Drought continues; Yellowstone fires could become more frequent; 90L set to develop
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
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TS BUSTED FORECAST ALIBI
I'm not really sure it will make a Cat 3 but for sure a low end cat 2.... and I said that yesterday.....
Taco :o)
If I'm not mistaken mid-level dry air caused (2009)Erika's demise.
You're right.
Revision: No well organized hurricane takes in mid level air while over open water.
Sigh. They could be perfectly right. The NHC may have the track down pat. But I've never seen that cone not move. We'll see I guess.
THIS RIDGE...BY THE WAY...IS EXPECTED TO HELP STEER TS DON TOWARD THE
LOWER TX COAST...AND BLOCK ANY FURTHER GAINS IN LATITUDE THAT WOULD
BRING GREATER IMPACTS TO OUR REGION. ON THE CURRENT FORECAST
TRACK...EFFECTS OVER THE NORTHWEST GULF COAST REGION WILL BE
MINIMAL...AND AT THIS TIME LIMITED GENERALLY TO INCREASING WINDS
AND SEAS OVER THE COASTAL WATERS LATE THURSDAY THROUGH FRIDAY.
Transmitted: 27th day of the month at 20:32Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Mission Purpose: Investigate third suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 09
A. Time of Center Fix: 27th day of the month at 20:01:40Z
B. Center Fix Coordinates: 22°08'N 86°49'W (22.1333N 86.8167W)
B. Center Fix Location: 68 miles (110 km) to the N (1°) from Cancún, Quintana Roo, México.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 29kts (~ 33.4mph)
E. Location of the Estimated Maximum Surface Wind: 26 nautical miles (30 statute miles) to the NNW (336°) of center fix
F. Maximum Flight Level Wind Inbound: From 101° at 34kts (From between the E and ESE at ~ 39.1mph)
G. Location of Maximum Flight Level Wind Inbound: 25 nautical miles (29 statute miles) to the NNW (329°) of center fix
H. Minimum Sea Level Pressure: 1001mb (29.56 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 22°C (72°F) at a pressure alt. of 313m (1,027ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 26°C (79°F) at a pressure alt. of 348m (1,142ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 16°C (61°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 3 nautical miles
Remarks Section:
Maximum Flight Level Wind: 34kts (~ 39.1mph) in the northwest quadrant at 19:49:40Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
I can see Don forming into a weak Cat 1 storm pretty easily before landfall (Not much more than that however). Personally I hope Don gets larger without strengthening too much. Would be a gift to those thirsty Texans!
I'll post pics!
Is there a G-IV mission planned as well? Dropsondes in the upstream eviromment would likely be pretty useful for refining the trac.
CI MWS ; MWS ; MSLP &nbs p; MSLP &nbs p; Saffir-Simpson
Number (Knots) (MPH) (Atlantic) (NW Pacific) Category
1 25 KTS 29 MPH ; & nbsp; &nb sp; ; (Approximate)
1.5 25 KTS 29 MPH
2 30 KTS 35 MPH 1009 mb 1000 mb
2.5 35 KTS 40 MPH 1005 mb 997 mb
3 45 KTS 52 MPH 1000 mb 991 mb
3.5 55 KTS 63 MPH 994 mb 984 mb
4 65 KTS 75 MPH 987 mb 976 mb 1 (64-83 KTS)
4.5 77 KTS 89 MPH 979 mb 966 mb 1 (64-83 KTS); 2 (84-96 KTS)
5 90 KTS 104 MPH 970 mb 954 mb 2 (84-96 KTS); 3 (97-113 KTS)
5.5 102 KTS 117 MPH 960 mb 941 mb 3 (97-113 KTS)
6 115 KTS 132 MPH 948 mb 927 mb 4 (114-135 KTS)
6.5 127 KTS 146 MPH 935 mb 914 mb 4 (114-135 KTS)
7 140 KTS 161 MPH 921 mb 898 mb 5 (136+ KTS)
7.5 155 KTS 178 MPH 906 mb 879 mb 5 (136+ KTS)
8 170 KTS 196 MPH 890 mb 858 mb 5 (136+ KTS)
CI -- Current Intensity
MWS -- Mean Wind Speed
MSLP -- Mean Sea Level Atmospheric Pressure in Millibars
Stay Thirsty wunderblogger's"
I don't! My house after Ike and I was one of the lucky ones I still had a house!
As good an educated guess as any right now. I would like to see much more consensus from the model runs overnight. Now that we have a LLC that can be tracked properly.
Viewing: 1951 - 1976
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