Alert archive / Illinois / Flash Flood Warnings in 1994

Flash Flood Warning 16, NWS St. Louis, MO

April 12, 1994Monroe County, Illinois; Jefferson County, Missouri

NWS St. Louis, MO issued this flash flood warning at Apr 12, 1994, 2:56 AM CDT for Monroe County, Illinois; Jefferson County, Missouri. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued: Apr 12, 1994, 2:56 AM CDT (07:56 UTC)
Expired: Apr 12, 1994, 8:00 AM CDT
In force: 5 hr
Issued by: NWS St. Louis, MO
Area: Whole counties

Counties Monroe County, IL, Jefferson County, MO

The radar

The St Louis radar (KLSX), 55 km from the middle of the area, began a volume at 07:58 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

Paducah/Barkley, KY (KPAH), launched 00:00Z, 7.9 hours before the alert went out and 198 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 427 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 1170 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTL 120759
FFWSTL
ILC133-163-MOC099-121300-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
256 AM CDT TUE APR 12 1994
 
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  800 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHWEST ILLINOIS
 
   ...MONROE COUNTY...ST CLAIR COUNTY
 
 
IN EAST CENTRAL MISSOURI
 
   ...JEFFERSON COUNTY
 
BETWEN 130 AND 245 AM...A THUNDERSTORM PRODUCED HEAVY RAIN JUST TO THE
SOUTH AND SOUTHEAST OF ST. LOUIS. THIS ADDITIONAL HEAVY RAIN HAS RENEWED
DANGEROUS FLOODING CONDITIONS OVER JEFFERSON COUNTY MISSOURI AND MONROE
AND ST. CLAIR COUNTIES IN ILLINOIS.
 
AT 250 AM...A FLOOD EMERGENCY WAS REPORTED IN THE CITY OF
DESOTO IN JEFFERSON COUNTY.  JOACHIM CREEK WAS AGAIN FLOODING AND SOME
RESIDENCES WERE BEING THREATENED BY THE WATER.
 
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
 
GKS/TRUETT
 
&

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 11, 8:06 PM CDT	Flash Flood Warning	LSX	Pike	6 hr
Apr 11, 8:06 PM CDT	Flash Flood Warning	LSX	Calhoun	6 hr
Apr 11, 9:26 PM CDT	Flash Flood Warning	LSX	Scott	5 hr
Apr 12, 1:59 AM CDT	Flash Flood Warning	LSX	Calhoun, Pike	6 hr
Apr 12, 1:59 AM CDT	Flash Flood Warning	LSX	Greene, Scott	6 hr
Apr 12, 2:56 AM CDT	Flash Flood Warning	LSX	Saint Clair	5 hr

Nearby

Flash Flood Warnings in Illinois, 1994 Flash Flood Warnings in Missouri, 1994 Every flash flood warning in 1994

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.