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Cold Front Dropping South Across the Western U.S.; Watching Threat for Tornadoes and Flooding in the South

A cold front will push south across the Western U.S. into Tuesday with mountain snow and areas of gusty to high winds. An area of low pressure will form along this front on Tuesday and bring a potential for severe thunderstorms with tornadoes and excessive rainfall in the lower to mid Mississippi River Valley. To the north, heavy snow is possible in parts of the upper Midwest. Read More >

Overview

Fast Facts:

A supercell thunderstorm developed over Will County, Illinois in the very early morning hours of August 17 shortly after 2 a.m. This storm would end up sustaining itself for well over an hour as it moved into northwest Indiana. The storm was substantially deep and very well organized, a combination that resulted in large hail and severe winds. While severe storms certainly can produce both, to happen concurrently in the same location is much more rare especially with hail of 1.5" and larger and winds of 70+ mph. This storm had this based on reports, degree of damage, and radar signatures. Hail and wind damage occurred from Peotone, IL in Will County to Wheatfield, IN in Jasper County.

Radar Cross Section
NWS Chicago radar (KLOT) cross section of the powerful thunderstorm.
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Additional recaps can be found on the NWS Chicago Past Events Page
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