Drought continues; Yellowstone fires could become more frequent; 90L set to develop

By: Dr. Jeff Masters , 3:58 PM GMT on July 27, 2011

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Southern Drought Continues

Temperatures continue to soar into triple digits in the Southern Plains this week, and are expected to remain well above average for at least the next month. High air temperatures and low humidity (because of the low soil moisture) will continue to maintain drought conditions in the South unless we see some Gulf-landfalling tropical cyclones—a good remedy for a such an extreme drought.

This year's drought in the South is unprecedented by many definitions. Last year at this time, 0% of the contiguous U.S. was in exceptional drought. Last week, the exceptional drought region covered 11.96%. The area of contiguous U.S. in exceptional drought conditions has never been this high since the Drought Monitor record started in 2000. The highest it had been before June of this year was 7.85% in August of 2002.


Figure 1. Temperature anomaly (difference from average) in degrees Celsius for the period July 1 through July 25 (top) and soil moisture anomaly in millimeters (bottom) on July 25 (from the Climate Prediction Center).

In late June, the U.S. Department of Agriculture designated 213 counties in Texas (84% of the state) as primary natural disaster areas. As I mentioned yesterday, the Texas drought and wildfires are one of the nine billion-dollar disasters of 2011 so far. The National Climatic Data Center estimated that this event had cost up to $3 billion as of June 16. This number is surely rising every day that the South doesn't see rain.

New study concludes Yellowstone wildfires could become more frequent

In a study published this week by the Proceedings of the National Academy of Sciences, researchers have concluded that global warming could have a serious impact on the severity and frequency of wildfires in the Yellowstone region (an area where the states of Montana, Idaho, and Wyoming come together). Historically in this region, fewer than 5% of wildfire occurrences account for 95% of the total area burned. But in a global warming scenario, they found that fire activity could become more severe and more frequent, causing the ecosystem to change dramatically.

Using climate conditions and historical fire data from 1972 to 1999, it was possible to link certain environmental thresholds (temperature, humidity, etc) to past wildfire events. Then by employing the output of various climate models, fire frequency can be forecast well into the future. Figure 2 illustrates the result from one of the climate models they used in the study, and the upward trend of fire activity over the next 100 years. In 1988, a particularly hot and dry year, 36% of the park burned. The study uses this year as a baseline to compare future events.


Figure 2. Figure 2B from the manuscript. Observed burn area (blue line) median of predicted area burned (black dotted line), and ranges (light and dark orange) aggregated over the Yellowstone area defined by the study by Westerling et al. (Source).

What was once a low-probability event could become a high-probability event by mid-century. Fires that have only happened every 100 to 300 years in the past could now be occurring every 30 years in the future. The results of this research has implications for sub-alpine forests across the globe. Warming temperatures and decreasing humidity will lead to more wildfires, and will cost billions of dollars to fight them, if we choose to do so.

Invest 90L

90L has moved west overnight and looks ripe to develop today. While the upper level circulation (500 mb) is very much displaced, the lower level circulation looks strong and coherent through the system's mid-levels (850 and 700 mb). Thunderstorm activity continues to organize, and it appears that a surface circulation is developing. Moisture remains high in the system (around 4.5 g/kg specific humidity) and wind shear should be somewhat favorable as it crosses through the Gulf of Mexico. In terms of track, the statistical models have generally been favoring a Brownsville landfall scenario, but the dynamical models have been inching north over the past day or so. The HWRF is in line with the ECMWF deterministic today, with landfall near Corpus Christi.



The Hurricane Hunters have a mission scheduled for 18Z today (2pm EDT) to investigate whether or not 90L has a closed surface circulation. If it does, given the amount of organized convection and moderate wind speeds (around 34 mph in the latest invest update), the Hurricane Center will probably call this system at least Tropical Depression Four.

If 90L develops this afternoon, I will have another update to look at track and intensity forecasts.

Angela

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this guys killing the blog
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Quoting hydrus:
I will. I hope dry air kills it.


If dry air doesn't kills it, this will be a big time troublemaker for the Caribbean and the CONUS early in the season.
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Quoting hydrus:
I will. I hope dry air kills it.


That Wave might head towards the Bahamas and Florida...

I doubt it will develop into a tropical system... It'll just bring us some rain.
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767. JLPR2
We got a low at the lower end of the wave at 30W.

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Quoting nrtiwlnvragn:
AL 90 2011072718 BEST 0 223N 873W 30 1008 DB 34 NEQ 0 0 0 0 1011


Th HH is pretty much there... yet nada!!!. This is very sneaky system to say the least.
Member Since: August 14, 2008 Posts: 4 Comments: 4881
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Waiting on admin to remove that yo yo, I have latest info for TX regarding storm I wanna post
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Quoting TampaSpin:
Still NO and i say NO Convergence with 90L! We are not gonna see a TD or Storm without Convergence. Still no Closed at the lower levels and still disorganized Yet in the Lower Levels at the Surface!

That map, just like the rest of the CIMSS maps, isn't perfect Tampa. So don't put too much faith in it.
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Report and Ignore this guy.
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Nice neighborhood
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add to ignore list problem solved
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report todd andrews 1 waste of the blog

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Quoting ShenValleyFlyFish:

668. ToddAndrews1

Watch out for the guys with the short haircuts, grey suits and extra shiny shoes.


LMAO!!!
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Quoting MrstormX:
RECON time



yes whats see what the HH says
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AL 90 2011072718 BEST 0 223N 873W 30 1008 DB 34 NEQ 0 0 0 0 1011
Member Since: September 23, 2005 Posts: 13 Comments: 10466
Ritaevac.....trying to fan your way. My daughter lives in Austin.
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Quoting beell:


For sure. Might end up being Mesoscale Convective Vortex #4


Remember that MCV off of Florida, reminds me of that..except this time it is truly tropical.
Member Since: May 27, 2009 Posts: 0 Comments: 4355
Quoting NOLA2005:
Wonder what's taking admin so long to yank this moron?




they are sleeping at the desk i give them a some in too wake up i will send a bear in there may be 2 that would wake them up
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Quoting alfabob:
Sorry but this is TS Don and that coastline needs a warning ASAP..


Why? By the time they put a warning up, it will be gone. Not much difference in a strong summertime thunderstorm and this tropical system anyway (for now).
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Quoting NEwxguy:
amazing when you hit that ignore button,all the free space that shows up. What a wonderful button.


Darn tootin'
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Come on admin, damn
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Quoting Tazmanian:



i said i would stop lol whats move on too 90L plzs
TY and yes please do :)
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668. ToddAndrews1

Watch out for the guys with the short haircuts, grey suits and extra shiny shoes.
Member Since: Posts: Comments:

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About JeffMasters

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