Drought continues to expand in the Plains

This week, a powerful storm system crossed from the Great Plains into the Great Lakes, bringing widespread rain and thunderstorms to parts of the Midwest, and a historic blizzard to portions of the Upper Midwest, especially in northern Wisconsin and Michigan near Lake Superior.

Total precipitation amounts exceeded 2 inches in a large area of the western Great Lakes, while lighter amounts, mostly 0.5-3 inches of precipitation, fell across parts of the southern and eastern contiguous United States.

Improvements to ongoing drought and dryness occurred across large portions of the Midwest, parts of the lower Mississippi River Valley, and in the Northeast outside of northern New England. Heavy rain and, in some areas, mountain snow, fell across parts of the Northwest, locally improving drought conditions. However, significant deficits in snow still exist in many parts of the West, including the Pacific Northwest, which limited the longer-term benefits of the precipitation that fell.

Much of the Southwest, and the central and southern Great Plains, missed out on precipitation, and instead dealt with a dry, warm and windy week. Precipitation deficits, and lack of snowpack in the mountains, continued to worsen amid high evaporative demand, leading to widespread worsening of abnormal dryness and drought, especially in South Dakota and Nebraska, southwest Kansas, southern Colorado, New Mexico, Arizona, Nevada, and parts of Oregon that missed out on precipitation.

The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture and the National Oceanic Atmospheric Administration. (Map courtesy of NDMC.)

South

Parts of east Texas and Arkansas benefitted from localized rains of at least 2 inches. Elsewhere, deep south Texas, western Texas, and northern and western Oklahoma were mostly dry. Temperatures across the region were warmer than normal, with readings varying widely from a degree or two above normal to 9 to 12 degrees Fahrenheit above normal.

Soil moisture levels improved and precipitation shortfalls lessened in parts of east-central Texas and southeast Arkansas, leading to localized improvements to drought conditions in these areas. Heavy rain in Dallas improved local conditions.

Warm, dry and windy conditions were the rule elsewhere in the southern Great Plains and deep south Texas, leading to localized degradations in central and northern Texas, deep south Texas, south-central and northwest Oklahoma, and the Oklahoma and Texas panhandles.

Midwest

A strong low-pressure system traversed the Great Plains into the Midwest with it, bringing widespread strong winds, locally heavy rain and a powerful blizzard to the Upper Great Lakes.

Recent precipitation and improvements in soil moisture and precipitation deficits led to local improvements in Missouri and Iowa. Weekly temperatures were 3 to 9 degrees below normal in northwest Minnesota, as cold air wrapped around the powerful storm system, while temperatures in the southern half of the Midwest were 3 to 12 degrees warmer than normal for mid-March.

High Plains

In the southern half of the High Plains region, warmer-than-normal weather continued this week amid mainly dry and frequently windy conditions. Degradation in drought conditions was widespread across Nebraska and southern parts of South Dakota. A deadly wildfire in western Nebraska, the Morrill Fire, has burned a record amount of land for Nebraska wildfires. This fire, and others across Nebraska, occurred amid weather conditions favorable for fire growth and a background of worsening drought conditions.

The Great Plains of southwest Kansas and southeast Colorado also saw worsening drought and abnormal dryness this week, as precipitation deficits continued to mount along with warmer-than-normal temperatures this winter and early spring. Large precipitation deficits and above-normal evaporative demand over the last several months led to extreme drought development in parts of the Black Hills in southwest South Dakota. Colder temperatures and some precipitation kept conditions unchanged (and mostly free of drought or abnormal dryness) in North Dakota and northern South Dakota.

West

Current drought conditions in the West continued to be headlined by snow drought this week. The Sangre de Cristo Mountains and portions of the San Juan Mountains in southern Colorado and northern New Mexico saw widespread worsening conditions

 Overall dry and warm conditions worsened both precipitation deficits and snowpack conditions in these areas. Some snow-water monitoring sites in the region have seen near-full or full melting of snowpack. Amid the snow drought, localized degradations occurred in southwest Idaho, while heavier mountain snows improved snowpack in some mountain ranges in parts of western Montana, leading to localized improvements. The effectiveness of this locally renewed snowpack in improving soil moisture will be analyzed further in the weeks ahead.

Looking ahead

Through the evening of March 23, the National Weather Service Weather Prediction Center’s forecast depicts mostly dry weather across a large swath of the contiguous U.S.

Precipitation totaling 0.5- to 1-inch may fall in parts of northwest Montana and the Idaho Panhandle. Elsewhere, the forecast calls for precipitation amounts to remain at or below 0.5 inches, with most of the Great Plains, Mississippi and Lower Ohio River Valleys, and the Gulf Coast states likely to remain completely dry.

Looking ahead from March 24 to 28, the National Weather Service Climate Prediction Center forecast strongly favors warmer-than-normal temperatures in most of the West, especially in the Southwest, and across much of the Great Plains and South. Near- or below-normal temperatures are favored from northern North Dakota eastward through the Great Lakes into much of the Northeast.

Above-normal precipitation is favored in the Idaho Panhandle and northwest Montana. Elsewhere in the contiguous U.S., below-normal precipitation is more likely, especially from the Great Plains to Utah, Nevada, the Desert Southwest and California.

Curtis Riganti is with the National Drought Mitigation Center.