Alert archive / Illinois / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 75, NWS Chicago, IL

May 22, 2004Grundy County, Will County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 22, 2004, 12:36 PM CDT for Grundy County, Will County, Illinois. 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: May 22, 2004, 12:36 PM CDT (17:36 UTC)
Expired: May 22, 2004, 1:15 PM CDT
In force: 39 min
Issued by: NWS Chicago, IL
Area: Counties, with a storm outline in the text

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 17:37 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
May 22, 11:35 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 5.6 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: 454 J/kg
Mixed-layer CIN: -171 J/kg
Mixed-layer LCL: 1064 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 248 m²/s²
0-3 km storm-relative helicity: 281 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

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 May 22, 6:45 AM CDT, 5 hours 51 minutes earlier.

Area forecast discussion, May 22, 6:45 AM CDT, 5 hours 51 minutes before

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Hazardous weather outlook, May 22, 11:00 AM CDT, 1 hour 36 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
May 21, 7:00 PM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle, Winnebago	60 min
May 21, 7:09 PM CDT	Flash Flood Warning	LOT	Lake, McHenry	3 hr
May 21, 7:12 PM CDT	Special Marine Warning	LOT		108 min
May 21, 7:12 PM CDT	Special Marine Warning	LOT		108 min
May 21, 7:12 PM CDT	Special Marine Warning	LOT		108 min
May 21, 7:12 PM CDT	Special Marine Warning	LOT		108 min
May 21, 7:13 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane	47 min
May 21, 7:23 PM CDT	Flash Flood Warning	LOT	Cook, DeKalb, DuPage, Kane, Lee, Ogle	3 hr
May 21, 7:59 PM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle, Winnebago	61 min
May 21, 8:01 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane	59 min
May 21, 8:03 PM CDT	Tornado Warning	LOT	DeKalb	27 min
May 21, 8:22 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	53 min
May 21, 8:35 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	40 min
May 21, 8:58 PM CDT	Special Marine Warning	LOT		2 hr
May 21, 8:58 PM CDT	Special Marine Warning	LOT		2 hr
May 21, 8:58 PM CDT	Special Marine Warning	LOT		2 hr
May 21, 9:10 PM CDT	Severe Thunderstorm Warning	LOT	Kane, Kendall	50 min
May 21, 11:47 PM CDT	Special Marine Warning	LOT		118 min
May 21, 11:47 PM CDT	Special Marine Warning	LOT		118 min
May 22, 12:22 AM CDT	Severe Thunderstorm Warning	LOT	Lake	23 min
May 22, 12:36 AM CDT	Severe Thunderstorm Warning	LOT	McHenry	54 min
May 22, 1:33 AM CDT	Special Marine Warning	LOT		117 min
May 22, 1:33 AM CDT	Special Marine Warning	LOT		117 min
May 22, 1:33 AM CDT	Special Marine Warning	LOT		117 min
May 22, 1:40 AM CDT	Severe Thunderstorm Warning	LOT	Cook	50 min
May 22, 2:16 AM CDT	Severe Thunderstorm Warning	LOT	DeKalb	44 min
May 22, 4:22 AM CDT	Severe Thunderstorm Warning	LOT	Lee, Ogle, Winnebago	83 min
May 22, 12:42 PM CDT	Special Marine Warning	LOT		93 min
May 22, 12:42 PM CDT	Special Marine Warning	LOT		93 min
May 22, 12:42 PM CDT	Special Marine Warning	LOT		93 min
May 22, 1:48 PM CDT	Severe Thunderstorm Warning	LOT	Iroquois	42 min
May 22, 6:23 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, Will	37 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2004 Every severe thunderstorm warning in 2004

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.