Source: droughtmonitor.unl.edu
This week’s drought summary: This U.S. Drought Monitor week saw some modest improvements in drought conditions across portions of the Southwest, southern Great Plains, South, lower Midwest, and portions of the Northeast. Drought-related conditions deteriorated in southern California, the southern Great Basin, Texas, Minnesota, and parts of New England. In California, storm activity during the weekend delivered beneficial rain and snow to areas of central and northern California; however, the southern part of the state remained dry. Since January 1, areas of California—including portions of the eastern Sierra and Sacramento Valley—have received less than 25% of normal precipitation. The impact of both short- and long-term dryness in parts of California has been affecting the cattle ranching industry with numerous drought impact reports describing severe impacts to pasture and rangeland conditions as well as reports of ranchers having to sell livestock. Fortunately, another round of storms is expected to impact northern California this week bringing valley rains and mountain snows to the region. In the southern Great Basin, record dryness during the past 6-month period led to expansion of areas of Exceptional Drought (D4) in the eastern Sierra Nevada and southern Nevada. In the Southwest, both Arizona and New Mexico received light rains across parts of the lower deserts as well as some mountain snowfall in northern Arizona and northern New Mexico, providing a much-needed boost to soil moisture levels. Elsewhere, above-normal precipitation during the past 30-to-60-day period and snowfall this week in northern portions of the Texas Panhandle and Oklahoma Panhandle, led to removal of areas of drought. Further to the south in the Hill Country and South Texas Plains, drought intensified in response to persistent warm and dry conditions as well as mounting precipitation deficits ranging from 2-to-8+ inches during the past 90-day period. Conversely, areas along the coastal plains of northeastern Texas received 1-to-2+ inch accumulations during the past week leading to widespread improvements on the map. In the Midwest, wetter-than-normal conditions during the past 30-to-60-day period led to minor improvements on the map in central Illinois and northern Indiana. Likewise, portions of western New York saw improvement on the map in response to recent storm activity.
South: On this week’s map, areas of drought intensified and expanded in the Hill Country and South Texas Plains where warm and dry conditions continued this week. In these areas, 90-day precipitation deficits ranged from 2 to 8 inches, and current soil moisture levels were below normal according to the NASA SPoRT soil moisture monitoring products. According to Water Data for Texas (Dec. 16), monitored water supply reservoirs are currently 79.9% full—with reservoirs in the eastern half of the state ~80–90% full while reservoirs in the western half of the state were generally less than 40% full.
In the far northern portions of the Texas Panhandle and Oklahoma Panhandle, conditions improved on the map in response to short-term precipitation including snowfall observed during the past week with accumulations ranging from 1-to-8+, according to NOAA NOHRSC. In eastern portions of Texas, northwestern Louisiana, and southeastern Oklahoma, precipitation during the past week (1 to 3 inches) led to improvements in areas of Moderate Drought (D1). Average temperatures for the week were below normal (1 to 4 deg F) in the northern Texas Panhandle, Oklahoma Panhandle, and central Oklahoma while other areas in the region were 2-to-10+ deg F above normal.
Looking Ahead: The NWS WPC 7-Day Quantitative Precipitation Forecast (QPF) calls for light-to-moderate liquid accumulations ranging from 1 to 2+ inches across portions of the South with the heaviest totals expected along the Gulf Coast of Louisiana and the Florida Panhandle. Likewise, similar accumulations are expected in the Mid-Atlantic and across southeastern portions of New England where a major winter storm is expected to impact the region starting on Wednesday with a wintry mix of rain, freezing rain, and snow. Areas from Pennsylvania to Massachusetts are expected to receive significant snowfall accumulations ranging from 6 to 20+ inches with New York City and Boston potentially receiving more than a foot of snow. Across much of the Midwest, the Plains, Texas, the Southwest, and southern portions of California and the Great Basin, dry condition are forecasted. Elsewhere in the West, a series of storms is expected to impact an area from Washington state through northern California and eastward through the northern Great Basin and central/northern Rockies. Coastal areas are expecting heavy rainfall accumulations while further inland snowfall accumulations in the higher elevations of the Cascades and northern Rockies of Idaho and northwestern Montana could see 1-to-2 feet of snow. The CPC 6–10-day Outlook calls for a moderate probability of above-normal precipitation across most of the eastern tier of the conterminous U.S., the Upper Midwest, and across much of Alaska where probabilities are higher. Elsewhere, the outlooks call for a low-to-moderate probability of below-normal precipitation across much of the conterminous U.S.—including much of the Midwest and Plains states, the Four Corners states, and California. In terms of temperature, there is a moderate-to-high probability of above-normal temperatures across nearly the entire conterminous U.S. except for the Southeast where normal temperatures are expected.