Alert archive / Illinois / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 9, NWS Chicago, IL

March 4, 2024Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Mar 4, 2024, 2:34 PM CST for Winnebago 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
Mar 4, 2024, 2:34 PM CST (20:34 UTC)
Expired
Mar 4, 2024, 3:15 PM CST
In force
41 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

County Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 86 km from the middle of the area, began a volume at 20:36 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

Davenport, (KDVN), launched 12:00Z, 8.6 hours before the alert went out and 136 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2024-03-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2024-03-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1669 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
126 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 Mar 4, 1:49 PM CST, 45 minutes earlier.

Area forecast discussion, Mar 4, 1:49 PM CST, 45 minutes before
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Hazardous weather outlook, Mar 4, 2:28 PM CST, 6 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
228 PM CST Mon Mar 4 2024

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-052030-
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-
228 PM CST Mon Mar 4 2024 /328 PM EST Mon Mar 4 2024/

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

.DAY ONE...Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Limited Hail Risk...up to 1 inch in diameter.
     Limited Damaging Wind Risk...up to 50 mph.

DISCUSSION...

Showers and thunderstorms will continue developing along and ahead
of a cold front this afternoon and evening, and then move across
the entire area overnight. The strongest storms may produce
locally damaging hail and gusty winds, as well as frequent cloud
to ground lightning and downpours.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

 Spotters may be needed this afternoon though this evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the northeast at 40 mph.

LMZ740>745-052030-
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-
228 PM CST Mon Mar 4 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...

  Hazardous conditions for small craft.
  Elevated Thunderstorm Risk Tonight...with an associated:
     Limited Hail Risk...up to Quarter size.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Tuesday, Wednesday, and Friday through Sunday...
  Hazardous conditions for small craft are likely.

Borchardt

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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 4, 3:05 AM CSTSmall Craft AdvisoryLOT66 hr
Mar 4, 6:39 AM CSTDense Fog AdvisoryLOTDeKalb, Kane, Kendall, LaSalle, Lee, Ogle2 hr
Mar 4, 3:05 PM CSTSevere Thunderstorm WarningLOTOgle40 min
Mar 4, 4:41 PM CSTSevere Thunderstorm WarningLOTLee, Ogle34 min
Mar 4, 5:04 PM CSTSevere Thunderstorm WarningLOTOgle41 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2024Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.