Severe Storms Likely in the Upper Midwest Through the Weekend

July 22,2016
Strong to severe thunderstorms, with damaging wind gusts and large hail, will take aim on the northern Plains on Friday evening.
In addition, torrential downpours may cause flash flooding in some areas of the northern Plains States.

Current Radar, Watches and Warnings.

(MORE: Storm Damage in the Midwest)
The severe weather is being triggered by disturbances sometimes called "ridge riders" by meteorologists since they are moving along the northern periphery of a hot ridge of high pressure aloft. That high-pressure system is the same one responsible for bringing dangerous heat to the central and eastern U.S. through this weekend.
(MORE: Dangerous Heat Ahead This Week)
Below are more details on the forecast into this weekend.

Thunderstorm Forecast

Saturday

• Forecast: The next disturbance will produce another round of severe weather across the Upper Midwest.
• Impacts: A few storms may turn severe, with large hail damaging wind gusts being the main threats.
• Cities: Fargo, North Dakota | Duluth, Minnesota | Minneapolis | La Crosse, Wisconsin

Saturday's Thunderstorm Forecast

Storm Reports

Friday
Scattered severe storms crossed through the Dakotas during the evening on Friday bringing large hail and gusty winds. In Meadow, South Dakota wind gusts upward of 90 mph were recorded. In Firesteel, South Dakota hail in excess of 2.0" in diameter fell.
Two tornado were reported in eastern Washington state, one near Airway Heights and the other near Mold.
Thursday
Early Thursday morning, severe storms moved through Duluth, Minnesota, where trees and power lines were knocked down. In northern Wisconsin, winds gusted to 75 mph in Ashland.
Later Thursday, the severe threat shifted south and east into southern Wisconsin and northern Illinois. Construction damage was reported on the University of Wisconsin-Madison campus due to 60 mph wind gusts from the storms.  
Ridge Rider Pattern Triggers Storms

Disturbances in the middle portion of the atmosphere ride along the northern periphery of the hot high-pressure system.

A massive ridge of high pressure aloft (bulge in the jet stream) is anchored across a large portion of the nation. Locations underneath this ridge will have a low chance for thunderstorms.
A couple of strong disturbances often called "ridge riders" by meteorologists will move across the top of this ridge, however, and they will produce thunderstorms and some will turn severe.
An upper-level disturbance will progress eastward into the Northeast on Friday.
A second disturbance will produce another round of scattered severe thunderstorms by Friday night and Saturday across the Upper Midwest.
MORE: Lightning Strikes on Iconic Places