Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 8, NWS St. Louis, MO

April 22, 2011Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this flash flood warning at Apr 22, 2011, 9:30 PM CDT for Monroe County, Saint Clair County, Illinois. It was in force for 5 hr. 4 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
Apr 22, 2011, 9:30 PM CDT (02:30 UTC)
Expired
Apr 23, 2011, 2:00 AM CDT
In force
5 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), 64 km from the middle of the area, began a volume at 02:33 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 22, 9:30 PM CDTFLASH FLOOD2 Sse Fountain, ILEARLIER A CREEK WAS OUT OF ITS BANKS ON BLUFF ROAD NEAR INTERSECTION WITH TROUT ROAD.
Apr 22, 9:47 PM CDTFLASH FLOOD5 S Mascoutah, IL4-5 INCHES OF WATER ON HIGHWAY 4 SOUTH OF MASCOUTAH
Apr 22, 9:48 PM CDTFLASH FLOODFreeburg, ILPONDING OF WATER AT LEAST 10 INCHES DEEP...WATER UP TO CAR DOORS AT DEERFIELD TRAILER PARK AT HIGHWAYS 13 AND 15
Apr 22, 9:48 PM CDTHEAVY RAIN 1.86Freeburg, IL1.86 INCHES OF RAIN IN ONE HOUR

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, 2.5 hours before the alert went out and 245 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 2011-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 342 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 00:00Z on 2011-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 351 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
342 J/kg
Mixed-layer CIN
-152 J/kg
Mixed-layer LCL
492 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
351 m²/s²
0-3 km storm-relative helicity
346 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

335 
WGUS53 KLSX 230230
FFWLSX
ILC133-163-230700-
/O.NEW.KLSX.FF.W.0008.110423T0230Z-110423T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
930 PM CDT FRI APR 22 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 200 AM CDT

* AT 929 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
  RAINFALLS IN EXCESS OF ONE INCH HAVE BEEN REPORTED THIS EVENING...
  IN LOCATIONS THAT RECEIVED 2 TO 4 INCHES OF RAIN EARLY THIS
  MORNING.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  COLUMBIA...DUPO...FREEBURG...MASCOUTAH...MILLSTADT...WATERLOO...
  FOUNTAIN...MARISSA...NEW ATHENS...NEW DESIGN...SMITHTON AND
  VALMEYER.

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.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

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

&&

LAT...LON 3823 8972 3822 9004 3812 9024 3817 9030
      3819 9034 3828 9037 3834 9037 3837 9036
      3845 9029 3852 9026 3853 8971

$$

TRUETT
1 follow-up statement
815 
WGUS73 KLSX 230657
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
157 AM CDT SAT APR 23 2011

ILC133-163-230712-
/O.EXP.KLSX.FF.W.0008.000000T0000Z-110423T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONROE IL-ST. CLAIR IL-
157 AM CDT SAT APR 23 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN ST. CLAIR
AND MONROE COUNTIES WILL BE ALLOWED TO EXPIRE AT 200 AM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3823 8972 3822 9004 3812 9024 3817 9030
      3819 9034 3828 9037 3834 9037 3837 9036
      3845 9029 3852 9026 3853 8971

$$

BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 22, 7:59 PM CDTTornado WarningLSXMadison, Saint Clair46 min
Apr 22, 8:21 PM CDTTornado WarningLSXMonroe, Saint Clair39 min
Apr 22, 8:33 PM CDTTornado WarningLSXMadison, Saint Clair42 min
Apr 22, 8:48 PM CDTTornado WarningLSXMonroe, Saint Clair57 min
Apr 22, 8:55 PM CDTTornado WarningLSXBond, Clinton, Fayette, Madison, Saint Clair50 min
Apr 22, 9:01 PM CDTSevere Thunderstorm WarningLSXFayette, Marion20 min
Apr 22, 9:24 PM CDTTornado WarningLSXClinton, Washington36 min
Apr 22, 9:41 PM CDTTornado WarningLSXBond, Fayette, Marion22 min
Apr 22, 9:51 PM CDTFlash Flood WarningLSXClinton, Washington5 hr
Apr 22, 9:59 PM CDTSevere Thunderstorm WarningLSXClinton, Marion, Washington11 min
Apr 22, 10:31 PM CDTTornado WarningLSXMonroe, Randolph, Saint Clair44 min
Apr 22, 10:55 PM CDTFlash Flood WarningLSXMonroe, Randolph6 hr
Apr 22, 11:38 PM CDTRiver Flood WarningLSXBrown25 days
Apr 22, 11:38 PM CDTRiver Flood WarningLSXMorgan, Pike25 days
Apr 22, 11:38 PM CDTRiver Flood WarningLSXPike, Scott31 days
Apr 22, 11:53 PM CDTRiver Flood WarningLSXSaint Clair14 days
Apr 23, 4:23 AM CDTFlash Flood WarningLSXMonroe, Randolph8 hr
Apr 23, 12:29 PM CDTFlash Flood WarningLSXMonroe, Randolph6 hr
Apr 23, 6:22 PM CDTFlash Flood WarningLSXMonroe, Randolph6 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.