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Excessive Rainfall and Tropical Storm in the South; Severe Thunderstorms in the Midwest

Excessive rainfall may produce considerable, potentially life-threatening, flooding across the lower Mississippi River Valley and central Great Lakes region through tonight. Tropical Storm Arthur will move northeastward along the Texas coast today and then move inland over southwestern Louisiana by tonight. An outbreak of severe thunderstorms is expected across portions of Illinois and Indiana. Read More >

Overview

In the afternoon of August 8th, 2020, thunderstorms developed across eastern Wyoming and western South Dakota. These brought large hail and damaging winds to the area through the evening. One storm that developed over the Black Hills produced grapefruit-sized (4.5 inch) hail! As the storms shifted eastward, they formed a line, developing into a mesoscale convective system as more storms converged together. The main threat changed from hail to strong winds, with nearly 80 mph gusts reported across south central South Dakota. As the storms passed, magnificent mammatus was seen by many.  Image
Pactola (R. Strom)
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