Alert archive / Illinois / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 151, NWS Chicago, IL

August 27, 2024LaSalle County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Aug 27, 2024, 8:23 PM CDT for LaSalle County, Illinois. It was in force for 37 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 27, 2024, 8:23 PM CDT (01:23 UTC)
Expired: Aug 27, 2024, 9:00 PM CDT
In force: 37 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County LaSalle County, IL

The radar

The Chicago radar (KLOT), 73 km from the middle of the area, began a volume at 01:27 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 27, 5:09 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

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 27, 6:55 PM CDT, 1 hour 28 minutes earlier.

Area forecast discussion, Aug 27, 6:55 PM CDT, 1 hour 28 minutes before

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Hazardous weather outlook, Aug 27, 3:44 PM CDT, 4 hours 39 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
344 PM CDT Tue Aug 27 2024

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-282045-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
344 PM CDT Tue Aug 27 2024 /444 PM EDT Tue Aug 27 2024/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

  Limited Thunderstorm Risk...with an associated:
     Level 2 of 5 Damaging Wind Risk...up to 60 mph.
     Level 2 of 5 Hail Risk...up to penny size.
     Level 1 of 4 Flooding Risk.
Significant Excessive Heat Risk.

DISCUSSION...

Hot and humid conditions will persist into this evening with
heat indices expected to drop below 100 degrees after sunset.

There remains a chance (30-40 percent) of scattered strong to
severe thunderstorms this evening into tonight. Damaging winds
would be the primary threat with any storms. Storms may also
produce locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...
  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Severe Thunderstorm Risk.
  Limited Excessive Heat Risk.
Thursday and Friday...
  Limited Thunderstorm Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed this evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east at 30 mph.

LMZ740>745-282045-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
344 PM CDT Tue Aug 27 2024

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Tonight.

Weather hazards expected...

  Limited Thunderstorm Risk...with an associated:
     Thunderstorm Waterspout Risk
     Level 2 of 5 Thunderstorm Wind Gust Risk...up to 50 knots.
     Level 2 of 5 Hail Risk...up to penny size.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday through Friday...
  Limited Thunderstorm Risk.
Sunday and Monday...
  Hazardous conditions for small craft are likely.

KJB

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In the hours before

Local storm report, Aug 27, 5:24 PM CDT, 2 hours 59 minutes before

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Local storm report, Aug 27, 5:34 PM CDT, 2 hours 49 minutes before

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Local storm report, Aug 27, 6:03 PM CDT, 2 hours 20 minutes before

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Local storm report, Aug 27, 6:09 PM CDT, 2 hours 14 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 27, 7:04 PM CDT	Special Marine Warning	LOT		71 min
Aug 27, 7:16 PM CDT	Special Weather Statement	LOT	Cook, DuPage	29 min
Aug 27, 7:31 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	29 min
Aug 27, 7:41 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook	34 min
Aug 27, 7:44 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, DuPage	31 min
Aug 27, 8:09 PM CDT	Areal Flood Advisory	LOT	Cook, DuPage	3 hr
Aug 27, 8:18 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Will	42 min
Aug 27, 8:55 PM CDT	Areal Flood Advisory	LOT	LaSalle	3 hr
Aug 27, 9:10 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle	50 min
Aug 27, 10:11 PM CDT	Special Weather Statement	LOT	Kankakee	34 min
Aug 27, 10:30 PM CDT	Special Weather Statement	LOT	Kankakee	30 min
Aug 27, 8:00 PM CDT	Special Weather Statement	LOT	Porter	30 min
Aug 27, 8:31 PM CDT	Severe Thunderstorm Warning	LOT	Lake	29 min
Aug 27, 9:21 PM CDT	Areal Flood Advisory	LOT	Porter	109 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2024 Every severe thunderstorm warning in 2024

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.