A blocking weather pattern that is common during the spring, resulted in a couple of slow-moving, low-pressure systems from the end of April through the start of May. These low-pressure systems brought heavy precipitation (more than 2 inches) and drought improvement to the southern Great Plains.

The heavy precipitation across Oklahoma, western Texas, and eastern New Mexico was accompanied by cooler-than-normal temperatures. Farther to the north, drought expanded and intensified across portions of the central to northern Great Plains.

For the West, drought improvements were made to parts of Arizona, Utah, and western Montana.

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

Heavy precipitation (more than 2 inches) resulted in improvements to parts of Oklahoma and Texas. According to the Oklahoma Mesonet, 10 to 16 inches of precipitation was observed across central to southwestern Oklahoma during the past 30 days.

A 2-category improvement was warranted to the north of Midland based on a favorable response among soil moisture indicators. Any precipitation that occurred after 7 a.m. May 9, will be considered in the next U.S. Drought Monitor release. A very tight gradient from excessive wetness across much of Oklahoma to extreme and exceptional drought closer to the Upper and Middle Rio Grande Valley has become established this spring.

Midwest

A majority of the Midwest remains drought-free due to abundant precipitation during the late winter and start of spring

However, abnormal dryness is developing across northwestern Missouri where D0 was added this week.

High Plains

Mostly dry weather prevailed this past week (April 29 to May 5) across the northern to central Great Plains. Based on multiple soil moisture indicators including CPC, NLDAS, and NASA SPoRT along with the Vegetation Drought Response Index (VegDri), extreme drought was expanded to include more of western North Dakota. This D3 expansion coincides with recent wildfires and dust storms.

Soil moisture (below the 10th percentile), VegDri, and 60 to 90-day SPEI supported an expansion of severe drought across central Nebraska. D3 was added to parts of northeastern Nebraska based on VegDRI soil moisture below the 5th percentile, and longer-term extreme drought signal.

Farther to the west, a broad 1-category improvement was made to northeastern Wyoming and adjacent areas of western South Dakota due to recent wetness and a positive recovery among multiple drought indicators. Improvements were also warranted for the upper Green River basin of western Wyoming. However, a drier-than-normal April resulted in a 1-category degradation to parts of southern Wyoming.

West

Recent widespread, heavy precipitation along with consideration of multiple drought indicators such as SPI at various time scales, soil moisture, 28-day average streamflows, and the NDMC drought blends led to a 1-category improvement across eastern New Mexico.

Minor improvements were justified for parts of western and southeastern Montana, but abnormal dryness and moderate drought expanded across parts of north-central Montana that missed out on another week of spring precipitation.

Looking ahead

A cut-off low pressure system is forecast to bring widespread, heavy precipitation to the Southeast with the Weather Prediction Center depicting more than 3 inches of precipitation for southeastern Alabama, central to south Georgia, and the Florida Panhandle through May 12.

Following a wet week, another round of precipitation (1 to 2 inches) is expected from northern New Jersey northward to New England on May 9 and 10. Elsewhere, mostly dry weather is forecast for the Corn Belt along with much of the Great Plains and West.

The dry weather will be accompanied by unseasonably warm temperatures across the northern Great Plains. By May 12, precipitation is forecast to overspread the Pacific Northwest as a low-pressure system tracks inland from the northeastern Pacific.

The Climate Prediction Center’s 6- to 10-day outlook (valid May 13 to 17) favors above-normal precipitation for the Mid-Atlantic, Florida Peninsula, Upper Mississippi Valley, northern to central Great Plains, and much of the West.

Above-normal temperatures are likely for most of the eastern and central U.S. with the largest probabilities (more than 80%) forecast for the Great Lakes. Below-normal temperatures are favored throughout the West.

Brad Pugh is with the National Oceanic Atmospheric Administration and Climate Prediction Center.