Alert archive / Illinois / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 343, NWS Lincoln, IL
NWS Lincoln, IL issued this severe thunderstorm warning at Aug 11, 2026, 2:50 PM CDT for DeWitt County, McLean County, Piatt County, Illinois. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Aug 11, 2026, 2:50 PM CDT (19:50 UTC)
- Expired
- Aug 11, 2026, 3:30 PM CDT
- In force
- 40 min
- Issued by
- NWS Lincoln, IL
- Area
- Storm-based polygon
- Hail
- 0.88 in
- Wind
- 60.0 mph
Counties DeWitt County, IL, McLean County, IL, Piatt County, IL
The radar
The Lincoln radar (KILX), 48 km from the middle of the area, began a volume at 19:53 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 7.8 hours before the alert went out and 17 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 2617 J/kg
- Mixed-layer CIN
- -144 J/kg
- Mixed-layer LCL
- 1547 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 142 m²/s²
- 0-3 km storm-relative helicity
- 140 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.5
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Lincoln, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 2:45 PM CDT, 5 minutes earlier.
Area forecast discussion, Aug 11, 2:45 PM CDT, 5 minutes before
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</html>Hazardous weather outlook, Aug 11, 11:32 AM CDT, 3 hours 18 minutes before
Hazardous Weather Outlook National Weather Service Lincoln IL 1132 AM CDT Tue Aug 11 2026 ILZ027>031-036>038-040>042-047>051-121100- Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler- Mason-Logan-Cass-Menard-Scott-Morgan-Sangamon- 1132 AM CDT Tue Aug 11 2026 This Hazardous Weather Outlook is for central Illinois and west central Illinois, mainly along and west of I-55. .DAY ONE...This afternoon and tonight. Scattered thunderstorms are expected into the evening hours, mainly along and north of I-74. A few of these may contain damaging winds, though the severe weather threat is not as high as earlier. Heat index values of 100 to 105 degrees are expected today, primarily south of I-74. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Heat indices of 95 to 105 degrees are expected Wednesday afternoon. Daily chances for thunderstorms and heavy rain exist through the weekend. Some of these storms could be severe through at least Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed through sunset. ILZ043>046-052>057-061>063-066>068-071>073-121100- De Witt-Piatt-Champaign-Vermilion-Christian-Macon-Moultrie-Douglas- Coles-Edgar-Shelby-Cumberland-Clark-Effingham-Jasper-Crawford-Clay- Richland-Lawrence- 1132 AM CDT Tue Aug 11 2026 This Hazardous Weather Outlook is for east central Illinois and southeast Illinois. .DAY ONE...This afternoon and tonight. Scattered thunderstorms are expected to develop over east central Illinois by mid afternoon, with a risk developing in southeast Illinois by early evening. These storms may be severe, with potential for wind gusts in excess of 70 mph. Outside of the storms, heat index readings of 100 to 105 degrees are likely this afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Heat indices of 95 to 105 degrees are expected Wednesday and Thursday afternoons, primarily south of I-70. Daily chances for thunderstorms and heavy rain exist through the weekend. Some of these storms could be severe through at least Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed mid to late afternoon north of I-70, and early this evening south of I-70. Geelhart
The office that day
Everything else NWS Lincoln, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 9:44 AM CDT | Severe Thunderstorm Warning | ILX | Marshall | 46 min |
| Aug 11, 1:57 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Vermilion | 63 min |
| Aug 11, 3:17 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Piatt | 43 min |
| Aug 11, 3:25 PM CDT | Tornado Warning | ILX | Champaign, Douglas, Piatt | 50 min |
| Aug 11, 3:52 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Douglas, Edgar, Vermilion | 53 min |
| Aug 11, 4:22 PM CDT | Severe Thunderstorm Warning | ILX | Clark, Edgar | 38 min |
| Aug 11, 5:30 PM CDT | Severe Thunderstorm Warning | ILX | Clark | 45 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 2026Every severe thunderstorm warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.