US Drought Monitor and Summary, Jan. 17, 2020

Source: droughtmonitor.unl.edu
This Week’s Drought Summary: Warmer than normal temperatures were common this week over the eastern half of the continental U.S., while temperatures were primarily near normal over the western half, with a few exceptions. Moderate to heavy precipitation was common this week along and east of the Interstate 35 corridor, excepting parts of the Northeast and the Florida Peninsula. In the West, moderate to heavy precipitation also fell in some of the higher elevation areas. For more details on the geographic distribution of precipitation and temperature anomalies, please see the regional paragraphs below. The only exceptional drought occurring in the United States, on Maui, was removed this week after a major precipitation event in Hawaii, where other improvements were also made. Heavy rainfall in northern and eastern Puerto Rico also ended the moderate drought there. In the central and eastern continental U.S., drought conditions generally improved in areas that received heavier precipitation, while some degradation occurred in locations in Texas and Oklahoma that remained drier. The depiction of moderate drought and abnormal dryness also changed in Idaho, Washington, and Oregon, where recent precipitation (or lack thereof) affected mountain snowpack and short-term precipitation deficits. For more details on changes made to the drought depiction, please see the regional paragraphs.

South: Most of the South had warmer than normal temperatures this week, though widespread rainfall led to reduction in drought conditions in parts of the region. Temperatures ranged from 10 to 15 degrees warmer than normal in Mississippi and Tennessee to generally 5 to 10 degrees above normal in Oklahoma and Texas. Excluding south Texas, moderate to heavy rain fell across the portion of the region to the east of the Interstate 35 corridor. The highest rain amounts, with some locations exceeding 3 inches, fell upon north-central Texas, southeast Oklahoma, Arkansas, far northeast Louisiana, and northern Mississippi. The heavy rain in east Texas and adjacent portions of Louisiana, Arkansas, and southeast Oklahoma led to improvement in drought and abnormally dry conditions in these areas, where short-term precipitation shortages were lessened, and streamflow improved. In areas west of the more widespread precipitation in Texas and Oklahoma, some of the drought and abnormally dry areas were expanded where short-term precipitation deficits grew.

Looking Ahead: Another winter storm system is forecast to traverse the Central Plains, Midwest, and eastern continental U.S. from Thursday, January 16 into the weekend of Saturday the 18th, delivering widespread rain, snow, and a mix of winter precipitation types. For Jan. 16-21, the National Weather Service Weather Prediction Center is forecasting over three-quarters of an inch of precipitation in a widespread area from coastal central and northern California northward through the high elevation areas of western Washington and Oregon. Precipitation is also forecast in the central and northern Sierra Nevada, and in some of the high elevation regions of the Rocky Mountain Front Ranges and Intermountain West. Widespread precipitation is forecast from West Texas northeastward along and north of the Interstates 44 and 70 corridors and in the Ohio Valley and Northeast, where amounts may exceed an inch in some areas. Temperatures will vary in the High Plains and West during this period, while generally warmer than normal conditions over the eastern continental U.S during the first half of the weekend are forecast to be replaced by colder than normal weather afterward. For Jan. 21-25, the National Weather Service Climate Prediction Center is forecasting mainly warmer than normal temperatures from the High Plains westward, and below-normal temperatures in the South, Southeast, and Northeast. Below-normal precipitation is favored during this period in the Northeast, Great Lakes and Ohio Valley, while above-normal precipitation is favored in the Pacific Northwest, the Central and Southern Great Plains, and areas in between.