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

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

Share this Blog
4
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1076 - 1026

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

Time: 19:07:30Z
Coordinates: 21.8N 86.8333W
Acft. Static Air Press: 974.3 mb (~ 28.77 inHg)
Acft. Geopotential Hgt: 300 meters (~ 984 feet)
Extrap. Sfc. Press: 1009.1 mb (~ 29.80 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 250° at 38 knots (From the WSW at ~ 43.7 mph)
Air Temp: 20.2°C (~ 68.4°F)
Dew Pt: 14.7°C (~ 58.5°F)
Peak (10s) Flt. Lvl. Wind: 39 knots (~ 44.8 mph)
SFMR Peak (10s) Sfc. Wind: 22 knots* (~ 25.3 mph*)
SFMR Rain Rate:
Member Since: September 18, 2010 Posts: 0 Comments: 5100
I know its stil very early but the dynamic models are showing some tighting.
Member Since: Posts: Comments:
Time: 19:07:30Z
Coordinates: 21.8N 86.8333W
Acft. Static Air Press: 974.3 mb (~ 28.77 inHg)
Acft. Geopotential Hgt: 300 meters (~ 984 feet)
Extrap. Sfc. Press: 1009.1 mb (~ 29.80 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 250° at 38 knots (From the WSW at ~ 43.7 mph)
Air Temp: 20.2°C (~ 68.4°F)
Dew Pt: 14.7°C (~ 58.5°F)
Peak (10s) Flt. Lvl. Wind: 39 knots (~ 44.8 mph)
SFMR Peak (10s) Sfc. Wind: 22 knots* (~ 25.3 mph*)
SFMR Rain Rate: 17 mm/hr* (~ 0.67 in/hr*)

Recon found 45 mph winds
Member Since: Posts: Comments:
1068. hydrus
Quoting tatoprweather:


If dry air doesn't kills it, this will be a big time troublemaker for the Caribbean and the CONUS early in the season.
That is why I hope dry air kills it...I checked the 10 day model runs, and I was concerned with not only the path the wave is forecast to take, but the weakening of the Bermuda High, and what appears to be almost complete disappearance of high pressure areas over the United States. You probably already saw this..Link
Member Since: Posts: Comments:
Quoting Levi32:


There is a low SW of the Cape Verde Islands, and a tropical wave east of the Antilles. The former has a better chance to cause mischief, though the latter should be monitored as well. I have not delved into them too deeply as 90L should be the primary focus for now. Systems threatening land always take top priority with me.


Do you see this taking a track north of the islands into the Bahamas... or South of the Islands?
Member Since: July 21, 2011 Posts: 1 Comments: 332
Quoting BadHurricane:
Renumbering soon...


Yep
Member Since: May 27, 2009 Posts: 0 Comments: 4436
Levi lets go into your blog
Member Since: July 14, 2008 Posts: 1 Comments: 9628
Time: 19:05:30Z
Coordinates: 21.8833N 86.9W
Acft. Static Air Press: 974.1 mb (~ 28.77 inHg)
Acft. Geopotential Hgt: 298 meters (~ 978 feet)
Extrap. Sfc. Press: 1007.8 mb (~ 29.76 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 262° at 35 knots (From the W at ~ 40.2 mph)
Air Temp: 22.8°C (~ 73.0°F)
Dew Pt: 15.7°C (~ 60.3°F)
Peak (10s) Flt. Lvl. Wind: 36 knots (~ 41.4 mph)
SFMR Peak (10s) Sfc. Wind: 21 knots (~ 24.1 mph)
SFMR Rain Rate: 3 mm/hr (~ 0.12 in/hr)
(*) Denotes suspect data
Member Since: September 18, 2010 Posts: 0 Comments: 5100
Quoting RitaEvac:
I'm not spamming, trying to keep up the pace so people can read my info thru all the junk
Rita, it was spamming for ppl who already have the troll on ignore!
Member Since: Posts: Comments:
Renumbering soon...
Member Since: Posts: Comments:
Time: 19:04:30Z
Coordinates: 21.9333N 86.9333W
Acft. Static Air Press: 973.2 mb (~ 28.74 inHg)
Acft. Geopotential Hgt: 296 meters (~ 971 feet)
Extrap. Sfc. Press: 1006.6 mb (~ 29.72 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 264° at 39 knots (From the W at ~ 44.8 mph)
Air Temp: 24.1°C (~ 75.4°F)
Dew Pt: 15.7°C (~ 60.3°F)
Peak (10s) Flt. Lvl. Wind: 40 knots (~ 46.0 mph)
SFMR Peak (10s) Sfc. Wind: 28 knots (~ 32.2 mph)
SFMR Rain Rate: 1 mm/hr (~ 0.04 in/hr)

Business picking up!
Member Since: Posts: Comments:
1049. Levi32
Quoting floridaboy14:

Levi you back from work or is this just your luch break? the ecmwf wants to develop that closed low southwest of the CV islands and takes it through the northern leewards and north of puerto rico any thoughts?


I'm here for 1 hour right now, then 3 hours of work this afternoon.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
1047. Seastep
Looks like 22N/87W, 1006MB and 30mph
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting tkeith:
sorry folks dont know what is goin on with this troll
Hey you aren't the one with the stripped gears ;)
Member Since: Posts: Comments:
Quoting IceCoast:

I agree. I will not judge the system until they make a center fix, it's a small system. Just figured we'd she a shift in the winds by now.


1006 mb, now but lower winds then I expected. I would classify as a TD for now.
Member Since: May 27, 2009 Posts: 0 Comments: 4436
1042. angiest
Quoting nrtiwlnvragn:


Additional ones in the high thirties, just below TS strength.


Surface was 35, I think.
Member Since: Posts: Comments:
Hey Levi some of the models such as the HWRF have developed 90L as a moderate TS and moving it further North could this mean that the high pressure that would steer a deeper storm may be sliding to the east more and opening up the door for a more NW movement?
Member Since: August 29, 2006 Posts: 22 Comments: 1342
I'm not spamming, trying to keep up the pace so people can read my info thru all the junk
Member Since: July 14, 2008 Posts: 1 Comments: 9628
1033. Jax82
Its very easy, Ignore user, the page is clean again. Now, back to recoon :)
Member Since: Posts: Comments:
Quoting MrstormX:


Tiny little thing, will wait till it's over the center.

I agree. I will not judge the system until they make a center fix, it's a small system. Just figured we'd she a shift in the winds by now.
Member Since: October 17, 2010 Posts: 0 Comments: 1267
Quoting Levi32:


Looks and smells like one. A closed circulation can't be guaranteed, which is why we're waiting for the plane, but it looks likely that it is closed by now.

Levi you back from work or is this just your luch break? the ecmwf wants to develop that closed low southwest of the CV islands and takes it through the northern leewards and north of puerto rico any thoughts?
Member Since: Posts: Comments:

Viewing: 1076 - 1026

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

Top of Page

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.