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Snow in the Rockies; Showers and Thunderstorms Along the Gulf Coast; Potential Winter Storm for Northern Mid-Atlantic and Interior New England

A winter-like pattern will continue over much of the Lower 48 over the next few days, with snow stretching from the Rockies today into the Middle Mississippi Valley on Monday. Showers and thunderstorms will develop along the Gulf Coast and Southeast on Monday. As the storm moves northward late Monday into Tuesday, winter weather is possible from the Central Appalachians to Interior New England. 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)