Alert archive / Illinois / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 39, NWS Chicago, IL

March 30, 20265 counties in Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Mar 30, 2026, 10:42 PM CDT for 5 counties in Illinois. It was in force for 26 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: Mar 30, 2026, 10:42 PM CDT (03:42 UTC)
Expired: Mar 30, 2026, 11:08 PM CDT
In force: 26 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Boone County, IL, DeKalb County, IL, Kane County, IL, McHenry County, IL, Ogle County, IL

The radar

The Chicago radar (KLOT), 79 km from the middle of the area, began a volume at 03:45 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
Mar 30, 9:21 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.7 hours before the alert went out and 154 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1078 J/kg
Mixed-layer CIN: -286 J/kg
Mixed-layer LCL: 2123 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 352 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

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 Mar 30, 6:32 PM CDT, 4 hours 10 minutes earlier.

Area forecast discussion, Mar 30, 6:32 PM CDT, 4 hours 10 minutes before

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Hazardous weather outlook, Mar 30, 2:18 PM CDT, 8 hours 24 minutes before

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In the hours before

Local storm report, Mar 30, 10:16 PM CDT, 26 minutes before

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Local storm report, Mar 30, 10:17 PM CDT, 25 minutes before

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Local storm report, Mar 30, 10:18 PM CDT, 24 minutes before

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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 30, 9:28 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane, Kendall	47 min
Mar 30, 9:55 PM CDT	Special Marine Warning	LOT		80 min
Mar 30, 10:04 PM CDT	Special Marine Warning	LOT		116 min
Mar 30, 10:04 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane, Kendall, Will	71 min
Mar 30, 10:19 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane	56 min
Mar 30, 11:03 PM CDT	Severe Thunderstorm Warning	LOT	Cook	31 min
Mar 30, 11:06 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	39 min
Mar 30, 11:23 PM CDT	Special Marine Warning	LOT		37 min
Mar 31, 8:00 AM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Lee	45 min
Mar 31, 8:41 AM CDT	Severe Thunderstorm Warning	LOT	LaSalle	49 min
Mar 31, 9:09 AM CDT	Severe Thunderstorm Warning	LOT	Grundy, Kankakee, Kendall, Will	52 min
Mar 31, 9:29 AM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, Kankakee, Will	61 min
Mar 31, 9:33 AM CDT	Areal Flood Advisory	LOT	Cook, Will	4 hr
Mar 31, 9:47 AM CDT	Severe Thunderstorm Warning	LOT	Livingston	49 min
Mar 31, 9:59 AM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle	46 min
Mar 31, 10:23 AM CDT	Severe Thunderstorm Warning	LOT	Ogle	32 min
Mar 31, 11:30 AM CDT	Special Marine Warning	LOT		57 min
Mar 31, 2:53 PM CDT	Areal Flood Advisory	LOT	Kendall, Will	3 hr
Mar 31, 4:03 PM CDT	Special Marine Warning	LOT		57 min
Mar 31, 4:06 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	23 min
Mar 31, 4:12 PM CDT	Areal Flood Advisory	LOT	Cook, Will	3 hr
Mar 31, 9:55 AM CDT	Severe Thunderstorm Warning	LOT	Lake	50 min
Mar 31, 3:56 PM CDT	Severe Thunderstorm Warning	LOT	Porter	34 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2026 Every 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.