Alert archive / Illinois / Flash Flood Warnings in 1993

Flash Flood Warning 9, NWS Chicago, IL

July 18, 19934 counties in Illinois

NWS Chicago, IL issued this flash flood warning at Jul 18, 1993, 4:33 PM CDT for 4 counties in Illinois. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Jul 18, 1993, 4:33 PM CDT (21:33 UTC)
Expired
Jul 18, 1993, 7:30 PM CDT
In force
3 hr
Issued by
NWS Chicago, IL
Area
Whole counties

Counties Cook County, IL, Kane County, IL, Lake County, IL, McHenry County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 9.6 hours before the alert went out and 262 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 1993-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Green Bay/Straub, WI at 12:00Z on 1993-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 138 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
16 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
560 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
138 m²/s²
0-3 km storm-relative helicity
203 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 18, 12:04 PM CDTSevere Thunderstorm WarningLOTMcHenry41 min
Jul 18, 12:38 PM CDTSevere Thunderstorm WarningLOTKane52 min
Jul 18, 2:07 PM CDTSevere Thunderstorm WarningLOTCook, Lake68 min
Jul 18, 2:58 PM CDTSevere Thunderstorm WarningLOTCook62 min
Jul 18, 2:58 PM CDTSevere Thunderstorm WarningLOTDuPage27 min

Nearby

Flash Flood Warnings in Illinois, 1993Every flash flood warning in 1993

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.