NWS St Louis MOSV.W 0258September 20, 2026
Severe Thunderstorm Warning: Monroe and Jefferson, IL and MO
The National Weather Service office in St Louis issued a severe thunderstorm warning for Monroe and Jefferson in Illinois, Missouri, which was in force until 11:30 p.m. local time on September 20. It was the 258th severe thunderstorm warning the NWS office in St Louis issued in 2026. Illinois had 16 severe thunderstorm warnings in September 2026, against 24 in an average September of 2008-2025 (Illinois's severe thunderstorm warnings by year).
ExpiredWarning
In force for 43 minutes; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, St Louis MO
- Area
- Monroe and Jefferson
- State
- Illinois
- Level
- Warning
- Issued
- 10:47 p.m. CDT, September 20, 2026
- Expires
- 11:30 p.m. CDT, September 20, 2026
- CAP severity, certainty, urgency
- Severe, Observed, Immediate
- VTEC event
- KLSX SV.W 0258
- 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
SVRLSX The National Weather Service in St Louis has issued a * Severe Thunderstorm Warning for... Northwestern Monroe County in southwestern Illinois... Northeastern Jefferson County in east central Missouri... * Until 1130 PM CDT. * At 1047 PM CDT, a severe thunderstorm was located over Horine, or over Pevely, moving east at 20 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... Festus, Antonia, Horine, Crystal City, Pevely, Herculaneum, Barnhart, Imperial, Harrisonville, Kimmswick, Valmeyer, Monroe City, Fountain, Madonnaville, Maeystown, Foster Pond, Waterloo and Columbia. This includes the following State Parks... Illinois Caverns State Natural Area, Mastodon Historic Site and Gov. Dunklin's Grave Historic Site. This includes Interstate 55 in Missouri between exits 175 and 187.
What the agency told people to do
Seek shelter inside a well-built structure and stay away from windows. This storm is capable of producing damaging winds and large hail.
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.