Alert archive / Illinois / Flash Flood Warnings in 2009

Flash Flood Warning 21, NWS St. Louis, MO

May 25, 2009Madison County, Illinois

NWS St. Louis, MO issued this flash flood warning at May 25, 2009, 11:55 AM CDT for Madison County, Illinois. It was in force for 5 hr. 6 reports 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
May 25, 2009, 11:55 AM CDT (16:55 UTC)
Expired
May 25, 2009, 5:12 PM CDT
In force
5 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Madison County, IL

The radar

The St Louis radar (KLSX), 73 km from the middle of the area, began a volume at 16:57 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
May 25, 12:11 PM CDTHEAVY RAIN 2Glen Carbon, ILTOTAL SO FAR...NO FLOODING OBSERVED AT TIME OF CALL
May 25, 2:12 PM CDTFLOODEdwardsville, ILREPORTED DRAINAGE DITCHES OVERFLOWING...STANDING WATER IN FIELDS...AND AN AVERAGE OF 3 INCHES OF WATER ON ROADWAYS
May 25, 2:27 PM CDTHEAVY RAIN 4Edwardsville, ILTOTAL SINCE MIDNIGHT...CREEKS OBSERVED TO BE OVERFLOWING...MINOR ROAD FLOODING
May 25, 2:29 PM CDTFLOODEdwardsville, ILMADISON COUNTY S.O. RELAYED SEVERAL REPORTS AROUND EDWARDSVILLE AND POINTS NORTH OF WATER FLOWING OVER COUNTY AND SECONDARY ROADS...NO ROADS CLOSED IN THE COUNTY AT THIS TIME DUE TO FLOODING
May 25, 2:37 PM CDTFLOODEdwardsville, ILREPORTED 6 TO 8 INCHES OF WATER FLOWING ACROSS ROADS...WATER STILL RISING
May 25, 3:11 PM CDTFLOODEdwardsville, ILSOME ROADS NEAR DOWNTOWN EDWARDSVILLE ARE IMPASSABLE... 12+ INCHES OF WATER IN LOW SPOTS

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 12:00Z, 4.9 hours before the alert went out and 179 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 2009-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2009-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1131 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
89 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 251655
FFWLSX
ILC119-252300-
/O.NEW.KLSX.FF.W.0021.090525T1655Z-090525T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1155 AM CDT MON MAY 25 2009

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL MADISON COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 600 PM CDT MONDAY

* AT 1149 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RADAR ESTIMATES IN EXCESS OF 3 INCHES WERE OBSERVED   
  IN A SMALL AREA JUST EAST OF EDWARDSVILLE.  THE CAHOKIA CREEK      
  BASIN HAS BEEN HIT ESPECIALLY HARD.  PEOPLE SHOULD EXPECT FLASH    
  FLOODING ALONG CAHOKIA CREEK AND ITS TRIBUTARIES THIS AFTERNOON.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BETHALTO...EDWARDSVILLE...GLEN CARBON...MARYVILLE...PONTOON
  BEACH...TROY...WOOD RIVER...ALHAMBRA...CARPENTER...DORSEY...       
  HARTFORD...LIVINGSTON...MARINE...PRAIRIETOWN...ROXANA...AND WORDEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT OR IN A VEHICLE.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN ST
LOUIS.

&&

LAT...LON 3899 8974 3872 8971 3871 9010 3900 9010

$$

CARNEY
2 follow-up statements
000 
WGUS73 KLSX 252023
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
323 PM CDT MON MAY 25 2009

ILC119-252300-
/O.CON.KLSX.FF.W.0021.000000T0000Z-090525T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MADISON IL-
323 PM CDT MON MAY 25 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL MADISON COUNTY
UNTIL 600 PM CDT...

AT 307 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY 
RAINFALL ACROSS THE WARNED AREA. DOPPLER RADAR ESTIMATED 2 TO 5 INCHES 
HAS FALLEN ACROSS THE WARNED ARE SINCE LATE THIS MORNING. THESE ESTIMATES 
HAVE BEEN VERIFIED BY SPOTTER REPORTS OF 2 TO 4 INCHES.

LOCAL LAW ENFORCEMENT REPORTS MANY COUNTY AND SECONDARY ROADS IN AND 
AROUND THE EDWARDSVILLE ARE AND POINTS NORTHWARD HAVE WATER FLOWING OVER 
THE ROADWAYS.  OTHER REPORTS INDICATE URBAN FLOODING IN PARTS OF 
EDWARDSVILLE WITH IN EXCESS OF A FOOT OF STANDING WATER NEAR THE DOWNTOWN 
AREA.

SLOW MOVING THUNDERSTORMS ARE PRODUCING VERY HEAVY RAINFALL IN THE
WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH
FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING
INCLUDE...BETHALTO...EDWARDSVILLE...GLEN CARBON...MARYVILLE...PONTOON
BEACH...TROY...WOOD RIVER...ALHAMBRA...CARPENTER...DORSEY...
HARTFORD...LIVINGSTON...MARINE...PRAIRIETOWN...ROXANA AND WORDEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE CAHOKIA CREEK BASIN CONTINUES TO BE AFFECTED BY THE HEAVY RAINFALL.
A GAGE ON CAHOKIA CREEK NEAR EDWARDSVILLE INDICATES THE WATER LEVEL HAS 
RISEN 15 FEET SINCE THIS MORNING AND IS STILL RISING.  ANYBODY ALONG 
CAHOKIA CREEK OR ITS TRIBUTARIES SHOULD PAY SPECIAL ATTENTION THIS 
SITUATION FOR THE REST OF THE DAY.  

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.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

REPORT FLOODING TO THE NEAREST LAW ENFORCEMENT AGENCY SO THAT THEY
MAY TAKE APPROPRIATE ACTION TO CLOSE FLOODED ROADWAYS. THEY WILL
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN ST LOUIS.

&&

LAT...LON 3899 8974 3872 8971 3871 9010 3900 9010

$$

MILLER
000 
WGUS73 KLSX 252212
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
512 PM CDT MON MAY 25 2009

ILC119-252225-
/O.CAN.KLSX.FF.W.0021.000000T0000Z-090525T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MADISON IL-
512 PM CDT MON MAY 25 2009

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL MADISON
COUNTY IS CANCELLED...

THE HEAVIEST RAIN PRODUCING THUNDERSTORMS HAVE EXITED THE WARNED 
AREA REDUCING THE RISK FOR FLASH FLOODING...HOWEVER RUNOFF FROM THE
EARLIER RAINFALL WILL CONTINUE THROUGH THE EVENING.  IF FLOODING IS 
OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3899 8974 3872 8971 3871 9010 3900 9010

$$

MILLER

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 11:00 AM CDTAreal Flood AdvisoryLSXMadison6 hr
May 25, 1:38 PM CDTTornado WarningLSXMacoupin37 min
May 25, 2:16 PM CDTTornado WarningLSXMadison29 min
May 25, 3:06 PM CDTFlash Flood WarningLSXMacoupin6 hr
May 25, 3:34 PM CDTAreal Flood AdvisoryLSXBond, Fayette, Montgomery6 hr
May 25, 5:00 PM CDTAreal Flood WarningLSXMadison6 hr
May 25, 5:09 PM CDTAreal Flood WarningLSXMadison6 hr

Nearby

Flash Flood Warnings in Illinois, 2009Every flash flood warning in 2009

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.