Alert archive / Illinois / Tornado Warnings in 1991

Tornado Warning 2, NWS Chicago, IL

March 27, 1991Cook County, Lake County, Illinois

NWS Chicago, IL issued this tornado warning at Mar 27, 1991, 7:45 AM CST for Cook County, Lake County, Illinois. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
Mar 27, 1991, 7:45 AM CST (13:45 UTC)
Expired
Mar 27, 1991, 8:15 AM CST
In force
30 min
Issued by
NWS Chicago, IL
Area
Whole counties

Counties Cook County, IL, Lake County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 1.8 hours before the alert went out and 264 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, Green Bay/Straub, WI at 12:00Z on 1991-03-27Temperature 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, Green Bay/Straub, WI at 12:00Z on 1991-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.1939587897Sfc1 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
1516 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 26, 11:48 PM CSTSevere Thunderstorm WarningLOTGrundy, LaSalle42 min
Mar 26, 11:48 PM CSTSevere Thunderstorm WarningLOTLivingston57 min
Mar 26, 11:48 PM CSTSevere Thunderstorm WarningLOTWill57 min
Mar 27, 1:00 AM CSTSevere Thunderstorm WarningLOTGrundy, LaSalle, Livingston60 min
Mar 27, 2:17 AM CSTSevere Thunderstorm WarningLOTCook, Will43 min
Mar 27, 7:41 AM CSTSevere Thunderstorm WarningLOTCook, Lake34 min
Mar 27, 2:13 PM CSTSevere Thunderstorm WarningLOTMcHenry62 min
Mar 27, 2:32 PM CSTTornado WarningLOTLaSalle28 min
Mar 27, 3:00 PM CSTTornado WarningLOTGrundy, Kendall, LaSalle45 min
Mar 27, 3:04 PM CSTSevere Thunderstorm WarningLOTLake26 min
Mar 27, 3:23 PM CSTSevere Thunderstorm WarningLOTCook, Lake52 min
Mar 27, 3:33 PM CSTTornado WarningLOTDuPage, Will42 min
Mar 27, 3:53 PM CSTTornado WarningLOTGrundy, Kendall, LaSalle52 min
Mar 27, 4:07 PM CSTTornado WarningLOTCook28 min
Mar 27, 4:09 PM CSTTornado WarningLOTKankakee, Will36 min
Mar 27, 4:44 PM CSTTornado WarningLOTLake, Porter31 min

Nearby

Tornado Warnings in Illinois, 1991Every tornado warning in 1991Tornadoes in 1991

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.