Alert archive / Illinois / Flash Flood Warnings in 2009

Flash Flood Warning 41, NWS St. Louis, MO

June 10, 2009Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 10, 2009, 8:58 PM CDT for Monroe County, Saint Clair County, 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
Jun 10, 2009, 8:58 PM CDT (01:58 UTC)
Expired
Jun 11, 2009, 3:00 AM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Monroe County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 61 km from the middle of the area, began a volume at 01:58 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.

What was reported inside it

TimeReportWhereRemark
Jun 10, 10:16 PM CDTFLASH FLOODMascoutah, IL6 INCHES OF WATER FLOWING ACROSS HIGHWAY 177 AND HIGHWAY 4 IN MASCOUTAH.

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 241 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 2009-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 729 joules per kilogram.LCLLFCEL10008507005003002001001 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 2009-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.19395878Sfc1 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
729 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1199 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KLSX 110158
FFWLSX
ILC133-163-110800-
/O.NEW.KLSX.FF.W.0041.090611T0158Z-090611T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
858 PM CDT WED JUN 10 2009

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MONROE COUNTY IN SOUTHWEST ILLINOIS
  ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 300 AM CDT THURSDAY

* AT 856 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. 1 TO LOCALLY 4 INCHES OF RAINFALL IS EXPECTED WITH    
  THIS THUNDERSTORM COMPLEX WHICH WILL LIKELY LEAD TO FLASH          
  FLOODING. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BELLEVILLE...CAHOKIA...CASEYVILLE...CENTREVILLE...COLUMBIA...
  DUPO...EAST ST. LOUIS...FAIRVIEW HEIGHTS...FREEBURG...LEBANON...
  MASCOUTAH...MILLSTADT...OFALLON...SCOTT AFB...SHILOH...SWANSEA...
  WASHINGTON PARK...WATERLOO...BROOKLYN...EAST CARONDELET...FAIRMONT
  CITY...FOUNTAIN...MARISSA...NEW ATHENS...NEW DESIGN...SMITHTON AND
  VALMEYER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

LAT...LON 3822 9004 3814 9004 3809 9021 3815 9028
      3821 9035 3829 9038 3837 9036 3844 9029
      3855 9025 3861 9018 3866 9018 3866 8971
      3822 8971

$$

CVKING
1 follow-up statement
000 
WGUS73 KLSX 110444
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1144 PM CDT WED JUN 10 2009

ILC133-163-110800-
/O.CON.KLSX.FF.W.0041.000000T0000Z-090611T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONROE IL-ST. CLAIR IL-
1144 PM CDT WED JUN 10 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR ST. CLAIR AND MONROE
COUNTIES UNTIL 300 AM CDT...

ALTHOUGH THE THUNDERSTORMS AND RAINFALL HAVE ENDED...WIDESPREAD 
RAINFALL AMUNTS OF 1 TO 2 INCHES WITH LOCALIZED AMOUNTS OF UP TO 4 
INCHES WITH THE MAJORITY OF IT FALLING WITHIN AN HOUR WILL CONTINUE 
TO RUN OFF TONIGHT KEEPING CREEKS AND STREAMS RUNNING HIGH.

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...BELLEVILLE...CAHOKIA...CASEYVILLE...CENTREVILLE...
COLUMBIA...DUPO...EAST ST. LOUIS...FAIRVIEW HEIGHTS...FREEBURG...
LEBANON...MASCOUTAH...MILLSTADT...OFALLON...SCOTT AFB...SHILOH...
SWANSEA...WASHINGTON PARK...WATERLOO...BROOKLYN...EAST CARONDELET...
FAIRMONT CITY...FOUNTAIN...MARISSA...NEW ATHENS...NEW DESIGN...
SMITHTON AND VALMEYER.

AT 1015 PM...AN AMATEUR RADIO OPERATOR REPORTED 6 INCHES OF WATER 
FLOWING OVER THE INTERSECTION OF ILLINOIS HIGHWAYS 177 AND 4 IN 
MASCOUTAH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

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 3822 9004 3814 9004 3809 9021 3815 9028
      3821 9035 3829 9038 3837 9036 3844 9029
      3855 9025 3861 9018 3866 9018 3866 8971
      3822 8971

$$

MILLER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 10, 8:27 PM CDTSevere Thunderstorm WarningLSXSaint Clair37 min
Jun 10, 8:31 PM CDTSevere Thunderstorm WarningLSXMonroe, Saint Clair44 min
Jun 10, 9:53 PM CDTSevere Thunderstorm WarningLSXSaint Clair24 min
Jun 10, 10:02 PM CDTTornado WarningLSXFayette28 min
Jun 11, 3:08 AM CDTAreal Flood WarningLSXSaint Clair6 hr
Jun 11, 11:05 AM CDTRiver Flood WarningLSXCalhoun, Jersey71 hr
Jun 11, 2:20 PM CDTAreal Flood AdvisoryLSXMontgomery6 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.