Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 19, NWS St. Louis, MO

April 25, 20116 counties in Illinois

NWS St. Louis, MO issued this flash flood warning at Apr 25, 2011, 9:00 PM CDT for 6 counties in Illinois. It was in force for 6 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 25, 2011, 9:00 PM CDT (02:00 UTC)
Expired
Apr 26, 2011, 3:00 AM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Bond County, IL, Clinton County, IL, Fayette County, IL, Madison County, IL, Marion County, IL, Montgomery County, IL

The radar

The Lincoln radar (KILX), 128 km from the middle of the area, began a volume at 02:04 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.

What was reported inside it

TimeReportWhereRemark
Apr 26, 2:21 AM CDTFLASH FLOODVandalia, ILMANY ROADS ACROSS THE COUNTY AFFECTED BY HIGH WATER

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.0 hours before the alert went out and 131 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 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 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 2011-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 square meters per square second.1939587897Sfc1 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
48 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
580 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

013 
WGUS53 KLSX 260200
FFWLSX
ILC005-027-051-119-121-135-260800-
/O.NEW.KLSX.FF.W.0019.110426T0200Z-110426T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
900 PM CDT MON APR 25 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BOND COUNTY IN SOUTH CENTRAL ILLINOIS...
  EXTREME SOUTHEASTERN MADISON COUNTY IN SOUTHWEST ILLINOIS...
  FAYETTE COUNTY IN SOUTH CENTRAL ILLINOIS...
  NORTHERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
  NORTHWESTERN MARION COUNTY IN SOUTH CENTRAL ILLINOIS...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 300 AM CDT TUESDAY

* AT 858 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE  
  WARNED AREA. STANDING WATER WAS REPORTED ON SOME ROADS AND
  AN ADDITIONAL 1 TO 2 INCHES OF RAIN IS EXPECTED...WHICH WILL
  AGGRAVATE CURRENT CONDITIONS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BREESE...CARLYLE...GREENVILLE...HILLSBORO...NOKOMIS...VANDALIA...
  ALBERS...AVISTON...BEAVER CREEK...BECKEMEYER...BOULDER...
  BROWNSTOWN...COFFEEN...FARINA...JAMESTOWN...MULBERRY GROVE...
  PATOKA...POCAHONTAS...RAMSEY...RENO...SHOBONIER...SORENTO...ST.
  ELMO...ST. ROSE...TAMALCO...TAYLOR SPRINGS...VAN BURENSBURG...
  WITT...WOBURN AND WRIGHTS CORNER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3884 8870 3852 8967 3935 8953 3936 8914
      3922 8913 3922 8881 3892 8881 3892 8870

$$

GLASS
1 follow-up statement
934 
WGUS73 KLSX 260755
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
255 AM CDT TUE APR 26 2011

ILC005-027-051-119-121-135-260809-
/O.EXP.KLSX.FF.W.0019.000000T0000Z-110426T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY IL-CLINTON IL-MARION IL-MADISON IL-BOND IL-FAYETTE IL-
255 AM CDT TUE APR 26 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR FAYETTE...BOND...
EXTREME SOUTHEASTERN MADISON...NORTHWESTERN MARION...NORTHERN CLINTON
AND SOUTHEASTERN MONTGOMERY COUNTIES WILL BE ALLOWED TO EXPIRE AT 300
AM CDT...

THE HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS AND CREEKS IN 
THE WARNED AREA WILL CONTINUE TO CAUSE MINOR FLOODING...BUT LIFE 
THREATENING FLASH FLOODING IS NOT EXPECTED TO OCCUR.

LAT...LON 3884 8870 3852 8967 3935 8953 3936 8914
      3922 8913 3922 8881 3892 8881 3892 8870

$$

CVKING

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 7:23 PM CDTFlash Flood WarningLSXClinton, Marion, Monroe, Randolph, Saint Clair, Washington9 hr
Apr 25, 7:47 PM CDTSevere Thunderstorm WarningLSXWashington28 min
Apr 26, 4:50 AM CDTAreal Flood WarningLSXClinton, Marion, Monroe, Randolph, Saint Clair, Washington30 hr

Nearby

Flash Flood Warnings in Illinois, 2011Every flash flood warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.