NWS Chicago ILSV.W 0259August 21, 2026
Severe Thunderstorm Warning: Boone and Winnebago, IL
The National Weather Service office in Chicago issued a severe thunderstorm warning for Boone and Winnebago in Illinois, which was in force until 4:45 p.m. local time on August 21. It was the 259th severe thunderstorm warning the NWS office in Chicago issued in 2026. Illinois had 118 severe thunderstorm warnings in August 2026, against 61 in an average August of 2008-2025 (Illinois's severe thunderstorm warnings by year).
ExpiredWarning
In force for 1 hour; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, Chicago IL
- Area
- Boone and Winnebago
- State
- Illinois
- Level
- Warning
- Issued
- 3:45 p.m. CDT, August 21, 2026
- Expires
- 4:45 p.m. CDT, August 21, 2026
- CAP severity, certainty, urgency
- Severe, Observed, Immediate
- VTEC event
- KLOT SV.W 0259
- Official source
- National Weather Service: the notice at its source
Source: National Weather Service: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. A U.S. Government work, in the public domain.
The notice as issued
SVRLOT The National Weather Service in Chicago has issued a * Severe Thunderstorm Warning for... Eastern Winnebago County in north central Illinois... Boone County in north central Illinois... * Until 445 PM CDT. * At 344 PM CDT, a severe thunderstorm was located near Machesney Park, moving east at 25 mph. HAZARD...60 mph wind gusts and quarter size hail. SOURCE...Radar indicated. IMPACT...Hail damage to vehicles is expected. Expect wind damage to roofs, siding, and trees. * Locations impacted include... Rockford, Belvidere, Loves Park, Machesney Park, Roscoe, Poplar Grove, Candlewick Lake, Cherry Valley, Capron, Timberlane, Garden Prairie, and Caledonia.
What the agency told people to do
For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways.
Source: National Weather Service: the notice at its source. The text is the agency's, unedited. A U.S. Government work, in the public domain.