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Cold Front Moving Through the Northeast U.S. Monday; Atmospheric River to Impact the Pacific Northwest Midweek

A cold front will cross the Great Lakes and Northeast U.S. through Monday with gusty winds and areas of rain showers. A strong atmospheric river is expected to move into the Pacific Northwest by midweek bringing a threat for moderate to heavy rainfall, gusty winds, and mountain snows for parts of Washington, Oregon, northern California, and the Sierra Nevada. Read More >

August 2, 2020: Southeast Wisconsin Flash Flooding & Heavy Rain Event

Just before 8 PM CDT on August 2nd, thunderstorms developed along a convergence zone near the lake and given the lack of shear and high precipitable water values around 1.0-1.5 inches, storms stalled over southern Milwaukee County for a few hours. This resulted in a prolonged period of very heavy rainfall and localized flash flooding that swamped vehicles and inundated roadways across southern Milwaukee County.

Portions of the area saw around 3.0 inches of rainfall with pockets of higher amounts approaching 5.0-6.0 inches. However, due to precipitation being 0.5-1.0 inch below average for the week prior, it helped mitigate the flooding impacts from being worse. Nonetheless, two flash flood warnings were issued for portions of southern Milwaukee and northern Racine counties. 

Eventually, around 10:30 PM CDT the stall showers finally began to move south into Racine and Kenosha counties where they were able to see some of the action. These areas to the south saw upwards of 1.0-3.0 inches.

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Radar reflectivity loop of the storms that produced flash flooding/heavy rains in southeast WI on August 2, 2020 
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