New UNL Drought Monitor Up - Looking Deep-Fried To A Crackly Crunch!

[hatrack]

A large ridge of high pressure persisted across the Southeast to southern Plains during this U.S. Drought Monitor period, keeping hot and dry weather entrenched over much of the Southeast drought area. Showers and thunderstorms moved across a frontal band stalled at the northern edge of the ridge, dropping locally heavy rain. Heavy rain also fell as the remnants of Tropical Storm Erin moved along the western and northern edges of the ridge. There were at least 8 deaths reported in Alabama due to the heat, 6 in Missouri, and 1 in Illinois. Meanwhile, scattered monsoon showers and thunderstorms brought rain to parts of the West.

The West: The week was cooler than average across much of the Pacific Northwest, but warmer than average for the rest of the West. There were scattered reports of an inch or more of rain for the week, but much of Montana and Idaho received only a few tenths of an inch. Wildfires remained active and difficult to contain across the northern Rockies and northern Intermountain West. As of August 21, year-to-date wildfires across the U.S. had burned 6.5 million acres of vegetation, 132 percent of the 10-year average. The relentless spread of large wildfires prompted Governor C.L. Otter to declare a statewide disaster emergency in Idaho, where 1.4 million acres had burned. In the Little Lost basin in Idaho, streamflows were the lowest since 2003 and August-September streamflows have been persistently below normal since 1999. USDA NASS reports rate 90% of Montana’s topsoil and 79% of Idaho’s topsoil dry to very dry (short to very short), with pastures poor to very poor for 61% of Idaho and 24% of Montana.

On the U.S. Drought Monitor map, extreme drought (D3) expanded in Idaho and Montana, D0-D2 inched westward across northern Washington, and D0-D3 grew to cover most of Montana. In Colorado, D0 and D1 were pulled back in the southwest and D1 was eliminated in the northeast, but D0 sagged south in north central Colorado to be consistent with dry conditions as depicted by the Standardized Precipitation Index (SPI) out to 90 days. The H/AH impacts boundary was pushed eastward in Wyoming and northeast Colorado. D0-D2 were pulled back in eastern and southern Arizona and western New Mexico to better reflect hydrologic and short-term conditions after a decent monsoon season, and the impacts designation was adjusted accordingly. But two spots of D0 were introduced in north central and southeast New Mexico in areas indicated by the SPI maps as having moisture deficits at 60 days to 12 months.

The Plains and Midwest: Heavy thunderstorms along a frontal band inundated an area from southern Minnesota to northeast Ohio, resulting in significant improvement in drought conditions from the northern Plains to northern Ohio Valley and southern Great Lakes. A large band of 2+ inches of rain, with local reports of 5 inches or more, stretched from eastern South Dakota to New Jersey. In the wettest areas of southern Minnesota, southern Michigan, and northern Indiana and Ohio, the drought depiction improved up to two categories. D0, D1, and/or D2 were pulled back in the Dakotas, Minnesota, Iowa, Wisconsin, Michigan, Illinois, and Ohio. D0 was left in place in southern Minnesota, and D1-D2 in southeast South Dakota and northwest Iowa, along with an H impacts designation, to reflect long-term rainfall deficits, but drought was eliminated at the confluence of Michigan, Indiana, and Ohio. Topsoil conditions improved in many of these states. But in spite of the improvement, ratings remained at 68% dry to very dry for Minnesota and Indiana, 51% for Ohio, and 44% for Wisconsin.

In contrast, south of the frontal band the weather was dry and hot. Many cities in Indiana have implemented mandatory water restrictions. D0-D2 expanded in southern Illinois and Indiana, and D0 edged into eastern Oklahoma and expanded over southwestern Kansas, northern Louisiana, and the panhandles of Oklahoma and Texas. There was also a little expansion of D0 in north central North Dakota where rainfall has been light. The remnants of Tropical Storm Erin dumped 2 to 4 inches of rain, with locally heavier amounts, over parts of central Oklahoma and southwest Missouri, but rainfall amounts dropped off steeply as the system moved east across southern Missouri and Kentucky. D0-D2 expanded across Missouri and Arkansas to reflect the flash drought conditions which bubbled up in the states. Cape Girardeau, Missouri, reached 90 degrees F or hotter every day since July 26, with four of those days 100 F or higher, and had the driest March 1-August 16 period in 47 years. The August 1-16 period was the hottest on record in more than 70 years for Columbia, and the fourth hottest in the 118-year record. Both Arkansas and Missouri had 85% or more of the topsoil rated dry to very dry, with pastures rated poor to very poor in 41% of Arkansas and 55% of Missouri. D3 crept back into Kentucky and poked into northeastern Arkansas. In the meantime, the extreme drought in northeast Minnesota and northern Michigan was taking its toll on the Great Lakes. National Oceanic and Atmospheric Administration (NOAA) hydrologists indicated that Lake Superior was nearing record lows for the month of August, a trend that if continued could break record lows for the months of September and October. As of August 16, the lake was less than 3 inches (6 centimeters) higher than its August record low of 600 feet (182.97 meters) which was set in 1926.

The East and Southeast: Frontal rains brought short-term relief to the drought areas from Pennsylvania to the northern Virginias, while record heat and continued dryness plagued the Southeast for another week. D0 was pulled back in northwest Pennsylvania and northern West Virginia, while D1 was sliced in southern Pennsylvania and pulled back around Richmond, Virginia. The Delmarva D2 shrank under beneficial rains to a spot south of Washington, D.C., but was kept largely to reflect rainfall deficits indicated by the 30- to 90-day SPI.

Crops and pastureland continued to deteriorate for much of the Southeast. Topsoil was rated dry to very dry for 87% or more of the Carolinas, Alabama, Kentucky, and Tennessee, and 74% for Georgia. For crops, 77% or more of the apple harvest was rated poor to very poor across the Carolinas and Georgia, corn was 81% poor to very poor in Alabama, and pastures ranged from 57% poor to very poor in Georgia to 84% in Tennessee. Soil moisture and daily streamflows were near record lows in Georgia, with the Chattooga River at Clayton measuring 2 cfs for an all-time low in 67 years of records. In Alabama, most long-term weather stations from Montgomery northward set or tied records for “string-of-days-above 100 degrees” this week. Brown’s Ferry Number 2 nuclear power plant shut down due to the Tennessee River being too weak and too warm for cooling the reactor. About 15 percent of statewide water providers in Alabama were under some type of restriction. Most of the rest were asking for voluntary measures. Many weather stations from the Montgomery area northward were still reporting the driest or second driest year-to-date precipitation for the period of record. In parts of eastern Tennessee and southwest Virginia, several locations have received no rain at all during August. A few received rain the last week of July. Streamflows were at record low levels and some were actually at 60-80% of the previous record low for the date. Barge traffic has been reduced on the Tennessee River because tonnage is restricted. The dry conditions were compounded by hot temperatures with readings generally in the 90s. The soil is peat-like and normally moist in parts of western North Carolina. However, it has been so dry that the ground is burning. According to forestry authorities in Cherokee County, North Carolina, these underground fires are difficult to battle. The Forest Service issued a statewide burning ban as the number of forest fires and acres burned began setting state records. Many water systems in North Carolina were having near maximum day-water demands each day of the week with many water supply reservoirs declining more than a foot every ten days. Of the 124 local water systems calling for water conservation, 73 were due to drought. In South Carolina, 215 fires were reported during the first half of the month, compared to a ten-year August average of 160. Precipitation for January 1-August 20, 2007, in Greenville totaled 20.52 inches, which is 12.79 inches below normal. For Columbia, the 2007 total was 20.51 inches, or 12.84 inches below normal. This is the second driest such period since 1948 for both Columbia and Greenville. Irrigation ponds in some areas have become nearly exhausted.

On the U.S. Drought Monitor map, a one-category downgrade occurred across much of Georgia, especially in the northern half. Exceptional drought (D4) expanded into western North Carolina and northwest South Carolina, and touched the northeastern corner of Mississippi. Extreme drought (D3) expanded in southwestern Virginia, northeast Tennessee, the Carolinas, and Georgia, and further into the Florida panhandle. Severe (D2) and moderate (D1) drought spread farther eastward in the Carolinas and Georgia, and D1 nosed northward in the Virginias. The AH/A impacts boundary was adjusted southward in South Carolina and Georgia. A spot of D2 was added to Collier/Lee counties in southern Florida to reflect long-term deficits, but 30-day rains of 8-14 inches prompted the pullback of D1 in the Tampa area and northward.

Alaska, Hawaii, and Puerto Rico: Puerto Rico was brushed by the northern rain bands of Hurricane Dean, which dropped 2-4 inches of rain in places. But long-term deficits remained, both for year-to-date and even month-to-date, so the abnormally dry (D0H) area was kept in place. A few stations in Alaska’s abnormally dry area received an inch or more of rain, but most stations received just a few tenths of an inch, so no change was made to the Alaska depiction. A few inches of rain fell in the normally wetter windward locations of Hawaii, but rainfall was generally light, so no change was made to the depiction.

Looking Ahead: High pressure, which has been entrenched over the Southeast and south-central U.S. over the past 2 to 3 weeks, is not expected to weaken significantly during the coming week to 10 days and the subtropical ridge will remain stretched from the Atlantic across the southern tier of the U.S. Zonal mid- to upper-level flow will be present along the U.S./Canadian border. With Hurricane Dean making a second landfall along the eastern coast of Mexico, no tropical storms are present in the Atlantic Basin and no near-term development is forecast. The remnants of Hurricane Dean are expected to continue moving westward and associated impacts are likely to remain south of the U.S./Mexico border.

Weather that could have an impact on drought areas in the next two weeks: 1) no major storm systems are forecasted to impact the Southeast in the next 6 to 10 days, but a chance of afternoon showers and thunderstorms will be present. 2) Moist easterly flow south of the high pressure ridge favors above-average precipitation for Florida and the southern Plains. 3) Above-average precipitation also is likely for much of the Mid-Atlantic coast in association with frontal systems that stall out on the northern edge of the subtropical ridge. 4) Above-normal temperatures are expected to cover much of the western half of the nation and Alaska. 5) Zonal flow through the northern Plains and Upper Midwest will keep precipitation chances below average during the 6-10 day period. 6) Monsoonal moisture will continue in the Southwest but the amount of activity is dependent on the track taken by the remnants of Hurricane Dean. Projections point to the most significant impacts remaining south of the U.S./Mexico border. 7) Drier and warmer-than-average conditions are expected for much of interior Alaska, with wetter-than-average conditions for the Panhandle.

The NWS 8- to 14-day outlook for August 30-September 5 calls for a pattern similar to the 6- to 10-day outlook with low amplitude flow persisting. Above-average temperatures will likely occur from the Rockies westward including Alaska as the mean storm track remains north of the U.S./Canadian border. However, the subtropical ridge over the eastern U.S. begins to weaken in the forecast, allowing for a cooling trend for much of the east-central U.S. Near- to above-normal precipitation is likely for the Southeast and south-central U.S. as the ridge breaks down. A stable Canadian air mass becomes established over the Upper Midwest, bringing drier-than-average conditions to the region. Most of interior Alaska is expected to remain warmer and drier than normal while nea- to above-average precipitation falls in the Panhandle.

Author: Richard Heim/Jay Lawrimore/Liz Love-Brotak, NOAA/NESDIS/National Climatic Data Center

http://drought.unl.edu/dm/monitor.html

[phantom power]

1. And all the stuff in the middle that isn't dry, has been flooded.

[kestrel91316]

2. Wellllllll.......weren't AL and GA WAY too wet and swampy before anyway???

[amandabeech]

3. That map makes me wonder where all the food is coming from.

So much of the good farmland and pastureland seems to have been either fried or flooded, or both!

No worries, though, because food prices aren't in the "core" inflation rate!