National Weather Service confirms five tornadoes from August 10 derecho

National Weather Service confirms five tornadoes from August 10 derecho

Climate Society

The National Weather Service confirmed on 12 August that at least five tornadoes, ranging from EF-0 to EF-2, touched down across the Chicago area and northwest Indiana during the derecho on 10 August. The fast-moving squall line produced wind gusts up to 100 mph and prompted tornado warnings across Chicago and its suburbs. Earlier, the service had verified three EF-1 tornadoes in Will and Cook counties, and the mayor of Portage, Indiana, issued an emergency proclamation after roads became impassable and power outages spread.

Actors

National Weather Service Pete Sack NBC 5 Indiana State Police Sgt. Glen Fifield

Locations

Chicago, Illinois, United States Oakbrook Terrace, Illinois, United States Homewood, Illinois, United States Plainfield, Illinois, United States Flossmoor, Illinois, United States Orland Park, Illinois, United States Romeoville, Illinois, United States Tinley Park, Illinois, United States Portage, Indiana, United States Valparaiso, Indiana, United States Merrillville, Indiana, United States

Articles

August 12, 2026
2 total
Multiple tornadoes confirmed during Tuesday's derecho across Chicago area and northwest Indiana
Multiple tornadoes confirmed during Tuesday's derecho across Chicago area and northwest Indiana

NBC 5 Chicago • 12 Aug 21:00

At least five tornadoes, ranging from EF-0 to EF-2, were confirmed by the National Weather Service after a severe derecho storm hit the Chicago region and northwest Indiana on Tuesday.

Credibility 73% Manip. 8% Center
Cleanup underway after multiple tornadoes strike Chicago south and southwest suburbs
Cleanup underway after multiple tornadoes strike Chicago south and southwest suburbs

ABC7 Chicago • 12 Aug 10:57

At least three tornadoes passed through Chicago's south and southwest suburbs, causing tree damage, power outages and structural damage as residents begin cleanup.

Credibility 68% Manip. 7% Center
August 11, 2026
3 total
National Weather Service confirms three EF-1 tornadoes during Tuesday derecho in Chicago area
National Weather Service confirms three EF-1 tornadoes during Tuesday derecho in Chicago area

NBC 5 Chicago • 11 Aug 22:59

The National Weather Service verified three EF-1 tornadoes across Will and Cook counties as a derecho with wind gusts up to 100 mph struck the Chicago region on Tuesday.

Credibility 78% Manip. 8% Center
Portage, Indiana declares emergency after severe storms cause widespread damage and power outages
Portage, Indiana declares emergency after severe storms cause widespread damage and power outages

NBC 5 Chicago • 11 Aug 21:00

A storm system that swept through northwest Indiana left dozens of roads impassable, widespread power outages and school closures, prompting the mayor to issue an emergency proclamation.

Credibility 72% Manip. 8% Center
Chicago area hit by storms with 100 mph gusts and tornado warnings
Chicago area hit by storms with 100 mph gusts and tornado warnings

NBC 5 Chicago • 11 Aug 17:18

A fast-moving squall line produced wind gusts up to 100 mph, possible tornadoes and widespread damage across Chicago and surrounding suburbs on Tuesday.

Credibility 82% Manip. 7% Center

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