Alert archive / Illinois / Flash Flood Warnings in 2023

Flash Flood Warning 10, NWS Chicago, IL

July 28, 2023DuPage County, Kane County, Illinois

NWS Chicago, IL issued this flash flood warning at Jul 28, 2023, 8:24 PM CDT for DuPage County, Kane County, Illinois. It was in force for 4 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 28, 2023, 8:24 PM CDT (01:24 UTC)
Expired: Jul 29, 2023, 12:49 AM CDT
In force: 4 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

Counties DuPage County, IL, Kane County, IL

The radar

The Chicago radar (KLOT), 35 km from the middle of the area, began a volume at 01:24 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, 1.4 hours before the alert went out and 189 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: 3767 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1322 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 6.0

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 Jul 28, 6:34 PM CDT, 1 hour 50 minutes earlier.

Area forecast discussion, Jul 28, 6:34 PM CDT, 1 hour 50 minutes before

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Hazardous weather outlook, Jul 28, 4:03 PM CDT, 4 hours 21 minutes before

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In the hours before

Special weather statement, Jul 28, 7:25 PM CDT, 59 minutes before

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Local storm report, Jul 28, 7:58 PM CDT, 26 minutes before

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Local storm report, Jul 28, 8:00 PM CDT, 24 minutes before

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Local storm report, Jul 28, 8:03 PM CDT, 21 minutes before

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Local storm report, Jul 28, 8:09 PM CDT, 15 minutes before

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Local storm report, Jul 28, 8:17 PM CDT, 7 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
Jul 28, 7:25 PM CDT	Special Weather Statement	LOT	DuPage, Kane	35 min
Jul 28, 7:27 PM CDT	Severe Thunderstorm Warning	LOT	DuPage	33 min
Jul 28, 7:36 PM CDT	Flood Watch	LOT	Boone, Cook, DeKalb, DuPage, Grundy, Kane and 9 more	5 hr
Jul 28, 7:37 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane	38 min
Jul 28, 8:03 PM CDT	Areal Flood Advisory	LOT	DuPage, Kane	21 min
Jul 28, 8:10 PM CDT	Severe Thunderstorm Warning	LOT	Winnebago	50 min
Jul 28, 8:12 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane	48 min
Jul 28, 8:30 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Ogle, Winnebago	45 min
Jul 28, 8:32 PM CDT	Special Weather Statement	LOT	Lake	43 min
Jul 28, 8:41 PM CDT	Areal Flood Advisory	LOT	Boone, McHenry, Winnebago	4 hr
Jul 28, 8:45 PM CDT	Special Weather Statement	LOT	DuPage	45 min
Jul 28, 8:47 PM CDT	Areal Flood Advisory	LOT	Cook, Kane	4 hr
Jul 28, 8:54 PM CDT	Special Weather Statement	LOT	Cook, DuPage, Lake	66 min
Jul 28, 8:56 PM CDT	Severe Thunderstorm Warning	LOT	Winnebago	49 min
Jul 28, 9:01 PM CDT	Special Marine Warning	LOT		119 min
Jul 28, 9:04 PM CDT	Areal Flood Advisory	LOT	Lake	4 hr
Jul 28, 9:04 PM CDT	Severe Thunderstorm Warning	LOT	Lake	41 min
Jul 28, 9:16 PM CDT	Flash Flood Warning	LOT	Boone, Winnebago	3 hr
Jul 28, 9:17 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Boone, McHenry	43 min
Jul 28, 9:28 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Ogle, Winnebago	47 min
Jul 28, 9:41 PM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle	66 min
Jul 28, 9:47 PM CDT	Special Marine Warning	LOT		43 min
Jul 28, 9:55 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane, McHenry	50 min
Jul 28, 10:03 PM CDT	Areal Flood Advisory	LOT	DeKalb	3 hr
Jul 28, 10:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	DeKalb, LaSalle	65 min
Jul 28, 10:23 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kane	67 min
Jul 28, 10:26 PM CDT	Severe Thunderstorm Warning	LOT	Kendall	51 min
Jul 28, 10:28 PM CDT	Special Marine Warning	LOT		2 hr
Jul 28, 10:39 PM CDT	Severe Thunderstorm Warning	LOT	Grundy	50 min
Jul 28, 10:45 PM CDT	Severe Thunderstorm Warning Destructive damage threat	LOT	Kendall, Will	45 min
Jul 28, 10:55 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	50 min
Jul 28, 11:01 PM CDT	Flash Flood Warning	LOT	Cook	108 min
Jul 28, 11:06 PM CDT	Severe Thunderstorm Warning	LOT	Kankakee	54 min
Jul 28, 11:11 PM CDT	Special Marine Warning	LOT		66 min
Jul 28, 11:24 PM CDT	Tornado Warning Tornado observed	LOT	Kankakee, Will	21 min
Jul 29, 12:26 AM CDT	Special Marine Warning	LOT		79 min
Jul 29, 3:25 AM CDT	Beach Hazards Statement	LOT	Cook, Lake	16 hr
Jul 29, 3:26 AM CDT	Small Craft Advisory	LOT		16 hr
Jul 28, 11:31 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Lake, Newton	44 min
Jul 28, 11:43 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Jasper, Porter	62 min

Nearby

Flash Flood Warnings in Illinois, 2023 Every flash flood warning in 2023

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.