Alert archive / Indiana / Tornado Warnings in 1991

Tornado Warning 20, NWS Chicago, IL

July 7, 1991Lake County, Indiana

NWS Chicago, IL issued this tornado warning at Jul 7, 1991, 5:55 PM CDT for Lake County, Indiana. It was in force for 35 min.

The area

The counties it named.

The facts

Issued
Jul 7, 1991, 5:55 PM CDT (22:55 UTC)
Expired
Jul 7, 1991, 6:30 PM CDT
In force
35 min
Issued by
NWS Chicago, IL
Area
Whole counties

County Lake County, IN

The nearest sounding before it

Dayton/James M C, OH (KDAY), launched 12:00Z, 10.9 hours before the alert went out and 320 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, Dayton/James M C, OH at 12:00Z on 1991-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1475 joules per kilogram.LCLLFCEL10008507005003002001001 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, Dayton/James M C, OH at 12:00Z on 1991-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 182 square meters per square second.193958Sfc1 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
1475 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
1222 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
182 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

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
Jul 7, 3:56 PM CDTSevere Thunderstorm WarningLOTMcHenry49 min
Jul 7, 4:49 PM CDTSevere Thunderstorm WarningLOTGrundy, Will41 min
Jul 7, 5:06 PM CDTTornado WarningLOTWill54 min
Jul 7, 5:11 PM CDTSevere Thunderstorm WarningLOTKendall34 min
Jul 7, 5:27 PM CDTSevere Thunderstorm WarningLOTGrundy33 min
Jul 7, 5:41 PM CDTSevere Thunderstorm WarningLOTKankakee49 min
Jul 7, 6:59 PM CDTSevere Thunderstorm WarningLOTLivingston31 min
Jul 7, 5:50 PM CDTSevere Thunderstorm WarningLOTPorter40 min

Nearby

Tornado Warnings in Indiana, 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.