U.S. Drought Monitor Report for the Week Ending June 28 (Text)
Strong high pressure in the upper levels of the atmosphere dominated the southern U.S. with the storm track over the northern states. This U.S. Drought Monitor (USDM) week began with a strong cyclonic storm system moving through the central U.S. and dragging a frontal zone across the southern Plains and Southeast drought areas. Beneficial rains (2 inches or more) fell in some areas, but long-term precipitation deficits and continued hot temperatures limited improvements to the drought depiction.
The Upper Midwest, Northeast, and Mid-Atlantic: Two-plus-inch rains fell over parts of New York and New England this USDM week, but below-normal amounts fell to the south. D0 expanded further into southern New Jersey and into southeast Pennsylvania and northeast Maryland where the 30 to 60-day Standardized Precipitation Index (SPI) was quite dry. The last 30 days have been dry across Maryland, most of Pennsylvania, and western New York, but the corresponding SPI values have been mixed, indicating that the dry percent of normal precipitation values are not rare occurrences for some stations based on their data history.
Beneficial rains in the western Great Lakes resulted in the removal of the D1 in the Minnesota Arrowhead and contraction of the D0 over the Michigan Upper Peninsula. D0 was left over Michigan’s Keweenaw and northern Houghton counties where less rain fell and deficits remained at many time scales.
Southeast: Beneficial (2+ inch with locally 5-inch) rains prompted the contraction of D0 in northern Alabama, northern Georgia, and extreme northwest South Carolina, and slight contraction of the D1 in northwest Georgia. The D4 was dented in central Louisiana over Grant Parish where the rains were enough to make the 30-day SPI wetter than normal. In east- central Florida, D1-D2 were pulled back from Orange to Volusia counties, and in southern Florida areas of D1-D2-D3-D4 contracted. The rainfall helped improve soil moisture conditions on a statewide basis, but June 26 U.S.D.A. reports still had 50 percent or more of the topsoil in each of the Southeast states short or very short of moisture. South Carolina still had over 80 percent of the topsoil short or very short. Long-term precipitation deficits remained, with the last 6 months 15 inches or more behind normal along coastal Alabama and Mississippi and parts of southern Florida, and rainfall deficits of 20 inches or more widespread for the last 12 months. Hot temperatures this week resulted in continued above-normal evaporation, with maximum temperatures in the 90?s and low 100?s, setting new records in some locations early in the USDM week. A spot of D1 was added around Tuscaloosa County in Alabama, which missed the rainfall this week. While the rainfall helped, several large wildfires still raged across Florida.
The lack of rainfall has resulted in extremely low river and creek levels, with many wells going dry, and has begun to impact southwest Georgia water utilities that rely on groundwater. The dry weather and hot temperatures have ravaged crops, with a fourth to half of several crops (corn, cotton, peanuts, sorghum, and soybeans) rated in poor to very poor condition across several southeast states (Louisiana, Mississippi, Alabama, Georgia, South Carolina, and North Carolina). The hard soils and hot temperatures have made successful sprouting of seed difficult and, due to lack of forage, farmers are sending cattle to feedlots or selling cattle.
The Plains: This was another very hot and dry week for much of the southern Plains. Beneficial rains occurred in a few areas of eastern and southern Texas, but deficits have been so large that little change was made to the USDM depiction. Improvement was made where 3 inches or more of rainfall was recorded. D3 was pulled back in Navarro, west Henderson, and southwest Van Zandt counties; D4 was pulled back in Willacy, southern Kenedy, and eastern Hidalgo counties; and D4 shrank around Shelby to San Augustine counties.
There were more than 150 reports of record hot maximum temperatures in Texas, over 20 in Oklahoma, and 15 in Arkansas this week, with the hottest reports including 118 degrees F in Paducah, Texas (June 27), 116 in Castolon, Texas (June 21), and 115 in Castolon and Penwell, Texas (June 26). According to the Electric Reliability Council of Texas, operator of the state’s major power grid, electricity demand peaked at 62,752 megawatts on the 27th, a record for June. Several wildfires continued to flame across west Texas into Oklahoma. Through June 27, Del Rio had the driest October to June in the 1906-2011 record, San Antonio had the second driest October-June in a period of record beginning in 1871, and Austin Mabry was third driest for October-June in records going back to 1856. D4 expanded along the Rio Grande River around Laredo and Del Rio to reflect the record to near-record dryness. June 26 U.S.D.A. reports listed 90 percent or more of the topsoil short or very short of moisture in Texas and Oklahoma. For Texas, 80 percent or more of the pasture and rangeland was rated in poor or very poor condition, and half or more of the winter wheat, corn, soybeans, cotton, peanuts, and oat crops were rated poor or very poor.
Hot and dry conditions prevailed north of Texas. D0 expanded across eastern Oklahoma and most of Arkansas, with spillage into southern Missouri and parts of southern Kansas and northeast Texas. May was extremely wet in Arkansas and Missouri, but the last 4 weeks have seen little rain. The recent dryness, coupled with hot temperatures and increased evaporation, dried out the topsoil and shrank stream levels, resulting in the D0 expansion. The U.S.D.A. topsoil moisture statistic for Arkansas jumped from 60 percent last week to 77 percent short-very short this week. In Oklahoma, the statistic jumped from 80 percent last week to 90 percent this week. The U.S.D.A. statistics for percent of pasture and rangeland in poor or very poor condition jumped about 10 percent compared to last week for these states, with 52 percent poor to very poor in Oklahoma and 26 percent in Arkansas. A fifth of the sorghum and two-thirds of the cotton crop were rated poor to very poor in Oklahoma, while in Arkansas a fifth of the soybeans and a fourth of the corn crop were rated poor to very poor. D1 and D2 also expanded in Oklahoma and adjacent parts of Kansas. Localized rain in southeast Nebraska resulted in a shift in the position of the D0 there. D0 expanded in northwest Kansas into southwest Nebraska based on 30-60-day dryness.
With record or near-record long-term precipitation deficits and low stream and groundwater levels, the A impacts designation from the Southwest to central Plains was removed, leaving an AH impacts designation stretching from the Southwest to the Southeast United States. An A impacts area was added to the new D0 in Arkansas and southern Missouri to reflect the short-term nature of the dryness there.
The West: The week was drier than normal across most of the West, with virtually no rain falling over the extreme Southwest where temperatures were well above normal. Scattered showers dropped a few tenths of an inch of rain on eastern parts of New Mexico and Colorado, but not enough to warrant improvement. There were more than 35 reports of record hot maximum temperatures in New Mexico during the past 7 days. D0-D1-D2-D3 expanded in northwest New Mexico and parts of Colorado. D0 expanded across Arizona into parts of southern Nevada and adjacent California. Hot temperatures and unseasonably strong winds continued to desiccate the soil in northeast Arizona where the Navajo and Hopi tribes have declared emergencies to try to deal with failing wells. D0-D1-D2 expanded in northeast Arizona with D0- D1 spillage into adjacent southeast Utah.
June 26 U.S.D.A. reports listed 90 percent or more of the topsoil short or very short of moisture in New Mexico; 80 percent or more of the pasture and rangeland in poor or very poor condition for New Mexico, 60 percent for Arizona, and 40 percent for Colorado. By June 28, several large wildfires were burning in Arizona, New Mexico, Colorado, and California.
Hawaii, Alaska and Puerto Rico: Above-normal precipitation and streamflow in east central Alaska resulted in contraction of the northeast corner of D0 in the state. In Hawaii, the last 7 days were wetter than normal over the northern islands but drier than normal over the southern islands. Some areas on the south side of the Big Island were drying out, but the current depiction still represented the situation well, so no changes were made. The week was drier than normal across much of Puerto Rico, but rainfall has been above normal for the last 60-90 days.
Looking Ahead: An upper-level ridge will continue to dominate the southern U.S. during the next 5 days (June 29-July 4), with the storm track staying to the north. Tropical Storm Arlene will bring a chance for rainfall to Deep South Texas and an inch or more of rain may fall along the coast from Florida to the Carolinas. Half an inch of rain is expected along the Gulf coast and a few areas in the north, but otherwise the country should have drier than normal weather. Temperatures are expected to be above normal except in the Northwest and near the track of Arlene.
The CPC 6-10 day outlook and 8-14 day outlook indicate above- normal precipitation is expected for July 5-13 from the Northeast and Mid-Atlantic coast to the central Rockies, with below-normal precipitation across the west coast, Arizona to west Texas, and most of Alaska. The northern Great Plains to Great Lakes are expected to be cooler than normal while the southern half of the country will continue warmer than normal beneath the upper ridge. The Pacific Northwest is expected to be warmer than normal, while cooler-than-normal temperatures should dominate over western Alaska and near to warmer-than- normal temperatures are expected over eastern Alaska.
SOURCE: National Drought Mitigation Center
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