Relentless Severe Storms, Flooding Rain to Hammer Storm-Weary Upper Midwest Into Early Saturday; Threat Spreads to East Coast This Weekend

Brian Donegan
Published: July 21,2017
This relentless siege of severe thunderstorms and flooding rain will persist through the weekend from the storm-weary upper Midwest to the East Coast.
Multiple clusters of storms are currently dropping southeastward from the upper Mississippi Valley to the lower Great Lakes and parts of the Ohio Valley. These thunderstorms have a history of producing flash flooding, damaging wind gusts, large hail and even isolated tornadoes.
(MORE: View National Interactive Radar Map | Difference Between a Watch and a Warning)

Current Radar, Watches and Warnings

Early Friday evening, a severe thunderstorm with destructive winds over 70 mph moved through Elk Grove Village, Illinois, uprooting large trees throughout the village adjacent to O'Hare International Airport in Chicago's northwest suburbs. There were also reports of half-dollar-sized hail and standing water in the area.
Additionally, major flooding engulfed Schaumburg, Illinois, just west of Elk Grove Village, and on top of that, golf-ball-sized hail was reported in this village.
Friday afternoon, multiple brief tornado touchdowns were reported west of Kelliher, Minnesota. Grain bins and other farm buildings were damaged, according to a National Weather Service storm report.
Flash flood watches have been posted in parts of the upper Mississippi Valley. Several rivers are still above flood stage from western and southern Wisconsin into the north side of Chicagoland, including the Fox and Des Plaines rivers.

Current Flood Alerts

The setup for this latest round of severe weather involves an energetic jet stream punching across the upper Midwest and Northeast into this weekend. At the surface, hot, humid air is surging into the Midwest, Great Lakes and East – an ideal airmass for thunderstorms to develop, grow and persist.

Severe Weather Forecast

Saturday

• Forecast: Clusters of strong to severe thunderstorms are expected, once again, from the upper Midwest to the Great Lakes, Ohio Valley and portions of the mid-Atlantic states. These clusters may last into the overnight hours in parts of these regions.
• Threats: Damaging wind gusts and large hail are the primary threats, but an isolated tornado can't be ruled out. Localized flash flooding is also possible.
• Cities: Detroit | Duluth, Minnesota | Cleveland | Pittsburgh | Washington D.C. | Baltimore | Philadelphia

Saturday's Thunderstorm Forecast

Sunday

• Forecast: Scattered severe thunderstorms appear poised to fire up, yet again, from the Great Lakes into parts of the Northeast and mid-Atlantic states.
• Threats: Damaging wind gusts and large hail are the main threats, though an isolated tornado cannot be ruled out. Localized flash flooding will again be possible.
• Cities: Detroit | Cleveland | Pittsburgh | Philadelphia | Baltimore | Washington D.C.

Sunday's Thunderstorm Forecast

(MAPS: 7-Day U.S. Rainfall Forecasts)

Recap: Severe Weather in the Northeast, Flash Flooding in the Upper Midwest Thursday

Thursday, the National Weather Service confirmed two tornadoes touched down in Erie County, New York, and one touched down in Allegany County, New York.
An EF2 tornado ripped through Hamburg, some 10 miles south of Buffalo, with 105-mph maximum winds at about 12:30 p.m., followed by an EF1 tornado in Holland with 95-mph maximum winds roughly 20 minutes later.
The Allegany County tornado caused damage near the town of Angelica at approximately 1:40 p.m. and was rated EF1 with maximum winds of 95 mph.
(NEWS: State of Emergency Declared in Hamburg, New York, After Tornadoes Leave Damage)
Early Thursday morning, a cluster of thunderstorms triggered flash flooding and mudslides in parts of western Wisconsin and southeast Minnesota.
This followed immediately on the heels of Wednesday's derecho, which tore through parts of six states from South Dakota to northwest Indiana.

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MORE: Severe Storms in the Midwest, Northeast

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