Alert archive / Illinois / Flash Flood Warnings in 1997

Flash Flood Warning 21, NWS Chicago, IL

August 17, 1997Livingston County, Illinois

NWS Chicago, IL issued this flash flood warning at Aug 17, 1997, 2:45 AM CDT for Livingston County, Illinois. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 17, 1997, 2:45 AM CDT (07:45 UTC)
Expired
Aug 17, 1997, 8:45 AM CDT
In force
6 hr
Issued by
NWS Chicago, IL
Area
Whole counties

County Livingston County, IL

The radar

The Chicago radar (KLOT), 89 km from the middle of the area, began a volume at 07:49 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

Lincoln, IL (KILX), launched 00:00Z, 7.8 hours before the alert went out and 83 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, Lincoln, IL at 00:00Z on 1997-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5712 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 1997-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 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
5712 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
995 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
317 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KCHI 170748
FFWCHI
ILC105-171345-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHICAGO IL
245 AM CDT SUN AUG 17 1997

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL 845 AM CDT FOR PERSONS IN THE FOLLOWING LOCATIONS...

IN  CENTRAL ILLINOIS
   ...SOUTHERN LIVINGSTON

AT 230 AM CDT THIS MORNING...A CLUSTER OF THUNDERSTORMS WAS RETURNING
NORTHEASTWARD INTO LIVINGSTON COUNTY. THE PREVIOUS PASSAGE OF STORMS
DUMPED 1 TO 2 INCHES OF RAIN ACROSS SOUTHERN LIVINGSTON COUNTY. WHILE
LIGHT TO MODERATE RAINS KEPT THE GROUND SATURATED SINCE MIDNIGHT...THIS
NEW SURGE OF RAIN FROM APPROACHING STORMS WILL PUSH THE TOTAL AMOUNT OF
RAIN TO NEAR 4 INCHES IN THE LAST 3 HOURS.

THE HEAVIEST RAINFALL AND SUBSEQUENT FLOODING WILL OCCUR SOUTH OF 
ROUTE 116 AND INCLUDES FAIRBURY...STRAWN...AND CHATSWORTH.  SOME
FLOODING IS ALSO POSSIBLE UP TO ROUTE 116 NEAR THE TOWNS OF FLANAGAN AND
PONTIAC.

RAIN WILL CONTINUE THROUGH THE NIGHTTIME HOURS...POSSIBLY ADDING ANOTHER
2 INCHES TO THE TOTAL ALREADY.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARD TO RECOGNIZE THE DANGER
OF FLOODING.

$$
BRUMER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 7:02 PM CDTSevere Thunderstorm WarningLOTDeKalb28 min
Aug 16, 7:29 PM CDTFlash Flood WarningLOTCook3 hr
Aug 16, 8:07 PM CDTSevere Thunderstorm WarningLOTGrundy, Kendall, Will68 min
Aug 16, 8:07 PM CDTSevere Thunderstorm WarningLOTLaSalle68 min
Aug 16, 9:02 PM CDTSevere Thunderstorm WarningLOTKankakee28 min
Aug 17, 1:05 AM CDTFlash Flood WarningLOTFord6 hr

Nearby

Flash Flood Warnings in Illinois, 1997Every flash flood warning in 1997

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.