8/9 Drought Monitor - Driest 10-Month Period On Record For TX; "Flash Drought" Hits Upper MW Corn

[hatrack]

National Drought Summary -- August 9, 2011

The discussion in the Looking Ahead section is simply a description of what the official national guidance from the National Weather Service (NWS) National Centers for Environmental Prediction is depicting for current areas of dryness and drought. The NWS forecast products utilized include the HPC 5-day QPF and 5-day Mean Temperature progs, the 6-10 Day Outlooks of Temperature and Precipitation Probability, and the 8-14 Day Outlooks of Temperature and Precipitation Probability, valid as of late Wednesday afternoon of the USDM release week. The NWS forecast web page used for this section is: http://www.cpc.ncep.noaa.gov/products/forecasts/.

Summary: Exceptional drought continues its hold on the southern states of Texas, Oklahoma, New Mexico and neighboring states. Recent extreme high temperatures have combined with below average precipitation over the last few weeks to create drought impacts in the Corn Belt states of Iowa, Illinois and Indiana.

Northeast and Mid-Atlantic: An area of abnormally dry conditions is expanded in the states of Vermont and New Hampshire. Over the last 30 days, rainfall totals of one to five inches below average have been reported across much of the northern tier of these states. Streamflow data is averaging around 20% of normal in some area creeks and rivers for this time of year.

Southeast: Abnormally dry conditions now exist in the mountains of western North Carolina and eastern Tennessee, abnormally dry conditions. This area has not received as much rainfall as normal for this time of year, particularly over the last 30 days, and streamflow data in the area are also beginning to show signs of less surface water flowing through the mountain creeks and rivers. In the Charlotte area, as much as six inches of rain feel this week, but primarily on the already drought-free area. Elsewhere in North Carolina, some improvement is warranted in the north central part of the state, with a change from D1 to D0 status. Hydrological impacts persist, however, and that is indicated as the primary impact.

A swath of heavy rain through east central South Carolina is cause for a one-category improvement from Columbia to Charleston. Local totals were one to two inches or more above normal for the week. An area of extremely heavy precipitation centered in northeastern Georgia was also beneficial. Scattered thunderstorm activity in Florida was considered, but no changes were made on the peninsula. The impacts of previous extreme drought in the Florida panhandle have subsided, and D3, or Extreme Drought, conditions are removed.

South: Texas continues to suffer from unprecedented drought. Climate data show that the Lone Star State is in its driest ten-month period ever on record, in over a century of data. This is unprecedented territory, as the precipitation deficits mount, and triple digit temperatures continue to increase water demand. Significant, ongoing impacts related to agriculture, water supply and natural vegetation conditions have been reported. Widespread Exceptional Drought (D4) is maintained in large part across the region.

The western edge of the D4 area in the Oklahoma and Texas Panhandles continued to erode thanks to monsoon rainfall amounts of nearly an inch in some areas. Boise City, OK, received 0.95 inch in the last seven days, compared to an October 1 - July 31 total of 3.78 inches. Elsewhere, D3 was expanded eastward across the remainder of southeastern Oklahoma, over the Red River and into western Arkansas due to a combination of short-term dryness with excessive heat, residual effects of moderate drought from the preceding year, and local impact reports. The Oklahoma Biological Survey reported that streams in southeastern Oklahoma were going dry, threatening up to three endangered mussel species.

Elsewhere, a large area of six to eight inches of rainfall across northeastern Mississippi and northwestern Alabama removed dry conditions and no drought is depicted on this week’s map. In northwestern Louisiana, drought impacts and precipitation deficits are accumulating, resulting in an increase in the D4 area. Much of the Exceptional Drought is due to shortages of two to three feet of rainfall over the last 18 months. At the opposite corner of the state, rain was a welcome sight and gave reason for one-category improvement from Baton Rouge and New Orleans, LA to Biloxi, MS.

Central and Midwest: Drought impacts have developed quickly in the Corn Belt states of South Dakota, Iowa, Illinois and Indiana. Multiple days of 100+ degree temperatures have combined with below average precipitation over the last few weeks to stress the corn plants, particularly in areas with sandier soils or areas with delayed planting due to a wet spring. This “flash drought” is depicted as D1, moderate drought, in southeastern South Dakota, and from southeast Iowa to central Indiana. The soybean regions have not reported similar conditions thus far.

A storm track across northeastern Kansas and into southwestern Missouri produced locally three to eight inches above average precipitation for the current Drought Monitor period. One-category improvements are made in several counties, approximately from Manhattan to Lawrence, KS, and also over part of the Ozarks between Kansas City and Springfield, MO.

West: Very few changes were made in the western region of the United States. Widespread rainfall south and southeast of Denver, CO, have improved the drought conditions and a one-category improvement is made in Jefferson, Park, El Paso, and Lincoln counties and the surrounding area. Drought impacts to producers in this area are not as severe as were reported in July. In the San Luis Valley in south central Colorado, exceptional drought impacts continue despite recent precipitation over the last few weeks, and this area remains in D4 status.

Hawaii, Alaska and Puerto Rico: The Big Island is suffering from lack of rainfall in the agricultural areas of north, west and central regions. D2 was expanded to include a larger area of north central Hawaii, and moderate drought conditions now encompass most of the western half of the island.

The abnormally dry areas in Alaska held steady this week. Despite widespread reports of precipitation across the state, they did not alleviate the current D0 regions and were below normal for the period. Many stations are maintaining rainfall deficits of up to three inches below average for the last month.

In Puerto Rico, residents continue to be bombarded by above average precipitation this summer, and no drought conditions are depicted on the map. For the last 30 days, rainfall totals of more than eight inches above normal are common across the island.

Looking Ahead: The first few days of the next U.S. Drought Monitor period will bring scattered showers throughout the monsoon region, centered on New Mexico. A swath of this scattered convective activity may be found from north to south, just east of the Rocky Mountains, but may not alleviate the severe to exceptional drought conditions in the Great Plains states. A strong system will move the middle part of the country, centered on Arkansas. Texas will continue to be “high and dry”, with little drought relief in sight over the next week.

The extended outlook over the next six to ten days calls for continued above normal temperatures across throughout the central U.S., from Arizona to Mississippi and north to the Great Lakes. This area has already been affected by extremely high maximum temperatures, and the heat trend will continue. Cooler than normal temperatures are expected across Alaska, the Pacific coast and along the Atlantic coast from Virginia to northern Florida. Below normal precipitation pattern will persist as well throughout much of the most severe drought areas, and above normal precipitation projected over the northern High Plains states and far Pacific Northwest and Northeast.

Author: Laura Edwards, Western Regional Climate Center

Dryness Categories

D0 ... Abnormally Dry ... used for areas showing dryness but not yet in drought, or for areas recovering from drought.

Drought Intensity Categories
D1 ... Moderate Drought
D2 ... Severe Drought
D3 ... Extreme Drought
D4 ... Exceptional Drought

Drought or Dryness Types
A ... Agricultural
H ... Hydrological



Updated August 10, 2011

EDIT/END

http://droughtmonitor.unl.edu/

[phantom power]

1. "Flash drought"

Is this some damned new thing from The Twitter?

[kestrel91316]

2. Wow. From that map, one might logically infer that Gawd Hates Texas (TM) for

some reason.......

[Historic NY]

3. or maybe Rick Perry.....wasn't he praying for moisture?

[CJvR]

4. Didn't they...

...hold a big prayer meeting over that a while back?
Perhaps they should try a differnt God next time!