Alert archive / Illinois / Flash Flood Warnings in 2014

Flash Flood Warning 25, NWS Chicago, IL

August 22, 2014Grundy County, LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this flash flood warning at Aug 22, 2014, 5:10 AM CDT for Grundy County, LaSalle County, 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: Aug 22, 2014, 5:10 AM CDT (10:10 UTC)
Expired: Aug 22, 2014, 11:00 AM CDT
In force: 6 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

Counties Grundy County, IL, LaSalle County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 66 km from the middle of the area, began a volume at 10:13 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, 10.2 hours before the alert went out and 114 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: 2483 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 1018 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 6.5

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 Aug 22, 4:15 AM CDT, 55 minutes earlier.

Area forecast discussion, Aug 22, 4:15 AM CDT, 55 minutes before

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Hazardous weather outlook, Aug 22, 4:47 AM CDT, 23 minutes before

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In the hours before

Local storm report, Aug 22, 3:46 AM CDT, 1 hour 24 minutes before

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Local storm report, Aug 22, 4:16 AM CDT, 54 minutes before

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Local storm report, Aug 22, 4:24 AM CDT, 46 minutes before

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Local storm report, Aug 22, 4:32 AM CDT, 38 minutes before

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Local storm report, Aug 22, 4:35 AM CDT, 35 minutes before

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Local storm report, Aug 22, 4:38 AM CDT, 32 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
Aug 22, 12:25 AM CDT	Areal Flood Advisory	LOT	DeKalb, LaSalle, Lee	6 hr
Aug 22, 1:13 AM CDT	Areal Flood Advisory	LOT	Cook, DuPage	6 hr
Aug 22, 1:24 AM CDT	Dense Fog Advisory	LOT	Lake, McHenry	9 hr
Aug 22, 2:06 AM CDT	Areal Flood Advisory	LOT	Ford, Grundy, Iroquois, Kankakee, LaSalle, Livingston	6 hr
Aug 22, 2:20 AM CDT	Flash Flood Warning	LOT	Cook, DuPage	6 hr
Aug 22, 3:26 AM CDT	Areal Flood Advisory	LOT	Iroquois	6 hr
Aug 22, 7:51 AM CDT	Areal Flood Advisory	LOT	Ford, Iroquois, LaSalle, Livingston	6 hr
Aug 22, 8:15 AM CDT	River Flood Warning	LOT	Cook	12 hr
Aug 22, 8:15 AM CDT	River Flood Warning	LOT	DuPage	11 hr
Aug 22, 8:22 AM CDT	River Flood Advisory	LOT	Kane, Kendall	34 hr
Aug 22, 8:28 AM CDT	Areal Flood Warning	LOT	Cook, DuPage	34 hr
Aug 22, 10:56 AM CDT	Areal Flood Warning	LOT	Grundy, LaSalle, Livingston	6 hr
Aug 22, 1:41 AM CDT	Flash Flood Warning	LOT	Lake, Porter	6 hr
Aug 22, 7:28 AM CDT	Areal Flood Warning	LOT	Lake, Porter	35 hr
Aug 22, 9:29 AM CDT	Areal Flood Advisory	LOT	Jasper	6 hr

Nearby

Flash Flood Warnings in Illinois, 2014 Every flash flood warning in 2014

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.