Alert archive / Illinois / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 151, NWS Chicago, IL

August 24, 2007Iroquois County, Illinois; Benton County, Indiana

NWS Chicago, IL issued this severe thunderstorm warning at Aug 24, 2007, 2:51 PM CDT for Iroquois County, Illinois; Benton County, Indiana. It was in force for 39 min. 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 24, 2007, 2:51 PM CDT (19:51 UTC)
Expired: Aug 24, 2007, 3:30 PM CDT
In force: 39 min
Issued by: NWS Chicago, IL
Area: Counties, with a storm outline in the text

Counties Iroquois County, IL, Benton County, IN

The radar

The Chicago radar (KLOT), 112 km from the middle of the area, began a volume at 19:52 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 12:00Z, 7.9 hours before the alert went out and 105 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: 1385 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 871 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 106 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Aug 24, 1:00 PM CDT, 1 hour 51 minutes earlier.

Area forecast discussion, Aug 24, 1:00 PM CDT, 1 hour 51 minutes before

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Hazardous weather outlook, Aug 24, 12:55 PM CDT, 1 hour 56 minutes before

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In the hours before

Local storm report, Aug 24, 9:13 AM CDT, 5 hours 38 minutes before

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Local storm report, Aug 24, 9:39 AM CDT, 5 hours 12 minutes before

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Local storm report, Aug 24, 11:21 AM CDT, 3 hours 30 minutes before

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Local storm report, Aug 24, 11:24 AM CDT, 3 hours 27 minutes before

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Local storm report, Aug 24, 2:08 PM CDT, 43 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 23, 7:08 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	82 min
Aug 23, 7:18 PM CDT	Flash Flood Warning	LOT	Kankakee	4 hr
Aug 23, 7:33 PM CDT	Tornado Warning	LOT	Kankakee	57 min
Aug 23, 7:42 PM CDT	Severe Thunderstorm Warning	LOT	Grundy	30 min
Aug 23, 8:16 PM CDT	Severe Thunderstorm Warning	LOT	Kankakee, Will	65 min
Aug 23, 8:24 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois	58 min
Aug 23, 9:14 PM CDT	River Flood Warning	LOT	LaSalle	5 days
Aug 23, 9:20 PM CDT	Flash Flood Warning	LOT	Cook, DeKalb, DuPage, Grundy, Kane, Kankakee and 6 more	7 hr
Aug 23, 10:45 PM CDT	River Flood Advisory	LOT	Grundy	62 hr
Aug 24, 2:29 AM CDT	River Flood Warning	LOT	Cook	42 hr
Aug 24, 2:46 AM CDT	River Flood Advisory	LOT	Cook	28 hr
Aug 24, 3:58 AM CDT	River Flood Warning	LOT	Kankakee	4 days
Aug 24, 10:49 AM CDT	River Flood Warning	LOT	Grundy	65 hr
Aug 24, 10:49 AM CDT	River Flood Warning	LOT	LaSalle	10 hr
Aug 23, 7:10 PM CDT	Severe Thunderstorm Warning	LOT	Lake, Porter	60 min
Aug 23, 7:46 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Newton	42 min
Aug 23, 8:05 PM CDT	Tornado Warning	LOT	Newton	25 min
Aug 23, 8:47 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Lake, Newton, Porter	48 min
Aug 23, 9:14 PM CDT	River Flood Warning	LOT	Porter	8 days
Aug 23, 9:14 PM CDT	River Flood Warning	LOT	Jasper, Porter	8 days
Aug 23, 10:05 PM CDT	Flash Flood Warning	LOT	Jasper, Newton	6 hr
Aug 23, 10:54 PM CDT	River Flood Warning	LOT	Lake	72 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2007 Severe Thunderstorm Warnings in Indiana, 2007 Every severe thunderstorm warning in 2007

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.