Alert archive / Illinois / Flash Flood Warnings in 2026
Flash Flood Warning 20, NWS Chicago, IL
NWS Chicago, IL issued this flash flood warning at Jul 2, 2026, 11:17 PM CDT for DuPage County, Kane County, Kendall County, Illinois. It was in force for 3 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
- Jul 2, 2026, 11:17 PM CDT (04:17 UTC)
- Expired
- Jul 3, 2026, 2:15 AM CDT
- In force
- 3 hr
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Flood severity
- None
Counties DuPage County, IL, Kane County, IL, Kendall County, IL
The radar
The Chicago radar (KLOT), 28 km from the middle of the area, began a volume at 04:17 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
Davenport, (KDVN), launched 00:00Z, 4.3 hours before the alert went out and 182 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
- 1944 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 1423 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 104 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 4.1
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 Jul 2, 6:30 PM CDT, 4 hours 47 minutes earlier.
Area forecast discussion, Jul 2, 6:30 PM CDT, 4 hours 47 minutes before
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</html>Hazardous weather outlook, Jul 2, 3:24 PM CDT, 7 hours 53 minutes before
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Local storm report, Jul 2, 9:52 PM CDT, 1 hour 25 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 |
|---|---|---|---|---|
| Jul 2, 8:35 PM CDT | Special Marine Warning | LOT | 85 min | |
| Jul 2, 8:58 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Lake | 3 hr |
| Jul 2, 9:44 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage | 46 min |
| Jul 2, 10:06 PM CDT | Special Marine Warning | LOT | 3 hr | |
| Jul 2, 10:17 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage | 3 hr |
| Jul 2, 10:26 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage | 64 min |
| Jul 2, 10:51 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Kane, Kendall, Will | 3 hr |
| Jul 2, 11:15 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Kane, Kendall | 60 min |
| Jul 3, 12:00 AM CDT | Areal Flood Advisory | LOT | DeKalb, Kane | 2 hr |
| Jul 3, 12:16 AM CDT | Flash Flood Warning | LOT | DeKalb, Kane, Kendall | 114 min |
| Jul 3, 1:22 AM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Kane, Kendall, Will | 7 hr |
| Jul 3, 1:35 AM CDT | Special Marine Warning | LOT | 52 min | |
| Jul 3, 2:04 AM CDT | Areal Flood Warning | LOT | DeKalb, DuPage, Kane, Kendall, Will | 6 hr |
| Jul 3, 7:59 AM CDT | Areal Flood Warning | LOT | Cook, DuPage | 10 hr |
| Jul 3, 8:01 AM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Kane, Kendall, Will | 3 hr |
| Jul 3, 8:59 AM CDT | Heat Advisory | LOT | Ford, Iroquois, Kankakee, Livingston | 10 hr |
| Jul 3, 10:56 AM CDT | Severe Thunderstorm Warning | LOT | Ogle | 64 min |
| Jul 3, 11:14 AM CDT | Severe Thunderstorm Warning | LOT | Boone, Winnebago | 61 min |
| Jul 3, 12:21 PM CDT | Severe Thunderstorm Warning | LOT | DeKalb, LaSalle, Lee | 54 min |
| Jul 3, 12:42 PM CDT | Severe Thunderstorm Warning | LOT | Cook, DuPage, Kane | 63 min |
| Jul 3, 12:44 PM CDT | Severe Thunderstorm Warning | LOT | Kendall | 46 min |
| Jul 3, 12:48 PM CDT | Special Marine Warning | LOT | 117 min | |
| Jul 3, 1:05 PM CDT | Severe Thunderstorm Warning | LOT | Cook | 40 min |
| Jul 3, 2:02 PM CDT | Severe Thunderstorm Warning | LOT | Grundy, Kendall, Will | 43 min |
| Jul 3, 2:11 PM CDT | Areal Flood Advisory | LOT | Cook | 3 hr |
| Jul 3, 2:27 PM CDT | Severe Thunderstorm Warning | LOT | Cook | 48 min |
| Jul 3, 2:40 PM CDT | Special Marine Warning | LOT | 60 min | |
| Jul 3, 2:40 PM CDT | Special Marine Warning | LOT | 60 min | |
| Jul 3, 2:40 PM CDT | Severe Thunderstorm Warning | LOT | Will | 59 min |
| Jul 3, 4:26 PM CDT | Severe Thunderstorm Warning | LOT | Will | 49 min |
| Jul 3, 6:35 PM CDT | Tornado Warning | LOT | Ogle, Winnebago | 25 min |
| Jul 3, 6:51 PM CDT | Severe Thunderstorm Warning | LOT | Ogle, Winnebago | 54 min |
Nearby
Flash Flood Warnings in Illinois, 2026Every 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.