Alert archive / Illinois / Flash Flood Warnings in 2012

Flash Flood Warning 15, NWS St. Louis, MO

April 29, 2012Macoupin County, Montgomery County, Illinois

NWS St. Louis, MO issued this flash flood warning at Apr 29, 2012, 7:54 AM CDT for Macoupin County, Montgomery County, Illinois. It was in force for 6 hr. 2 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 29, 2012, 7:54 AM CDT (12:54 UTC)
Expired
Apr 29, 2012, 2:00 PM CDT
In force
6 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), 97 km from the middle of the area, began a volume at 12:56 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 29, 9:24 AM CDTHEAVY RAIN 2.034 Nw Nokomis, IL24 HOUR TOTAL...WITH 1.16 OCCURRING IN THE PAST 90 MINUTES
Apr 29, 9:40 AM CDTHEAVY RAIN 2.25Nokomis, IL

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 12:00Z, 0.9 hours before the alert went out and 122 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 2012-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 2012-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
414 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

219 
WGUS53 KLSX 291254
FFWLSX
ILC117-135-291900-
/O.NEW.KLSX.FF.W.0015.120429T1254Z-120429T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
754 AM CDT SUN APR 29 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 200 PM CDT SUNDAY

* AT 753 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. RADAR AND SPOTTER REPORTS INDICATE TWO TO THREE 
  INCHES OF RAINFALL HAVE FALLEN THIS MORNING.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CARLINVILLE...GILLESPIE...HILLSBORO...LITCHFIELD...NOKOMIS...
  PALMYRA...RAYMOND...SHIPMAN...TAYLOR SPRINGS AND WITT.

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.

&&

LAT...LON 3922 8925 3911 8927 3911 9015 3944 9015
      3944 8953 3936 8952 3935 8922 3933 8915
      3922 8913

$$

TILLY
1 follow-up statement
723 
WGUS73 KLSX 291853
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
153 PM CDT SUN APR 29 2012

ILC117-135-291909-
/O.EXP.KLSX.FF.W.0015.000000T0000Z-120429T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MACOUPIN IL-MONTGOMERY IL-
153 PM CDT SUN APR 29 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR MONTGOMERY AND
CENTRAL MACOUPIN COUNTIES WILL BE ALLOWED TO EXPIRE AT 200 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.

LAT...LON 3922 8925 3911 8927 3911 9015 3944 9015
      3944 8953 3936 8952 3935 8922 3933 8915
      3922 8913

$$

BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 28, 7:41 PM CDTAreal Flood AdvisoryLSXClinton, Saint Clair, Washington6 hr
Apr 28, 8:12 PM CDTSevere Thunderstorm WarningLSXMonroe48 min
Apr 28, 8:39 PM CDTSevere Thunderstorm WarningLSXMonroe36 min
Apr 28, 9:05 PM CDTSevere Thunderstorm WarningLSXMonroe, Randolph, Saint Clair33 min
Apr 28, 9:31 PM CDTSevere Thunderstorm WarningLSXRandolph, Saint Clair, Washington33 min
Apr 28, 10:01 PM CDTSevere Thunderstorm WarningLSXBond, Macoupin, Madison, Montgomery34 min
Apr 28, 10:25 PM CDTSevere Thunderstorm WarningLSXMacoupin, Montgomery28 min
Apr 29, 1:44 AM CDTSevere Thunderstorm WarningLSXMadison46 min
Apr 29, 4:59 AM CDTSevere Thunderstorm WarningLSXCalhoun46 min
Apr 29, 5:32 AM CDTSevere Thunderstorm WarningLSXGreene, Jersey36 min
Apr 29, 7:58 AM CDTSevere Thunderstorm WarningLSXMontgomery20 min
Apr 29, 4:00 PM CDTFlash Flood WatchLSXBond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more15 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.