Alert archive / Illinois / Flash Flood Warnings in 1991

Flash Flood Warning 2, NWS Chicago, IL

May 30, 1991LaSalle County, Illinois

NWS Chicago, IL issued this flash flood warning at May 30, 1991, 10:03 PM CDT for LaSalle County, Illinois. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
May 30, 1991, 10:03 PM CDT (03:03 UTC)
Expired
May 31, 1991, 1:00 AM CDT
In force
3 hr
Issued by
NWS Chicago, IL
Area
Whole counties

County LaSalle County, IL

The nearest sounding before it

Dayton/James M C, OH (KDAY), launched 00:00Z, 3.1 hours before the alert went out and 427 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 00:00Z on 1991-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2324 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1991-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 square meters per square second.19395878Sfc1 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
2324 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
1089 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.5

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
May 30, 7:10 PM CDTSevere Thunderstorm WarningLOTLaSalle65 min
May 30, 8:20 PM CDTSevere Thunderstorm WarningLOTLaSalle40 min
May 30, 8:54 PM CDTSevere Thunderstorm WarningLOTLaSalle51 min
May 31, 3:32 PM CDTSevere Thunderstorm WarningLOTKane58 min
May 31, 4:23 PM CDTSevere Thunderstorm WarningLOTCook, Kane67 min
May 31, 5:24 PM CDTSevere Thunderstorm WarningLOTCook, Will66 min
May 31, 5:55 PM CDTSevere Thunderstorm WarningLOTKankakee65 min

Nearby

Flash Flood Warnings in Illinois, 1991Every flash flood warning 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.