Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 161, NWS Chicago, IL

August 13, 2011Grundy County, Will County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Aug 13, 2011, 2:54 PM CDT for Grundy County, Will County, Illinois. It was in force for 41 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 13, 2011, 2:54 PM CDT (19:54 UTC)
Expired: Aug 13, 2011, 3:35 PM CDT
In force: 41 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Grundy County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 28 km from the middle of the area, began a volume at 19:54 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 13, 12:12 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.9 hours before the alert went out and 139 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 7333 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 88 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 13, 1:27 PM CDT, 1 hour 27 minutes earlier.

Area forecast discussion, Aug 13, 1:27 PM CDT, 1 hour 27 minutes before

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Hazardous weather outlook, Aug 13, 11:50 AM CDT, 3 hours 4 minutes before

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In the hours before

Local storm report, Aug 13, 2:28 PM CDT, 26 minutes before

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Local storm report, Aug 13, 2:33 PM CDT, 21 minutes before

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Local storm report, Aug 13, 2:44 PM CDT, 10 minutes before

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Local storm report, Aug 13, 2:48 PM CDT, 6 minutes before

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Local storm report, Aug 13, 2:50 PM CDT, 4 minutes before

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Local storm report, Aug 13, 2:54 PM CDT, 0 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 12, 7:03 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Ogle	57 min
Aug 13, 3:31 AM CDT	Small Craft Advisory	LOT		54 hr
Aug 13, 10:46 AM CDT	Severe Thunderstorm Warning	LOT	Winnebago	59 min
Aug 13, 11:29 AM CDT	Severe Thunderstorm Warning	LOT	Boone, DeKalb, McHenry, Ogle, Winnebago	46 min
Aug 13, 12:00 PM CDT	Special Marine Warning	LOT		3 hr
Aug 13, 12:19 PM CDT	Special Weather Statement	LOT	DeKalb, Kane, McHenry	56 min
Aug 13, 12:55 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Lake, McHenry	50 min
Aug 13, 1:52 PM CDT	Special Weather Statement	LOT	Cook	38 min
Aug 13, 1:54 PM CDT	Special Weather Statement	LOT	Ogle	36 min
Aug 13, 2:02 PM CDT	Special Marine Warning	LOT		88 min
Aug 13, 2:12 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	63 min
Aug 13, 2:23 PM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle	67 min
Aug 13, 2:31 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle	34 min
Aug 13, 2:48 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, DuPage, Kane, Kendall, Will	57 min
Aug 13, 3:27 PM CDT	Special Weather Statement	LOT	Grundy	48 min
Aug 13, 3:32 PM CDT	Special Weather Statement	LOT	Livingston	28 min
Aug 13, 3:35 PM CDT	Special Weather Statement	LOT	Livingston	25 min
Aug 13, 3:44 PM CDT	Special Weather Statement	LOT	Kane, Kendall	31 min
Aug 13, 4:01 PM CDT	Special Weather Statement	LOT	Livingston	44 min
Aug 13, 4:14 PM CDT	Special Weather Statement	LOT	DuPage, Kane, Kendall	46 min
Aug 13, 4:19 PM CDT	Special Weather Statement	LOT	Iroquois	41 min
Aug 13, 4:24 PM CDT	Severe Thunderstorm Warning	LOT	Iroquois	66 min
Aug 13, 4:44 PM CDT	Rip Current Statement	LOT	Lake	41 hr
Aug 13, 5:17 PM CDT	Areal Flood Advisory	LOT	Boone, DeKalb, McHenry, Ogle, Winnebago	2 hr
Aug 13, 3:49 PM CDT	Special Weather Statement	LOT	Lake	56 min
Aug 13, 4:30 PM CDT	Special Weather Statement	LOT	Lake, Porter	45 min
Aug 13, 4:47 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Lake, Porter	29 min
Aug 13, 5:25 PM CDT	Severe Thunderstorm Warning	LOT	Benton	50 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2011 Every severe thunderstorm warning in 2011

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.