Severe Weather Returns to the Plains, Midwest and Great Lakes Through Saturday

Tom Moore
Published: August 18,2016
After a break from severe weather, conditions are coming together to produce severe storms over parts of the Plains, Midwest and Great Lakes through Saturday. Although the tornado threat will be low, wind damage and large hail will likely be the main impacts.
NOAA's Storm Prediction Center has issued the following severe weather watches:

• A severe thunderstorm watch valid until 12 a.m. CDT for southwestern Wisconsin. This includes Madison and La Crosse, Wisconsin. 
• A severe thunderstorm watch valid until 2 a.m. CDT for far northwest Iowa, southwest Minnesota and southeast South Dakota. This includes Sioux Falls, South Dakota.

Current Radar, Watches and Warnings

In the wake of this severe weather, some much cooler air will be ushered in behind a cold front for the upcoming weekend.
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Below is an outline of when and where severe thunderstorms may develop.

Severe Weather Forecast

Thursday Evening

• Forecast: Showers and thunderstorms are expected to develop late in the day and into the evening from parts of the Dakotas to Minnesota and west-central Wisconsin as a cold front approaches the region.
• Threats: Damaging winds gusts and large hail are the main threats, though the chance of a tornado cannot be ruled out.
• Cities: Pierre, South Dakota | Minneapolis | La Crosse, Wisconsin

Thursday Evening's Thunderstorm Forecast

Friday

• Forecast: Thunderstorms – some severe – will become more numerous and widespread, mainly during the afternoon and evening hours from the Upper Midwest to the central Plains.
• Impacts: Damaging winds gusts and large hail are the main threats, though the chance of a tornado cannot be ruled out.
• Cities: Omaha, Nebraska | Rochester, Minnesota

Friday's Thunderstorm Forecast

Saturday

• Forecast: The severe threat becomes a bit more spotty as the weather system weakens, but some thunderstorms remain possible, mainly from Michigan to Missouri and western Kentucky.
• Impacts: Widely scattered damaging wind gusts possible.
• Cities: Chicago | Indianapolis | St. Louis

Saturday's Thunderstorm Forecast

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Setup For Severe Weather

Late Week Surface Features Across The Central U.S.

A trough of low pressure (dip in the jet stream) will move from the northern Rockies to the northern Plains as a ridge of high pressure aloft (bulge in the jet stream) weakens to the east.
Meanwhile, an area of low pressure and its associated cold front will develop at the surface, and they will slide slowly eastward through Saturday.
Most of this activity will occur from the Plains into the Midwest.

Late Week Jet Stream Forecast

Warm, moist air will be pulled up from the south ahead of the cold front. The front will lift this warm, moist air, and thunderstorms will erupt into Friday.
The system will weaken on Saturday, but there could be widely scattered severe weather from the Great Lakes to parts of the Midwest.
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