Alert archive / Illinois / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 35, NWS Chicago, IL

April 10, 2017Cook County, Kendall County, Will County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Apr 10, 2017, 12:49 PM CDT for Cook County, Kendall 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: Apr 10, 2017, 12:49 PM CDT (17:49 UTC)
Expired: Apr 10, 2017, 1:30 PM CDT
In force: 41 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Cook County, IL, Kendall County, IL, Will County, IL

The radar

The Chicago radar (KLOT), 7 km from the middle of the area, began a volume at 17:51 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, 5.8 hours before the alert went out and 173 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: 1373 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: -63 m²/s²
0-3 km storm-relative helicity: 3 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 Apr 10, 11:56 AM CDT, 53 minutes earlier.

Area forecast discussion, Apr 10, 11:56 AM CDT, 53 minutes before

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Hazardous weather outlook, Apr 10, 10:31 AM CDT, 2 hours 18 minutes before

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In the hours before

Special weather statement, Apr 10, 6:55 AM CDT, 5 hours 54 minutes before

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Special weather statement, Apr 10, 8:01 AM CDT, 4 hours 48 minutes before

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Local storm report, Apr 10, 8:23 AM CDT, 4 hours 26 minutes before

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Local storm report, Apr 10, 8:45 AM CDT, 4 hours 4 minutes before

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Special weather statement, Apr 10, 12:26 PM CDT, 23 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
Apr 10, 4:38 AM CDT	Special Weather Statement	LOT	McHenry	22 min
Apr 10, 4:47 AM CDT	Special Weather Statement	LOT	DuPage, Kane	43 min
Apr 10, 5:07 AM CDT	Special Marine Warning	LOT		83 min
Apr 10, 5:20 AM CDT	Special Weather Statement	LOT	LaSalle	40 min
Apr 10, 6:55 AM CDT	Special Weather Statement	LOT	Iroquois	50 min
Apr 10, 12:26 PM CDT	Special Weather Statement	LOT	Grundy, Kendall, LaSalle, Will	49 min
Apr 10, 1:10 PM CDT	Severe Thunderstorm Warning	LOT	Cook	29 min
Apr 10, 1:12 PM CDT	Special Marine Warning	LOT		93 min
Apr 10, 2:08 PM CDT	Special Weather Statement	LOT	Cook, DuPage, Kane, Kendall	52 min
Apr 10, 2:55 PM CDT	Special Weather Statement	LOT	Boone, DeKalb, Lake, Lee, McHenry, Ogle and 1 more	50 min
Apr 10, 4:14 PM CDT	Severe Thunderstorm Warning	LOT	Livingston	61 min
Apr 10, 4:18 PM CDT	Severe Thunderstorm Warning	LOT	Lake, McHenry	42 min
Apr 10, 4:24 PM CDT	Special Marine Warning	LOT		2 hr
Apr 10, 5:54 PM CDT	Special Weather Statement	LOT	Lake	51 min
Apr 10, 8:01 AM CDT	Special Weather Statement	LOT	Benton	29 min
Apr 10, 6:01 PM CDT	Special Weather Statement	LOT	Newton	29 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2017 Every severe thunderstorm warning in 2017

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.