Great Plains still feeling drought stress
![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.)](https://hpj.com/wp-content/uploads/2023/08/Great-Plains-still-feeling-drought-stress.png)
A strong area of mid-level high pressure, anchored over the southern tier of the country, continued to promote above-normal temperatures and mostly dry weather across the Rio Grande Valley, Texas, and the lower Mississippi Valley.
Weekly temperatures (Aug. 2 to 8) averaged more than 6 degrees Fahrenheit above normal across portions of Louisiana, Texas, and southern New Mexico. The persistence of this pattern led to rapidly developing and intensifying drought across Texas and the lower Mississippi Valley.
The monsoon remains suppressed with increasing short-term drought across Arizona, New Mexico and southwest Colorado. Frequent rounds of heavy rainfall occurred from the central Great Plains southeastward to the middle Mississippi Valley. During the first week of August, parts of Missouri received 5 to 10 inches (locally more) of rainfall. The wet start to August resulted in improving drought across parts of the Corn Belt. Farther to the north, drought continues to intensify across Wisconsin.
South
Increasing 30 to 60-day precipitation deficits coupled with excessive heat and high evapotranspiration rates support a widespread 1-category degradation across Texas, Louisiana, and southwest Mississippi. 30 to 60-day SPI/SPEI, NDMC’s short-term blend, and soil moisture were leaned on for these degradations. During the past two months, temperatures have averaged 2 to 6 degrees above normal across parts of Texas and Louisiana. Heavy rainfall (more than 2 inches) resulted in a 1-category improvement to northern and eastern Oklahoma along with parts of Tennessee.
Midwest
Heavy rainfall (2 to 8 inches, locally more) during the first week of August prompted widespread improvements to Missouri, southern Iowa, Illinois, and Indiana. A few 2-category improvements were justified across Missouri and Illinois where more than 6 inches of rainfall occurred and there was support from the short to long-term indicators. Despite widespread, heavy rainfall (more than 1.5) across western Iowa this past week, improvements were limited given the longer-term drought indicators and a reassessment can be made in subsequent weeks.
Severe (D2) to extreme (D3) drought was expanded across Wisconsin based on continued dryness dating back to the late spring. Exceptional (D4) drought was added to northern portions of Douglas and Ashland counties in northern Wisconsin. Superior has received 4.71 inches of rain since May 1 which is the driest on record.
High Plains
Above normal precipitation since the beginning of July and a lack of support from the long-term indicators led to a 1-category improvement to west-central Nebraska and bordering areas of Kansas. Recent beneficial precipitation also resulted in improving conditions across parts of the Dakotas and Wyoming. Short-term drought was expanded across northeast North Dakota which remained to the north of the storm track. The lack of monsoon rainfall this summer resulted in the addition of short-term drought to southwestern Colorado.
West
The suppressed Monsoon and associated above-normal temperatures resulted in a 1-category degradation across Arizona and New Mexico. Recent rainfall supported a decrease in abnormal dryness (D0) in southeast Montana, while a 1-category degradation was made to parts of northern Montana based on worsening short-term indicators.
Looking ahead
According to the Weather Prediction Center, during the next five days (Aug. 10 to 14), moderate to heavy precipitation (0.5 to 2 inches, locally more) is forecast for the Midwest, Ohio and Tennessee Valleys, and Northeast. Farther to the south, little to no precipitation and above-normal temperatures are forecast to persist across the lower Mississippi Valley and Texas. Scattered thunderstorms may result in local amounts in excess of 0.5 inches for the Four Corners region.
The Climate Prediction Center’s six- to 10-day outlook (valid Aug. 15 to 19) depicts large probabilities (more than 60%) for above-normal temperatures throughout much of the West, southern Great Plains, and Gulf Coast. Probabilities for above-normal temperatures decrease farther to the north with a slight lean toward below-normal temperatures across the northern Great Plains. Above-normal precipitation is slightly favored across the northern Rockies, northern Great Plains, upper Mississippi Valley, and New England, while below-normal precipitation is more likely across the southern Great Plains and lower Mississippi Valley