Alert archive / Illinois / Flash Flood Warnings in 2026

Flash Flood Warning 5, NWS Chicago, IL

April 3, 2026Livingston County, Illinois

NWS Chicago, IL issued this flash flood warning at Apr 3, 2026, 8:08 PM CDT for Livingston County, Illinois. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 3, 2026, 8:08 PM CDT (01:08 UTC)
Expired: Apr 4, 2026, 2:00 AM CDT
In force: 6 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

County Livingston County, IL

The radar

The Chicago radar (KLOT), 89 km from the middle of the area, began a volume at 01:10 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 00:00Z, 1.1 hours before the alert went out and 83 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: 1147 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1065 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 167 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Apr 3, 6:33 PM CDT, 1 hour 35 minutes earlier.

Area forecast discussion, Apr 3, 6:33 PM CDT, 1 hour 35 minutes before

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Hazardous weather outlook, Apr 3, 4:37 PM CDT, 3 hours 31 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
Apr 3, 9:17 PM CDT	River Flood Warning	LOT	Lake	8 days
Apr 3, 9:46 PM CDT	Flash Flood Warning	LOT	Grundy, Kankakee, Livingston, Will	4 hr
Apr 3, 10:07 PM CDT	Small Craft Advisory	LOT		42 hr
Apr 3, 10:12 PM CDT	River Flood Warning	LOT	LaSalle	4 days
Apr 3, 11:24 PM CDT	Areal Flood Advisory	LOT	Cook	3 hr
Apr 4, 1:59 AM CDT	Areal Flood Warning	LOT	Cook, Grundy, Kankakee, LaSalle, Livingston, Will	8 hr
Apr 4, 6:37 AM CDT	River Flood Warning	LOT	Cook	24 hr
Apr 4, 11:29 AM CDT	River Flood Watch	LOT	Cook, Lake	57 hr
Apr 4, 11:29 AM CDT	River Flood Warning	LOT	Lake	8 days
Apr 4, 2:30 PM CDT	River Flood Warning	LOT	Boone, Winnebago	23 hr
Apr 3, 9:23 PM CDT	River Flood Warning	LOT	Lake, Newton	11 days
Apr 4, 5:43 AM CDT	River Flood Warning	LOT	Jasper, Porter	9 days

Nearby

Flash Flood Warnings in Illinois, 2026 Every flash flood 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.