Late-season Heat and Dryness Causing “Flash Drought” in Lower-Midwest, Southern Plains

Posted on 09/19/2019 11:43 AM

Drought Monitor change mapToday’s National Drought Monitor notes a “rapidly intensifying ‘flash drought’ — attributed in part to extreme late-summer heat — continued to afflict many areas from the lower Midwest and Mid-Atlantic States to the Gulf Coast,” On the other hand, moderate to heavy rain eased or alleviated dryness and drought from the Great Lakes into the Northwest.

In the Midwest, the monitor reports “Reductions to drought intensity and coverage across the northern half of the region contrasted with rapidly intensifying and expanding drought in the south. From Minnesota and northern Iowa into Wisconsin, Michigan, and northern Illinois, widespread soaking rainfall (1-6 inches, locally more than 8 inches) eased or eradicated lingering abnormal dryness (D0) and moderate drought (D1). Conversely, temperatures in the middle and upper 90s coupled with acute short-term moisture deficits (30-day rainfall locally less than 25% of normal) led to an expansion of D0 and D1, most notably from southern Illinois eastward into Kentucky and neighboring portions of Indiana and Ohio.” The update also notes Kentucky is experiencing the same sort of “flash drought” that is being observed across much of the South.

Excessive heat (95-101°F) and “pronounced short-term rainfall deficits (30-day rainfall totaling less than 25% of normal)” have resulted in “quickly escalating drought impacts” in the Southeast. The situation was similar in the central areas of the south, with even higher temperatures and lower rainfall totals (less than 10% of normal over the past month) leading to a sharp increase in drought intensity and coverage. State-wide average topsoil moisture was rated more than 70% short to very short as of Sept. 15 in the Mississippi Delta states and 83% poor to very poor in Texas. Southeastern and north-central areas of Texas and western Oklahoma did see some heavy showers, but relief was localized.

Drought Monitor

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