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Regional Outbreaks of Severe Weather Through Early Next Week; Early Season Heat Wave across the South

Active spring pattern across the center of our nation with several episodes of severe weather and heavy rainfall expected into next week. The potential for very large hail, long track tornadoes, severe wind gusts, frequent cloud to ground lightning strikes and flash flooding are in the outlook. Furthermore, dangerous early season heat wave continues for the Gulf Coast states into early next week. Read More >

Overview

 

Severe thunderstorms developed across eastern Iowa and northwest Illinois Saturday, July 11, 2020, producing widespread wind damage and very large hail.

The first line of storms came through during the morning, producing damaging wind gusts and reports of quarter to ping pong ball size hail from Independence IA to Tipton IA. A wind gusts of 65 MPH was measured just west of Independence IA.

The second round of thunderstorms developed as a result of an upper level disturbance interacting with an atmosphere characterized by extremely high instability with modest vertical wind shear. Activity initially formed in north central Iowa, producing golf ball to two inch hail from Fort Dodge IA to Waterloo IA. Eventually, storms made their way towards the Cedar Rapids/Iowa City metros, producing widespread wind damage and hail up to baseball size. These storms continued through the Quad Cities metro east towards Princeton IL, Sterling IL and Hennepin IL, producing additional reports of wind damage and winds of 70-90 MPH. Numerous power outages were also reported.

 

Surrounding Office Event Summaries

NWS Chicago

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Sun Illuminating Striations and Mammatus Clouds After Squall Line Exited the Quad Cites Metro (Photo by David Cousins)