Alert archive / Illinois / Flash Flood Warnings in 2010

Flash Flood Warning 23, NWS Chicago, IL

July 23, 20104 counties in Illinois

NWS Chicago, IL issued this flash flood warning at Jul 23, 2010, 4:17 AM CDT for 4 counties in 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: Jul 23, 2010, 4:17 AM CDT (09:17 UTC)
Expired: Jul 23, 2010, 10:15 AM CDT
In force: 6 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

Counties Boone County, IL, DeKalb County, IL, Ogle County, IL, Winnebago County, IL

The radar

The Chicago radar (KLOT), 98 km from the middle of the area, began a volume at 09:19 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, 9.3 hours before the alert went out and 136 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: 2664 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 1076 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 125 m²/s²
0-3 km storm-relative helicity: 267 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 9.9

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 23, 3:26 AM CDT, 51 minutes earlier.

Area forecast discussion, Jul 23, 3:26 AM CDT, 51 minutes before

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Hazardous weather outlook, Jul 22, 8:42 PM CDT, 7 hours 35 minutes before

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In the hours before

Local storm report, Jul 22, 10:52 PM CDT, 5 hours 25 minutes before

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Local storm report, Jul 22, 11:16 PM CDT, 5 hours 1 minute before

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Local storm report, Jul 22, 11:41 PM CDT, 4 hours 36 minutes before

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Local storm report, Jul 23, 12:02 AM CDT, 4 hours 15 minutes before

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Local storm report, Jul 23, 12:19 AM CDT, 3 hours 58 minutes before

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Local storm report, Jul 23, 1:19 AM CDT, 2 hours 58 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 22, 9:21 PM CDT	Severe Thunderstorm Warning	LOT	Winnebago	54 min
Jul 22, 9:40 PM CDT	Special Marine Warning	LOT		95 min
Jul 22, 9:48 PM CDT	Severe Thunderstorm Warning	LOT	Boone, McHenry, Winnebago	57 min
Jul 22, 10:21 PM CDT	Tornado Warning	LOT	Lake, McHenry	39 min
Jul 22, 10:30 PM CDT	Special Marine Warning	LOT		2 hr
Jul 22, 10:56 PM CDT	Tornado Warning	LOT	Lake	34 min
Jul 22, 11:10 PM CDT	Areal Flood Advisory	LOT	Boone, Lake, McHenry, Winnebago	8 hr
Jul 22, 11:47 PM CDT	Severe Thunderstorm Warning	LOT	Boone, DeKalb, Ogle, Winnebago	30 min
Jul 23, 12:22 AM CDT	Special Marine Warning	LOT		89 min
Jul 23, 1:56 AM CDT	Areal Flood Advisory	LOT	DeKalb, Kane, Ogle	5 hr
Jul 23, 4:35 AM CDT	Flash Flood Watch	LOT	Boone, DeKalb, DuPage, Grundy, Kane, Kendall and 6 more	31 hr
Jul 23, 9:30 AM CDT	River Flood Advisory	LOT	Kane, McHenry	13 hr
Jul 23, 9:57 AM CDT	Small Craft Advisory	LOT		9 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Kane, Kendall	12 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Winnebago	12 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Winnebago	12 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Ogle	12 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Lake	12 hr
Jul 23, 10:00 AM CDT	River Flood Advisory	LOT	Winnebago	12 hr
Jul 23, 10:06 AM CDT	Areal Flood Advisory	LOT	Boone, DeKalb, Ogle, Winnebago	6 hr
Jul 23, 4:28 PM CDT	Special Weather Statement	LOT	LaSalle	62 min
Jul 23, 4:57 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, LaSalle, Livingston	48 min
Jul 23, 5:28 PM CDT	Special Weather Statement	LOT	DeKalb, Kane, Kendall	32 min
Jul 23, 5:39 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, DuPage, Grundy, Kane, Kendall, LaSalle and 1 more	55 min
Jul 23, 5:45 PM CDT	Special Weather Statement	LOT	Cook, DuPage, Kane	60 min
Jul 23, 5:51 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Grundy, Iroquois, Kankakee, Livingston, Will	54 min
Jul 23, 6:04 PM CDT	Areal Flood Advisory	LOT	Cook, DeKalb, DuPage, Grundy, Kane, Kendall and 2 more	3 hr
Jul 23, 6:06 PM CDT	Special Marine Warning	LOT		84 min
Jul 23, 6:13 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Kankakee, Will	45 min
Jul 23, 6:18 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Kankakee, Livingston	57 min
Jul 23, 6:44 PM CDT	Special Weather Statement	LOT	Cook, Lake	61 min
Jul 23, 6:53 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Lake, Newton, Porter	51 min

Nearby

Flash Flood Warnings in Illinois, 2010 Every flash flood warning in 2010

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.