Alert archive / Illinois / Flash Flood Warnings in 2002

Flash Flood Warning 26, NWS St. Louis, MO

July 18, 2002Clinton County, Saint Clair County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jul 18, 2002, 1:43 PM CDT for Clinton County, Saint Clair County, Illinois. It was in force for 3 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
Jul 18, 2002, 1:43 PM CDT (18:43 UTC)
Expired
Jul 18, 2002, 4:45 PM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Clinton County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 89 km from the middle of the area, began a volume at 18:46 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 12:00Z, 6.7 hours before the alert went out and 202 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 12:00Z on 2002-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1341 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, Lincoln, IL at 12:00Z on 2002-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
1341 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
-23 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 
WGUS53 KLSX 181843
FFWSTL
ILC027-163-182145-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
140 PM CDT THU JUL 18 2002

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS
  ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 445 PM CDT

* AT 138 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS PRODUCING VERY HEAVY RAIN IN A NARROW AREA FROM 
  NORTHERN ST. CLAIR COUNTY...WEST OF OFALLON ILLINOIS...INTO MUCH 
  OF CLINTON COUNTY.  A STORM SPOTTER HAS REPORTED NEARLY 3 INCHES
  OF RAIN IN THE OFALLON AREA...WITH ADDITIONAL STORMS ON THE WAY. 

* FLASH FLOODING CAN BE EXPECTED ACROSS THE AREA...AND WILL BE
  AFFECTING THE CITIES OF OFALLON...TRENTON...AND CARLYLE.   
  WHHILE THE FLOOD PRODUCING RAINS WILL NOT BE WIDESPREAD...THE
  STORMS ARE FOCUSING OVER NARROW AREAS...CREATING EXTREMELY HEAVY
  RAINFALLS.
 
MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES DO NOT ATTEMPT TO
CROSS BRIDGES...DIPS...OR LOW WATER CROSSINGS IF WATER COVERS THE
ROADWAY. DO NOT DRIVE AROUND BARRICADES IF YOUR VEHICLE STALLS...
ABANDON IT IMMEDIATELY AND SEEK HIGHER GROUND.

DURING HEAVY RAINS...KEEP CHILDREN AWAY FROM CREEKS AND STORM DRAINS.
GENTLY FLOWING WATER CAN TURN INTO A RAGING TORRENT IN A MATTER OF
MINUTES.

TRUETT/TES

Nearby

Flash Flood Warnings in Illinois, 2002Every flash flood warning in 2002

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.