Alert archive / Illinois / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 20, NWS Chicago, IL

May 9, 2018Ford County, Iroquois County, Livingston County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 9, 2018, 5:52 PM CDT for Ford County, Iroquois County, Livingston County, Illinois. It was in force for 38 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 9, 2018, 5:52 PM CDT (22:52 UTC)
Expired: May 9, 2018, 6:30 PM CDT
In force: 38 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Ford County, IL, Iroquois County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 96 km from the middle of the area, began a volume at 22:52 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, 10.9 hours before the alert went out and 74 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: 1485 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 347 m²/s²
0-3 km storm-relative helicity: 285 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 May 9, 3:30 PM CDT, 2 hours 22 minutes earlier.

Area forecast discussion, May 9, 3:30 PM CDT, 2 hours 22 minutes before

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Hazardous weather outlook, May 9, 3:39 PM CDT, 2 hours 13 minutes before

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In the hours before

Special weather statement, May 9, 5:25 PM CDT, 27 minutes before

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Special weather statement, May 9, 5:34 PM CDT, 18 minutes before

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Local storm report, May 9, 5:43 PM CDT, 9 minutes before

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Local storm report, May 9, 5:47 PM CDT, 5 minutes before

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Special weather statement, May 9, 5:48 PM CDT, 4 minutes before

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Special weather statement, May 9, 5:49 PM CDT, 3 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 9, 3:40 AM CDT	Special Weather Statement	LOT	Ogle	20 min
May 9, 4:32 PM CDT	Special Weather Statement	LOT	Lake	28 min
May 9, 4:35 PM CDT	Special Weather Statement	LOT	Lake	40 min
May 9, 4:52 PM CDT	Special Marine Warning	LOT		53 min
May 9, 4:57 PM CDT	Special Weather Statement	LOT	DuPage	33 min
May 9, 5:02 PM CDT	Severe Thunderstorm Warning	LOT	DuPage	16 min
May 9, 5:15 PM CDT	Special Weather Statement	LOT	Cook	45 min
May 9, 5:25 PM CDT	Special Weather Statement	LOT	Ford	50 min
May 9, 5:26 PM CDT	Special Marine Warning	LOT		64 min
May 9, 5:34 PM CDT	Special Weather Statement	LOT	Cook	11 min
May 9, 5:48 PM CDT	Special Weather Statement	LOT	Cook	27 min
May 9, 5:49 PM CDT	Special Weather Statement	LOT	Kankakee	26 min
May 9, 6:02 PM CDT	Severe Thunderstorm Warning	LOT	Kankakee	28 min
May 9, 6:18 PM CDT	Severe Thunderstorm Warning	LOT	Iroquois, Kankakee	42 min
May 9, 6:33 PM CDT	Special Weather Statement	LOT	Ford	42 min
May 9, 6:54 PM CDT	Special Weather Statement	LOT	Iroquois	51 min
May 9, 6:58 PM CDT	Special Weather Statement	LOT	Iroquois	62 min
May 9, 8:25 AM CDT	Special Weather Statement	LOT	Jasper, Newton	35 min
May 9, 6:34 PM CDT	Severe Thunderstorm Warning	LOT	Porter	26 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2018 Every severe thunderstorm warning in 2018

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.