Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 53, NWS St. Louis, MO

June 18, 2011Macoupin County, Montgomery County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 18, 2011, 1:14 AM CDT for Macoupin County, Montgomery County, Illinois. It was in force for 12 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, 1:14 AM CDT (06:14 UTC)
Expired
Jun 18, 2011, 1:00 PM CDT
In force
12 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Macoupin County, IL, Montgomery County, IL

The radar

The Lincoln radar (KILX), 91 km from the middle of the area, began a volume at 06:16 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, 4:10 AM CDTFLASH FLOODRaymond, ILVIADUCT FLOODED IN TOWN TO A DEPTH OF 3 TO 4 FEET.
Jun 18, 6:00 AM CDTFLASH FLOODVirden, ILLOTS OF COUNTY ROADS FLOODED NEAR VIRDEN.
Jun 18, 12:56 PM CDTFLOODVirden, ILSEVERAL SECONDARY ROADS NEAR VIRDEN REMAIN FLOODED.

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, 6.2 hours before the alert went out and 125 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.

794 
WGUS53 KLSX 180614
FFWLSX
ILC117-135-181200-
/O.NEW.KLSX.FF.W.0053.110618T0614Z-110618T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...
  NORTHERN MONTGOMERY COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 700 AM CDT

* AT 113 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 HAVE ALREADY FALLEN ACROSS 
  PORTIONS OF THE WARNED AREA. ANOTHER TWO INCHES IS EXPECTED WITH 
  THESE THUNDERSTORMS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CARLINVILLE...NOKOMIS...VIRDEN...FARMERSVILLE...GIRARD...PALMYRA...
  RAYMOND...WHITE OAK AND WITT.

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 3925 8986 3940 9004 3953 9005 3953 8954
      3936 8952 3936 8915 3922 8913

$$

TILLY
1 follow-up statement
611 
WGUS53 KLSX 181155
FFWLSX
ILC117-135-181800-
/O.EXT.KLSX.FF.W.0053.000000T0000Z-110618T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  NORTHERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...
  NORTHERN MONTGOMERY COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 100 PM CDT SATURDAY

* AT 652 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THAT 
  NUMEROUS ROADS WERE FLOODED NEAR VIRDEN. AFTER RECEIVING TWO TO 
  THREE INCHES OF RAINFALL EARLY THIS MORNING...ANOTHER LINE OF 
  THUNDERSTORMS CAPABLE OF PRODUCING AN ADDITIONAL ONE TO TWO 
  INCHES OF RAIN WILL MOVE OVER THE SAME AREAS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CARLINVILLE...NOKOMIS...VIRDEN...FARMERSVILLE...GIRARD...PALMYRA...
  RAYMOND...WHITE OAK AND WITT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3925 8986 3940 9004 3953 9005 3953 8954
      3936 8952 3936 8915 3922 8913

$$

TILLY

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, 1:16 AM CDTSevere Thunderstorm WarningLSXMacoupin, Montgomery29 min
Jun 18, 2:51 AM CDTFlash Flood WarningLSXFayette, Montgomery6 hr
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.