Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 54, NWS St. Louis, MO

June 18, 2011Fayette County, Montgomery County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 18, 2011, 2:51 AM CDT for Fayette County, Montgomery County, Illinois. It was in force for 6 hr. 3 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
Jun 18, 2011, 2:51 AM CDT (07:51 UTC)
Expired
Jun 18, 2011, 9:00 AM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Fayette County, IL, Montgomery County, IL

The radar

The Lincoln radar (KILX), 122 km from the middle of the area, began a volume at 07:54 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 18, 4:00 AM CDTFLASH FLOOD1 N Irving, ILROUTE 16 FLOODED.
Jun 18, 4:00 AM CDTFLASH FLOODHillsboro, ILVIADUCT FLOODED IN TOWN.
Jun 18, 8:55 AM CDTFLASH FLOODHillsboro, ILNUMEROUS ROADS FLOODED IN THE NORTHERN AND EASTERN PORTIONS OF THE COUNTY.

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, 7.9 hours before the alert went out and 133 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 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 601 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 2011-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
601 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
644 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

271 
WGUS53 KLSX 180751
FFWLSX
ILC051-135-181400-
/O.NEW.KLSX.FF.W.0054.110618T0751Z-110618T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
251 AM CDT SAT JUN 18 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN FAYETTE COUNTY IN SOUTH CENTRAL ILLINOIS...
  SOUTHERN MONTGOMERY COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 900 AM CDT

* AT 250 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. ONE TO TWO INCHES OF RAIN HAS ALREADY FALLEN ACROSS 
  PORTIONS OF THE WARNED AREA WITH ANOTHER TWO INCHES EXPECTED OVER 
  THE NEXT COUPLE OF HOURS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  HILLSBORO...LITCHFIELD...VANDALIA...BROWNSTOWN...COFFEEN...
  RAMSEY...ST. ELMO...TAYLOR SPRINGS...VAN BURENSBURG AND WRIGHTS   
  CORNER.

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.

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 3896 8926 3903 8925 3903 8962 3924 8970
      3922 8880 3897 8880

$$

TILLY
1 follow-up statement
394 
WGUS73 KLSX 181358
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
858 AM CDT SAT JUN 18 2011

ILC051-135-181412-
/O.EXP.KLSX.FF.W.0054.000000T0000Z-110618T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY IL-FAYETTE IL-
858 AM CDT SAT JUN 18 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHERN FAYETTE
AND SOUTHERN MONTGOMERY COUNTIES WILL BE ALLOWED TO EXPIRE AT 900 AM
CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. 
HOWEVER...FLASH FLOODING IS ONGOING FURTHER TO THE NORTH WHERE 
ANOTHER FLASH FLOOD WARNING IS IN EFFECT UNTIL 1PM. 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 3896 8926 3903 8925 3903 8962 3924 8970
      3922 8880 3897 8880

$$

BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 12:30 AM CDTSevere Thunderstorm WarningLSXMacoupin, Montgomery45 min
Jun 18, 1:14 AM CDTFlash Flood WarningLSXMacoupin, Montgomery12 hr
Jun 18, 1:16 AM CDTSevere Thunderstorm WarningLSXMacoupin, Montgomery29 min
Jun 18, 4:31 AM CDTFlash Flood WarningLSXBond, Fayette6 hr
Jun 18, 5:01 AM CDTFlash Flood WarningLSXClinton, Marion6 hr
Jun 18, 5:10 AM CDTSevere Thunderstorm WarningLSXAdams, Brown, Calhoun, Greene, Pike65 min
Jun 18, 5:18 AM CDTSevere Thunderstorm WarningLSXCalhoun, Greene, Jersey, Madison, Monroe, Saint Clair57 min
Jun 18, 5:30 AM CDTTornado WarningLSXCalhoun, Greene, Jersey, Madison, Pike19 min
Jun 18, 6:09 AM CDTSevere Thunderstorm WarningLSXJersey, Macoupin, Madison, Montgomery51 min
Jun 18, 6:20 AM CDTSevere Thunderstorm WarningLSXClinton, Madison, Monroe, Randolph, Saint Clair, Washington40 min
Jun 18, 6:21 AM CDTTornado WarningLSXClinton, Monroe, Randolph, Saint Clair, Washington39 min
Jun 18, 6:51 AM CDTSevere Thunderstorm WarningLSXBond, Clinton, Fayette, Madison, Marion, Randolph and 2 more54 min
Jun 18, 7:24 AM CDTSevere Thunderstorm WarningLSXClinton, Marion30 min
Jun 18, 1:06 PM CDTAreal Flood WarningLSXMacoupin, Montgomery4 hr
Jun 18, 3:57 PM CDTFlash Flood WatchLSXBond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more15 hr
Jun 18, 4:49 PM CDTRiver Flood WarningLSXFayette5 days
Jun 18, 5:01 PM CDTAreal Flood WarningLSXMacoupin, Montgomery23 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.