty hard to believe with the setup we had earlier today.
But the line completely broke up and fell apart as it approached our area.

The same thing happened with the last frontal system.
Member Since: September 16, 2007 Posts: 0 Comments: 6592
1521. HurrMichaelOrl
9:22 PM GMT on April 18, 2014
No big deal here north of Orlando. Gusts 20-30 mph, some thunder and lightning and heavy rain which is already beginning to let up a bit.
Member Since: July 13, 2007 Posts: 0 Comments: 1105
1520. WunderAlertBot (Admin)
9:18 PM GMT on April 18, 2014
JeffMasters has created a new entry.
1519. Jedkins01
9:17 PM GMT on April 18, 2014
BTW, why has the website changes brought out all the turds and thorns? All these new posters causing trouble simultaneously. I honestly cannot understand how anyone could waste their life trolling a blog/website. People should be ashamed of themselves.
Member Since: August 21, 2008 Posts: 0 Comments: 7399
1518. Webberweather53
9:15 PM GMT on April 18, 2014
Quoting 1302. ScottLincoln:


It actually is quite plausible and has nothing to do with "having it both ways."

The globe as a whole - all of the storages of heat in the climate system - continue to accumulate heat. This has continued, unabated, for decades. That follows the well-established theory of what would happen due to an enhanced greenhouse effect from the burning of fossil fuels (and some other anthropogenic activities).

Sub-global processes are more complicated. It has been hypothesized that the uneven warming of the globe (both predicted and already observed as occuring) would reduce the temperature gradient between the temperature latitudes and the poles, thus reducing the average speed of the jet stream. At a reduced speed, the jet stream would be more likely to create a blocking pattern; that is, when it is somewhat stuck a particular way, it stays stuck that way longer. If you happen to be in an area experiencing frequent waves of cold air from the arctic, you continue to get cold spells. If you are in an area of ridging, you continue to get ridging and warmer/drier conditions. If you are in an area experiencing the effects of an atmospheric river and frequent rainfall, you stay in that area longer.

There are multiple papers discussing this hypothesis and what it may mean for weather in different regions. The theory of the enhanced greenhouse effect and anthropogenic global warming describes changes to the global climate system, but does not in any way give an expectation of every location seeing warming, or every location seeing more frequent droughts, or every location seeing a steady trend line toward the ultimate equilibrium climate regime. There are many unknowns about how we will get where we are headed, and about the differences between regions.

Bottom line is this: yes, on a local level some places may experience more snow or more cold (in all or just some seasons) due to global warming, even though the majority of the planet will experience warming.


The substantial blocking pattern since the mid-late 2000s is primarily due to NAO phase to follow in toe w/ AMO in about half a cycle length or so (10-15 yrs), thus it makes sense given the warm AMO flip in 1995, the NAO & AO have crashed, thus leading to the observed warming in the arctic due to natural conditions, especially in the vicinity of Greenland where the strongest signals exist in temperature when viewing +AMO-temp correlation via NOAA ESRL. Based on history, even if the AMO regime were to enter its cold phase soon, it would likely take until after 2020 until the predominant positive phase of the AO & NAO makes a return as it did in the 1980s, 1990s, & early 2000s..

AMO correlation to 500mb since beginning of the objective satellite era (1979-2013)



AMO correlation to global temperatures since beginning of the objective satellite era (1979-2013)


Interesting to see negative temperature signals in the Pacific, (a notable signature of La Nina) with the multidecadal AMO in its warm phase +AMO, suggests linkage to ENSO. As evidenced by this graphic I made w/ accordance to ONI, Tri-Monthly Starting Period, El Nino, PDO, etc. the top 7 strongest El Ninos on record, whether they occurred in + or -AMO regimes, observed negative DJFM AMO values several months before the initiation of their subsequent El Ninos. This is consistent with what has been unfolding in the Pacific in terms of WWBs, Oceanic Heat Content, surface currents, SOI, etc. Thus, it is plausible to think due to natural forcing via a formidable oncoming El Nino, another potentially significant global temperature spike is coming as we head towards 2015, but what occurs after that is in question.





Member Since: April 9, 2014 Posts: 0 Comments: 220
1517. Jedkins01
9:12 PM GMT on April 18, 2014
Well I'll admit, I was expecting more precip for the peninsula given the strong trough and very deep moisture. However, I should have noticed that upper divergence was quickly shifting northeast away from the gulf. The line not only weakened, but it shrunk and increased forward speed, going from what looked like a solid 1-2 for everyone into a quick half inch instead.

Oh well, WPC you may have won this time, but you got lucky as Central Florida April climatology won the battle, oh well, we cant win them all :)
Member Since: August 21, 2008 Posts: 0 Comments: 7399
1516. Michfan
9:11 PM GMT on April 18, 2014
Gonna get nailed by that line of storms in east Orlando in about 15 mins. Skies are darkening fast.
Member Since: September 7, 2007 Posts: 0 Comments: 1683
1515. Jedkins01
9:07 PM GMT on April 18, 2014
Quoting 1469. nwobilderburg:




i was gonna make a long comment about this. but i feel this image speaks for how i feel.



LOL perfect
Member Since: August 21, 2008 Posts: 0 Comments: 7399
1514. KEEPEROFTHEGATE (Mod)
9:06 PM GMT on April 18, 2014
Infrared Satellite With Lightning

Member Since: July 15, 2006 Posts: 170 Comments: 53548
1513. ncstorm
9:03 PM GMT on April 18, 2014


Member Since: August 19, 2006 Posts: 13 Comments: 15137
1512. Weathergirlklein
9:01 PM GMT on April 18, 2014
Haven't gotten anything heavy here yet, but I think it's coming our way.
Member Since: April 16, 2014 Posts: 0 Comments: 47
1511. KEEPEROFTHEGATE (Mod)
9:01 PM GMT on April 18, 2014
Member Since: July 15, 2006 Posts: 170 Comments: 53548
1510. Jedkins01
8:59 PM GMT on April 18, 2014
Quoting 1502. opal92nwf:

Alright, I committed myself to not commenting until hurricane season begins, but I have to share this: we've gotten almost 5 inches of rain in the past 24 hours near Ft. Walton Beach, FL. This is on top of the 5 1/2 inches we got a few days ago!

I can't remember having rain totals like this in recent years, except 2009 was similar I believe. Sometimes we can go for awhile without rain here in the spring.


Yeah its amazing how wet its been. We had 9.4 inches of rain in Tallahassee for the month of March, February was also a wet month, and now coming into this event we had just under 5 inches for April, but we picked up another 3 inches in the last 24 hours. So we are sitting pretty with over 9 inches last month and now around 8 so far in April, its crazy.

Rain is always good though, sure is heck is better to get really wet conditions than drought.
Member Since: August 21, 2008 Posts: 0 Comments: 7399
1509. hurricanes2018
8:57 PM GMT on April 18, 2014




Mexico Earthquake: 7.2-Magnitude Tremor Shakes Acapulco, Mexico City

Friday morning at 10:27 a.m. local time, a 7.2-magnitude earthquake struck Mexico's west coast, according to the United States Geological Survey.

Authorities say two people were injured by a falling streetlight, and another was injured after falling off a motorcycle during the earthquake, all in Lázaro Cárdenas, according to La Voz de Michoacán. The Pacific Tsunami Warning Center said they didn't expect a tsunami in Mexico, and there was no threat of damaging waves for Hawaii.

The quake was 32.2 miles deep and was centered northwest of Acapulco. The quake shook Mexico City for at least 30 seconds, with buildings swaying as people fled high rises and took to the streets. Because of the Easter holiday, that city was less crowded than usual, but many locals are vacationing in Acapulco, closer to the epicenter.



Member Since: March 12, 2013 Posts: 12 Comments: 21530
1508. KEEPEROFTHEGATE (Mod)
8:51 PM GMT on April 18, 2014
Member Since: July 15, 2006 Posts: 170 Comments: 53548
1507. MahFL
8:47 PM GMT on April 18, 2014
Quoting 1432. hurricanewatcher61:

Would someone explain the current weather that going on here in central fl. This weather system that has been hyped here for several days now seems to be weakening a little. I know there is still a chance of some severe weather but it looks like the nws in melbourne fl has over done it again with the forecast. Just my own opinion, still keeping a close watch on it though.


Yer here in NE LF we have had about 2 showers of rain, so far 1/3 inch, they were forecasting upto 5 inches..
Member Since: June 9, 2004 Posts: 0 Comments: 3456
1506. LargoFl
8:46 PM GMT on April 18, 2014
Quoting 1502. opal92nwf:

Alright, I committed myself to not commenting until hurricane season begins, but I have to share this: we've gotten almost 5 inches of rain in the past 24 hours near Ft. Walton Beach, FL. This is on top of the 5 1/2 inches we got a few days ago!

I can't remember having rain totals like this in recent years, except 2009 was similar I believe. Sometimes we can go for awhile without rain here in the spring.
indeed our supposed dry season never really kicked in this year huh...grass and plants are loving it.
Member Since: August 6, 2011 Posts: 4 Comments: 38107
1505. DonnieBwkGA
8:45 PM GMT on April 18, 2014
Very heavy rain. 3 3/4" so far today and still coming down. Less that 2" more needed to set record for wettest April here. Temp range 60/64 so far today. Wind fresh out of ENE.
Member Since: June 29, 2013 Posts: 28 Comments: 2034
1504. LargoFl
8:45 PM GMT on April 18, 2014
Member Since: August 6, 2011 Posts: 4 Comments: 38107
1503. HadesGodWyvern (Mod)
8:44 PM GMT on April 18, 2014
Tropical Cyclone Warning Center Perth
Tropical Cyclone Advisory
TROPICAL LOW 16U
3:01 PM WST April 18 2014
================================

At 2:00 AM WST, Tropical Low (1003 hPa) located at 12.3S 91.1E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The tropical low is reported as moving west southwest at 7 knots.

Dvorak Intensity: T2.5/2.5/D1.5/24 HRS

Forecast and Intensity
==================
12 HRS 13.1S 89.8E - 40 knots (CAT 1)
24 HRS 13.8S 89.6E - 50 knots (CAT 2)
48 HRS 15.2S 90.7E - 45 knots (CAT 1)
72 HRS 17.5S 92.8E - 30 knots (Tropical Low)

Additional Information
==================
16U has rapidly developed over the past 24 hours and is close to tropical cyclone intensity.

The system was located using infra-red and microwave satellite imagery. 16U is over warm Sea surface temperatures 29-30C. TC Heat Potential does decrease however south of about 14.0S.

Dvorak: Initial T1.0 was assessed at 1800 17 April. Using a curved band pattern, DTs in the range of 2.5 and 3.0 have been obtained over the past 6 hours. Due to constraints, FT/CI is set to 2.5. System intensity is set to 30 knots [10 minute mean].

CIMSS shear analysis at 1200 UTC indicated generally easterly shear between 10 and 20 knots. The shear is forecast to decrease over the next 24 to 36 hours and the system is expected to further intensify and may reach category 2 intensity on Sunday. An approaching upper level trough will assist poleward outflow late on Saturday and during Sunday. This trough will ultimately cause an increase in shear with strong upper level northwest winds, causing the system to weaken during Monday.

16U is moving towards the west southwest and may cross 90E during Saturday before recurving towards the southeast on Sunday due to the passage of the upper level trough.
Member Since: May 24, 2006 Posts: 50 Comments: 45223
1502. opal92nwf
8:41 PM GMT on April 18, 2014
Alright, I committed myself to not commenting until hurricane season begins, but I have to share this: we've gotten almost 5 inches of rain in the past 24 hours near Ft. Walton Beach, FL. This is on top of the 5 1/2 inches we got a few days ago!

I can't remember having rain totals like this in recent years, except 2009 was similar I believe. Sometimes we can go for awhile without rain here in the spring.
Member Since: May 12, 2012 Posts: 11 Comments: 2542
1501. LargoFl
8:38 PM GMT on April 18, 2014
Quoting 1497. Birthmark:



What's really astonishing is that with AR5 now published, we hear little to nothing about its shortcomings from denialists. That suggests that the IPCC put out a near bullet-proof assessment. Pretty amazing.
I dunno guys,doc for the most part,wants climate change talked about,and im sure that goes either way,attacking folks who dont believe in GW as the diseaster its made out to be.disrupts the blog and creates bad feelings....me i can see some global warming yes, but as you know,i fear global cooling even worse long term..attacking folks because you dont like their view on something just isnt how a blog should run........i remember as a teen,the Hateful rants about the draft and vietnam...oh boy...if you didnt like the draft you were almost an outcast in the REAL world back then...............you young ones dont remember..but back then,as soon as you turned 18...the draft notice and YOU were supposed to report to the draft office and go fight over in vietnam.........you had NO choice...you had to go into the army....................well back then there was alot of hate..on both sides of the issue...............but alot of bad feeling on each side..................why on climate change should hate and bad feelings and name calling be heard today..in 2014....guess times havent changed...if your not on the right side of something...once again your an outcast...........thats wrong folks.....but its just My own personal opinion...doc probably has his own............
Member Since: August 6, 2011 Posts: 4 Comments: 38107
1500. ncstorm
8:36 PM GMT on April 18, 2014



California getting some rainfall..


Member Since: August 19, 2006 Posts: 13 Comments: 15137
1499. ncstorm
8:32 PM GMT on April 18, 2014
Member Since: August 19, 2006 Posts: 13 Comments: 15137
1498. TropicalAnalystwx13
8:25 PM GMT on April 18, 2014
Rain currently being delivered to places that don't need it, with dry conditions where precipitation is needed (and wanted).

Member Since: July 6, 2010 Posts: 113 Comments: 31895
1497. Birthmark
8:18 PM GMT on April 18, 2014
Quoting 1473. yonzabam:



So, in the space of less than an hour, we've had two members who joined in 2007 making their first ever posts, and rubbishing AGW. Interesting.


What's really astonishing is that with AR5 now published, we hear little to nothing about its shortcomings from denialists. That suggests that the IPCC put out a near bullet-proof assessment. Pretty amazing.
Member Since: October 30, 2005 Posts: 7 Comments: 5469
1496. KEEPEROFTHEGATE (Mod)
8:16 PM GMT on April 18, 2014
Quoting 1484. ncstorm:

change..it happens..





and when it does then there is adaptation
Member Since: July 15, 2006 Posts: 170 Comments: 53548
1495. Naga5000
8:16 PM GMT on April 18, 2014
Quoting 1486. LargoFl:

understanding climate change............................................ .................................Link


Sorry Largo, that website is another in the long line of misinformation on the subject designed to look real. This very website (wunderground) has a whole section devoted to helping people understand climate change basics. Link Which is accurate.
Member Since: June 1, 2010 Posts: 4 Comments: 3371
1494. nonblanche
8:16 PM GMT on April 18, 2014
Quoting 1378. nwobilderburg:



California gets some rain :)


Us in the Lahontan Valley too, maybe. Thus we are rushing to get some roofing done, and trying to find space for the stuff in the barn storage shed we are destructing (opposite of constructing.)
Member Since: October 21, 2010 Posts: 2 Comments: 256
1493. Patrap
8:15 PM GMT on April 18, 2014
Member Since: July 3, 2005 Posts: 423 Comments: 127810
1492. Patrap
8:06 PM GMT on April 18, 2014
Of special note is the "Additional Reading"

Additional Reading

Understanding Common Climate Claims: Dr. Richard S. Lindzen; Draft paper to appear in the Proceedings of the 2005 Erice Meeting of the World Federation of Scientists on Global Emergencies.

Geological Constraints on Global Climate Variability: Dr. Lee C. Gerhard-- A variety of natural climate drivers constantly change our climate. A slide format presentation. 8.5 MB.

Thoughts of Global Warming: "The bottom line is that climatic change is a given. It is inescapable, it happens. There is no reason to be very concerned about it or spend bazillions of dollars to try and even things out.
Member Since: July 3, 2005 Posts: 423 Comments: 127810
1491. Sfloridacat5
8:05 PM GMT on April 18, 2014
Pretty cool cloud formations from Fort Myers Beach.
Member Since: September 16, 2007 Posts: 0 Comments: 6592
1490. Patrap
8:04 PM GMT on April 18, 2014
Quoting 1486. LargoFl:

understanding climate change............................................ .................................Link


FUN FACTS about CARBON DIOXIDE

Of the 186 billion tons of carbon from CO2 that enter earth's atmosphere each year from all sources, only 6 billion tons are from human activity. Approximately 90 billion tons come from biologic activity in earth's oceans and another 90 billion tons from such sources as volcanoes and decaying land plants.

At 380 parts per million CO2 is a minor constituent of earth's atmosphere-- less than 4/100ths of 1% of all gases present. Compared to former geologic times, earth's current atmosphere is CO2- impoverished.


Now at 400 ppm..I'd easily say your LINK iz full of manure.
Member Since: July 3, 2005 Posts: 423 Comments: 127810
1489. PedleyCA
8:02 PM GMT on April 18, 2014
Quoting 1473. yonzabam:



So, in the space of less than an hour, we've had two members who joined in 2007 making their first ever posts, and rubbishing AGW. Interesting.


Their brainwashing is kicking in....
Member Since: February 29, 2012 Posts: 0 Comments: 5769
1488. StAugustineFL
8:02 PM GMT on April 18, 2014
Almost the entire state of GA, with it's 57,919 land square mileage, has rain at the moment. Pretty cool.
Member Since: March 8, 2011 Posts: 1 Comments: 802
1487. Patrap
8:01 PM GMT on April 18, 2014


MESOSCALE DISCUSSION 0365
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT FRI APR 18 2014

AREAS AFFECTED...CNTRL AND NCNTRL FL

CONCERNING...SEVERE THUNDERSTORM WATCH

VALID 181957Z - 182130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 83
CONTINUES.

SUMMARY...THREAT FOR ISOLATED STRONG TO DAMAGING WIND GUSTS WILL
PERSIST THROUGH 21Z AS SQUALL LINE CONTINUES ACROSS CNTRL AND NCTNRL
FL. PORTIONS OF THE LINE WILL BEGIN TO EXIT WW 83 BY 21Z. WW CAN BE
LOCALLY EXTENDED IN AREA IF NECESSARY. HOWEVER...OVERALL THREAT DOES
NOT APPEAR PARTICULARLY ROBUST...AND ANOTHER WW ISSUANCE IS NOT
EXPECTED UNLESS TRENDS BEGIN TO SUGGEST OTHERWISE.

DISCUSSION...SQUALL LINE CONTINUES EWD THROUGH CNTRL FL AT AROUND 30
KT. A WELL DEFINED MCV WAS LOCATED ALONG THE NRN END OF THE LINE. SO
FAR ONLY SUB-SEVERE AND MARGINALLY SEVERE WIND GUSTS HAVE BEEN
REPORTED WITH THE STRONGER STORMS. OVERALL DESTABILIZATION OF THE
BOUNDARY LAYER HAS BEEN TEMPERED BY THE CIRRUS CANOPY.
HOWEVER...TEMPERATURES IN THE LOW 80S ARE SUPPORTING UP TO 1000 J/KG
MLCAPE AND STORMS WILL LIKELY CONTINUE FORWARD PROPAGATING EWD
THROUGH THE REMAINDER OF THE WEAKLY CAPPED WARM SECTOR. THE STRONGER
STORMS MAY CONTINUE TO PRODUCE STRONG TO AT LEAST MARGINALLY SEVERE
WIND GUSTS. HOWEVER...GIVEN WEAKER LOW-MID LEVEL FLOW WITH EWD
EXTENT ACROSS CNTRL FL AND THE MODEST THERMODYNAMIC
ENVIRONMENT...ANOTHER WW ISSUANCE EAST OF CURRENT WW WILL PROBABLY
NOT BE NECESSARY.

..DIAL.. 04/18/2014


ATTN...WFO...MLB...TBW...JAX...

LAT...LON 28558213 29198249 29408195 28588143 27298127 26998176
27828178 28558213
Member Since: July 3, 2005 Posts: 423 Comments: 127810
1486. LargoFl
8:01 PM GMT on April 18, 2014
understanding climate change............................................ .................................Link
Member Since: August 6, 2011 Posts: 4 Comments: 38107
1485. hydrus
8:01 PM GMT on April 18, 2014


Earth
Oldest Air on Earth Hiding in Antarctic Ice




Tiny puffs of air from 1.5 million years ago may be locked inside bubbles in the ice nearly two miles beneath Antarctica%u2019s surface. That ancient air, if it exists, would be the oldest sample of Earth%u2019s atmosphere ever recovered.
Antarctic locations (in bright blue) where 1.5 million years old ice could exist. This figure is modified from Van Liefferinge and Pattyn (Climate of the Past, 2013). Credit: Van Liefferinge and Pattyn.

Geoscientists recently identified regions of the frozen continent that potentially preserved the not-so-fresh air. Getting a whiff of the Earth%u2019s oldest breeze would allow an analysis of chemicals in the air at a crucial point from 1.2 million to 900,000 years ago, known as the Mid-Pleistocene Transition.

10 Ways Warmer Winters Wreck Earth

%u201CThe Mid Pleistocene Transition is a most important and enigmatic time interval in the more recent climate history of our planet,%u201D said lead author of the new study published in Climate of the Past Hubertus Fischer of the University of Bern, Switzerland, in a press release.

During the transition, the Earth went from extreme warmth and cooling cycles alternating approximately every 41,000 years to having the cycles change only about every 100,000 years. Sediment samples drilled from the bottom of the ocean recorded the temperature differences, but scientists don%u2019t know why the global thermostat cycles slowed.

Ice samples from other areas yielded 800,000-year-old air bubbles. Those samples showed a lockstep correlation between higher greenhouse gas levels and increased temperatures over thousands of years, according to research published in Nature.

NEWS: NASA%u2019s IceBridge Readies 1st Antarctic Mission

Greenhouse gases, such as methane and carbon dioxide, may have been the culprits behind the Mid-Pleistocene Transition, as well. However, drills will need to pluck a 2.4 %u2013 3.2 (1.5 %u2013 2 mile)-kilometer-long ice core from the Antarctic ice to give scientists the 1.5 million-year-old sample they need.

%u201CA deep drilling project in Antarctica could commence within the next three to five years,%u201D Fischer said. %u201CThis time would also be needed to plan the drilling logistically and create the funding for such an exciting large-scale international research project, which would cost around 50 million Euros.%u201D
Member Since: September 27, 2007 Posts: 1 Comments: 20977
1484. ncstorm
8:00 PM GMT on April 18, 2014
I already said what I thought about the 0 comments and 0 posts bloggers..its quite funny to me..its interesting that they never respond after they post..might want to work on that..

and I can't believe I'm saying this but Nea is right..striking because of a comment box?..comical as well..

change..it happens..


Member Since: August 19, 2006 Posts: 13 Comments: 15137
1483. Sfloridacat5
7:57 PM GMT on April 18, 2014
Storms approaching the Orlando area.
Member Since: September 16, 2007 Posts: 0 Comments: 6592
1482. Patrap
7:54 PM GMT on April 18, 2014
SpaceX Falcon 9 has delivered the Dragon Capsule to Orbit, and the Solar Panels have deployed.
The ISS will be getting a Sunday Morning Easter Bunny Basket delivery.
Member Since: July 3, 2005 Posts: 423 Comments: 127810
1481. Sfloridacat5
7:52 PM GMT on April 18, 2014
We'll have to keep an eye on the southern end of the line as it moves towards the Keys and eventually through the Miami area.
Member Since: September 16, 2007 Posts: 0 Comments: 6592
1480. Chicklit
7:51 PM GMT on April 18, 2014

Special Statement

Statement as of 3:43 PM EDT on April 18, 2014
...A significant weather advisory is in effect for strong wind gusts between 40 and 50 mph over Lake County...western Orange County... northwestern Osceola County...

* until 445 PM EDT.

At 340 PM EDT...National Weather Service Doppler radar indicated a line of storms entering Southwest Lake County that will move northeast at 35 mph across all of Lake County...extreme northwest Osceola County and far western sections of Orange County through 445 PM. These storms will produce locally heavy rainfall amounts of one to two inches...gusty winds to 40 to 50 mph and frequent cloud to ground lightning strikes.

Locations in the path of the storm which may experience strong winds include Clermont...Leesburg...Tavares and Umatilla.

The primary threat will be cloud to ground lightning strikes and gusty winds of 40 to 50 mph...which can cause unsecured objects to blow around...snap tree limbs or cause power outages. Heavy rainfall will temporarily reduce visibility. Seek shelter indoors until the storm passes.
Member Since: July 11, 2006 Posts: 14 Comments: 11280
1479. Patrap
7:51 PM GMT on April 18, 2014
College of DuPage Meteorology
Severe Weather and Flash Flood Warnings
Note: This page will reload every 2 minutes. Warnings are listed with the most recent first.
Click on the station ID to bring up list of recent severe weather statements.
TORNADO WARNING     TAMPA BAY AREA - RUSKIN FL - KTBW 223 PM EDT FRI APR 18 2014
TORNADO WARNING     TAMPA BAY AREA - RUSKIN FL - KTBW 211 PM EDT FRI APR 18 2014


Severe Warnings Issued More Than Three Hours Ago

SVR T-STORM WARNING TAMPA BAY AREA - RUSKIN FL - KTBW 430 PM EDT THU APR 17 2014
Member Since: July 3, 2005 Posts: 423 Comments: 127810

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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.