Alert archive / Illinois / Flash Flood Warnings in 2012

Flash Flood Warning 21, NWS St. Louis, MO

May 20, 2012Marion County, Illinois

NWS St. Louis, MO issued this flash flood warning at May 20, 2012, 5:06 PM CDT for Marion County, Illinois. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 20, 2012, 5:06 PM CDT (22:06 UTC)
Expired
May 20, 2012, 9:00 PM CDT
In force
4 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Marion County, IL

The radar

The Evansville,IN radar (KVWX), 115 km from the middle of the area, began a volume at 22:06 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

Lincoln, IL (KILX), launched 12:00Z, 10.1 hours before the alert went out and 174 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 2012-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 616 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 12:00Z on 2012-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -67 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
616 J/kg
Mixed-layer CIN
-119 J/kg
Mixed-layer LCL
1773 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-67 m²/s²
0-3 km storm-relative helicity
-55 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.

759 
WGUS53 KLSX 202206
FFWLSX
ILC121-210200-
/O.NEW.KLSX.FF.W.0021.120520T2206Z-120521T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
506 PM CDT SUN MAY 20 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MARION COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 900 PM CDT

* AT 506 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  SLOW MOVINGTHUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. RADAR ESTIMATES BETWEEN TWO AND THREE INCHES OF 
  RAINFALL HAVE FALLEN OVER PARTS OF WESTERN MARION COUNTY OVER THE 
  PAST HOUR OR TWO...IN THE REGION BETWEEN FAIRMAN AND ODIN.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CENTRALIA...SALEM...CENTRAL CITY...FAIRMAN...HELM...KINMUNDY...
  ODIN...OMEGA...PATOKA...SANDOVAL AND STEPHEN FORBES STATE PARK.

ADDITIONAL SLOW MOVING AND HEAVY RAIN PRODUCING THUNDERSTORMS ARE 
EXPECTED IN OTHER SECTIONS OF THE COUNTY AS WELL OVER THE NEXT FEW 
HOURS. 

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.

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

&&

LAT...LON 3847 8914 3882 8914 3883 8870 3848 8870

$$

TES
2 follow-up statements
034 
WGUS73 KLSX 210029
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
729 PM CDT SUN MAY 20 2012

ILC121-210200-
/O.CON.KLSX.FF.W.0021.000000T0000Z-120521T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARION IL-
729 PM CDT SUN MAY 20 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR MARION COUNTY UNTIL 900
PM CDT...

AT 720 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA... 
WHERE ESTIMATES OF UP TO THREE INCHES OF RAINFALL EXIST FOR AREAS 
SOUTH AND WEST OF SALEM.  SPECIFICALLY...BETWEEN THE ODIN AND 
FAIRMAN AREAS AND THE AREA SOUTH OF SELMAVILLE.

REPORTS SO FAR OUT OF MARION COUNTY INDICATE ONLY MINOR FLOOWING FOR 
THE AREAS TO THE SOUTH AND WEST OF SALEM.  HOWEVER...ADDITIONAL 
HEAVY RAIN PRODUCING THUNDERSTORMS ARE LIKELY HEADING INTO THE MID 
AND LATE PARTS OF THE EVENING.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CENTRALIA...SALEM...CENTRAL CITY...FAIRMAN...HELM...KINMUNDY... 
ODIN...OMEGA...PATOKA...SANDOVAL AND STEPHEN FORBES STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLASH 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.

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 3847 8914 3882 8914 3883 8870 3848 8870

$$

TES
032 
WGUS73 KLSX 210159
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
859 PM CDT SUN MAY 20 2012

ILC121-210212-
/O.EXP.KLSX.FF.W.0021.000000T0000Z-120521T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARION IL-
859 PM CDT SUN MAY 20 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR MARION COUNTY WILL
BE ALLOWED TO EXPIRE AT 900 PM 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.

THERE WILL BE SCATTERED THUNDERSTORMS THAT WILL STILL PASS THROUGH 
THE AREA THROUGH MIDNIGHT...BUT HEAVY RAINFALL WILL BE A MINIMAL 
THREAT. 

LAT...LON 3847 8914 3882 8914 3883 8870 3848 8870

$$

TES

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 4:18 PM CDTSevere Thunderstorm WarningLSXGreene, Jersey, Macoupin27 min
May 20, 5:11 PM CDTSevere Thunderstorm WarningLSXCalhoun, Pike37 min

Nearby

Flash Flood Warnings in Illinois, 2012Every flash flood warning in 2012

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.