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Storm Impacting the Northwest U.S.; Fire Weather Conditions in Southern California; Severe Weather in the South

A Pacific storm is bringing areas of low elevation rain, moderate to heavy mountain snow, and high winds to the Northwest. Strong Santa Ana winds and very dry conditions are producing elevated to critical fire weather conditions in southern California. Isolated strong to severe thunderstorms are possible through early Wednesday morning across parts of northeast Texas into western Tennessee. Read More >

Overview

A fairly localized cluster of thunderstorms developed over northeast Iowa and southwest Wisconsin Monday evening, July 11th 2017. The storms developed rapidly, becoming strong to severe. Large hail and damaging winds accompanied a few of the storms early, but the main threat quickly moved to heavy rainfall and flash flooding.

Flash flooding occurred across parts of southeast Clayton county Iowa and into Grant county Wisconsin where over 5-8 inches of rain was measured in local rain gages. Social media reports of 4" of rain in one hour were seen, but not confirmed. Voluntary evacuations occurred along the Turkey River and Mill Creek south of Osterdock IA. Washouts occurred on many driveways and roads in both counties, with mudslides also reported in Grant county Wisconsin. 

Some of the higher rainfall totals:

4 miles west of North Buena Vista, Iowa 8.25"
Osterdock, Iowa 8.20"
Guttenberg, Iowa 5.57"
Garber, Iowa 5.39"

 

rainfall
12 hour rainfall radar estimates, ending 7 am July 12, 2017