Alert archive / Illinois / Severe Thunderstorm Warnings in 2025
Severe Thunderstorm Warning 101, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Aug 16, 2025, 2:43 PM CDT for Boone County, McHenry County, Winnebago County, Illinois. It was in force for 47 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 16, 2025, 2:43 PM CDT (19:43 UTC)
- Expired
- Aug 16, 2025, 3:30 PM CDT
- In force
- 47 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
Counties Boone County, IL, McHenry County, IL, Winnebago County, IL
The radar
The Milwaukee radar (KMKX), 74 km from the middle of the area, began a volume at 19:44 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 16, 1:56 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 7.7 hours before the alert went out and 243 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
- 1421 J/kg
- Mixed-layer CIN
- -116 J/kg
- Mixed-layer LCL
- 1426 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.7
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 Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 16, 2:15 PM CDT, 28 minutes earlier.
Area forecast discussion, Aug 16, 2:15 PM CDT, 28 minutes before
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</html>Hazardous weather outlook, Aug 16, 4:00 AM CDT, 10 hours 43 minutes before
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</html>The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 3:29 AM CDT | Heat Advisory | LOT | Ford, Grundy, Iroquois, Kankakee, Kendall, LaSalle and 3 more | 17 hr |
| Aug 16, 3:04 PM CDT | Severe Thunderstorm Warning | LOT | Boone, Winnebago | 40 min |
| Aug 16, 3:10 PM CDT | Special Marine Warning | LOT | 2 hr | |
| Aug 16, 3:21 PM CDT | Severe Thunderstorm Warning | LOT | Lake, McHenry | 54 min |
| Aug 16, 3:36 PM CDT | Severe Thunderstorm Warning | LOT | Boone, McHenry, Winnebago | 39 min |
| Aug 16, 3:48 PM CDT | Special Marine Warning | LOT | 117 min | |
| Aug 16, 3:48 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DeKalb, Kane, Lake, McHenry, Ogle | 57 min |
| Aug 16, 4:10 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage | 50 min |
| Aug 16, 4:21 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Kane | 54 min |
| Aug 16, 4:23 PM CDT | Dust Storm Advisory | LOT | DeKalb, DuPage, Kane, Kendall, LaSalle, Lee and 1 more | 67 min |
| Aug 16, 5:00 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kane, Kendall, Will | 45 min |
| Aug 16, 5:11 PM CDT | Flash Flood Warning | LOT | DuPage | 2 hr |
| Aug 16, 5:34 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Will | 3 hr |
| Aug 16, 5:38 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Kankakee, Will | 52 min |
| Aug 16, 5:59 PM CDT | Special Marine Warning | LOT | 2 hr | |
| Aug 16, 6:16 PM CDT | Special Weather Statement | LOT | Kankakee | 44 min |
| Aug 16, 6:45 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois, Kankakee | 45 min |
| Aug 16, 4:49 PM CDT | Severe Thunderstorm Warning | LOT | Lake | 26 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 2025Every severe thunderstorm warning in 2025
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.