Alert archive / Missouri / Flash Flood Watches in 2012

Flash Flood Watch 3, NWS St. Louis, MO

April 29, 201214 counties in Illinois; 20 counties in Missouri

NWS St. Louis, MO issued this flash flood watch at Apr 29, 2012, 4:00 PM CDT for 14 counties in Illinois; 20 counties in Missouri. It took effect at Apr 29, 2012, 10:00 PM CDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Apr 29, 2012, 4:00 PM CDT (21:00 UTC)
In effect from
Apr 29, 2012, 10:00 PM CDT
Expired
Apr 30, 2012, 7:08 AM CDT
In force
9 hr
Issued by
NWS St. Louis, MO
Flood severity
None
All 34 counties

Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Pike County, IL, Saint Clair County, IL, Washington County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 14 km from the middle of the area, began a volume at 21:01 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, 9.0 hours before the alert went out and 237 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.

973 
WGUS63 KLSX 292100
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
400 PM CDT SUN APR 29 2012

MOZ034>036-041-042-047>052-059-060-300900-
/O.NEW.KLSX.FF.A.0003.120430T0300Z-120430T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONROE MO-RALLS MO-PIKE MO-BOONE MO-AUDRAIN MO-MONITEAU MO-
COLE MO-OSAGE MO-CALLAWAY MO-MONTGOMERY MO-LINCOLN MO-
GASCONADE MO-WARREN MO-
INCLUDING THE CITIES OF...BOWLING GREEN...COLUMBIA...MEXICO...
JEFFERSON CITY
400 PM CDT SUN APR 29 2012

...FLASH FLOOD WATCH IN EFFECT FROM 10 PM CDT THIS EVENING
THROUGH MONDAY MORNING...

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL MISSOURI...EAST 
  CENTRAL MISSOURI AND NORTHEAST MISSOURI...INCLUDING THE 
  FOLLOWING COUNTIES...IN CENTRAL MISSOURI...AUDRAIN MO...BOONE 
  MO...CALLAWAY MO...COLE MO...MONITEAU MO AND OSAGE MO. IN 
  EAST CENTRAL MISSOURI...GASCONADE MO...LINCOLN MO...
  MONTGOMERY MO AND WARREN MO. IN NORTHEAST MISSOURI...MONROE 
  MO...PIKE MO AND RALLS MO.

* FROM 10 PM CDT THIS EVENING THROUGH MONDAY MORNING

* THUNDERSTORMS CONTAINING HEAVY RAIN WILL DEVELOP AND EXPAND OVER
  MUCH OF CENTRAL AND PARTS OF NORTHEAST MISSOURI BY LATER THIS
  EVENING AND CONTINUE OVERNIGHT AND INTO EARLY MONDAY MORNING
  BEFORE DIMINISHING OR MOVING TO THE EAST OF THE AREA. RAINFALL
  AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE...AND IF RECEIVED IN A
  SHORT ENOUGH TIME SPAN COULD LEAD TO FLASH FLOODING ON AREA
  CREEKS AND STREAMS SINCE MANY OF THESE SAME AREAS RECEIVED AN
  INCH OR SO OF RAINFALL THE PREVIOUS MORNING LEADING TO WET TO
  SATURATED GROUNDS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING IS POSSIBLE BUT NOT
IMMINENT IN THE WATCH AREA. PEOPLE IN THE WATCH AREA SHOULD BE
AWARE OF THE POSSIBILITY OF HEAVY RAINFALL AND FLASH FLOODING.
CHECK YOUR PREPAREDNESS REQUIREMENTS...ESPECIALLY IF YOU LIVE IN
FLOOD PRONE AREAS. STAY INFORMED...AND BE READY FOR QUICK ACTION
IF FLOODING IS OBSERVED OR IF A FLASH FLOOD WARNING IS ISSUED.

&&

$$

TES
2 follow-up statements
985 
WGUS63 KLSX 300641
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
141 AM CDT MON APR 30 2012

ILZ058>060-064-065-069-070-074-098>102-MOZ061>065-072-073-301700-
/O.EXB.KLSX.FF.A.0003.000000T0000Z-120430T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GREENE IL-MACOUPIN IL-MONTGOMERY IL-BOND IL-FAYETTE IL-CLINTON IL-
MARION IL-WASHINGTON IL-CALHOUN IL-JERSEY IL-MADISON IL-
ST. CLAIR IL-MONROE IL-ST. CHARLES MO-FRANKLIN MO-ST. LOUIS MO-
ST. LOUIS CITY MO-JEFFERSON MO-CRAWFORD MO-WASHINGTON MO-
INCLUDING THE CITIES OF...LITCHFIELD...VANDALIA...SALEM...
EDWARDSVILLE...BELLEVILLE...ST CHARLES...UNION...ST LOUIS
141 AM CDT MON APR 30 2012

...FLASH FLOOD WATCH IN EFFECT UNTIL NOON CDT TODAY...

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS EXPANDED THE

* FLASH FLOOD WATCH TO INCLUDE PORTIONS OF ILLINOIS AND EAST 
  CENTRAL MISSOURI...INCLUDING THE FOLLOWING COUNTIES...IN 
  ILLINOIS...BOND IL...CALHOUN IL...CLINTON IL...FAYETTE IL...
  GREENE IL...JERSEY IL...MACOUPIN IL...MADISON IL...MARION 
  IL...MONROE IL...MONTGOMERY IL...ST. CLAIR IL AND WASHINGTON 
  IL. IN EAST CENTRAL MISSOURI...CRAWFORD MO...FRANKLIN MO...
  JEFFERSON MO...ST. CHARLES MO...ST. LOUIS CITY MO...ST. LOUIS 
  MO AND WASHINGTON MO.

* UNTIL NOON CDT TODAY

* THUNDERSTORMS CONTAINING HEAVY RAIN WILL CONTINUE TO EXPAND OVER
  MUCH OF EASTERN AND SOUTHEAST MISSOURI AS WELL AS SOUTHWEST
  ILLINOIS INTO EARLY MONDAY MORNING. THESE THUNDERSTORMS ARE
  EXPECTED TO THEN DIMINISH OR MOVE TO THE EAST OF THE AREA BY NOON.
  RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE...AND IF RECEIVED
  IN A SHORT ENOUGH TIME SPAN COULD LEAD TO FLASH FLOODING ON AREA
  CREEKS AND STREAMS SINCE MANY OF THESE SAME AREAS RECEIVED AN
  INCH OR SO OF RAINFALL THE PREVIOUS MORNING LEADING TO WET TO
  SATURATED GROUNDS.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING IS POSSIBLE BUT NOT
IMMINENT IN THE WATCH AREA. PEOPLE IN THE WATCH AREA SHOULD BE
AWARE OF THE POSSIBILITY OF HEAVY RAINFALL AND FLASH FLOODING.
CHECK YOUR PREPAREDNESS REQUIREMENTS...ESPECIALLY IF YOU LIVE IN
FLOOD PRONE AREAS. STAY INFORMED...AND BE READY FOR QUICK ACTION
IF FLOODING IS OBSERVED OR IF A FLASH FLOOD WARNING IS ISSUED.

&&

$$

ILZ097-301500-
/O.EXA.KLSX.FF.A.0003.000000T0000Z-120430T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PIKE IL-
141 AM CDT MON APR 30 2012

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 AM CDT THIS MORNING...

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS EXPANDED THE

* FLASH FLOOD WATCH TO INCLUDE A PORTION OF WEST CENTRAL 
  ILLINOIS...INCLUDING THE FOLLOWING COUNTY...PIKE IL.

* UNTIL 10 AM CDT THIS MORNING

* THUNDERSTORMS CONTAINING HEAVY RAIN WILL CONTINUE TO DEVELOP AND
  EXPAND INTO PORTIONS OF WEST CENTRAL ILLINOIS INTO EARLY MONDAY
  MORNING BEFORE DIMINISHING OR MOVING TO THE EAST OF THE AREA BY
  MID MORNING. RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE...
  AND IF RECEIVED IN A SHORT ENOUGH TIME SPAN COULD LEAD TO FLASH
  FLOODING ON AREA CREEKS AND STREAMS SINCE MANY OF THESE SAME
  AREAS RECEIVED AN INCH OR SO OF RAINFALL THE PREVIOUS MORNING
  LEADING TO WET TO SATURATED GROUNDS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING IS POSSIBLE BUT NOT
IMMINENT IN THE WATCH AREA. PEOPLE IN THE WATCH AREA SHOULD BE
AWARE OF THE POSSIBILITY OF HEAVY RAINFALL AND FLASH FLOODING.
CHECK YOUR PREPAREDNESS REQUIREMENTS...ESPECIALLY IF YOU LIVE IN
FLOOD PRONE AREAS. STAY INFORMED...AND BE READY FOR QUICK ACTION
IF FLOODING IS OBSERVED OR IF A FLASH FLOOD WARNING IS ISSUED.

&&

$$

MOZ034>036-041-042-047>052-059-060-301500-
/O.CON.KLSX.FF.A.0003.000000T0000Z-120430T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONROE MO-RALLS MO-PIKE MO-BOONE MO-AUDRAIN MO-MONITEAU MO-
COLE MO-OSAGE MO-CALLAWAY MO-MONTGOMERY MO-LINCOLN MO-
GASCONADE MO-WARREN MO-
INCLUDING THE CITIES OF...BOWLING GREEN...COLUMBIA...MEXICO...
JEFFERSON CITY
141 AM CDT MON APR 30 2012

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 AM CDT THIS
MORNING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF CENTRAL MISSOURI...EAST CENTRAL MISSOURI AND 
  NORTHEAST MISSOURI...INCLUDING THE FOLLOWING COUNTIES...IN 
  CENTRAL MISSOURI...AUDRAIN MO...BOONE MO...CALLAWAY MO...COLE 
  MO...MONITEAU MO AND OSAGE MO. IN EAST CENTRAL MISSOURI...
  GASCONADE MO...LINCOLN MO...MONTGOMERY MO AND WARREN MO. IN 
  NORTHEAST MISSOURI...MONROE MO...PIKE MO AND RALLS MO.

* UNTIL 10 AM CDT THIS MORNING

* THUNDERSTORMS CONTAINING HEAVY RAIN WILL CONTINUE TO DEVELOP AND
  EXPAND OVER MUCH OF CENTRAL AND NORTHEAST MISSOURI INTO EARLY
  MONDAY MORNING BEFORE DIMINISHING OR MOVING TO THE EAST OF THE
  AREA BY MID MORNING. RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE
  POSSIBLE...AND IF RECEIVED IN A SHORT ENOUGH TIME SPAN COULD
  LEAD TO FLASH FLOODING ON AREA CREEKS AND STREAMS SINCE MANY OF
  THESE SAME AREAS RECEIVED AN INCH OR SO OF RAINFALL THE PREVIOUS
  MORNING LEADING TO WET TO SATURATED GROUNDS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING IS POSSIBLE BUT NOT
IMMINENT IN THE WATCH AREA. PEOPLE IN THE WATCH AREA SHOULD BE
AWARE OF THE POSSIBILITY OF HEAVY RAINFALL AND FLASH FLOODING.
CHECK YOUR PREPAREDNESS REQUIREMENTS...ESPECIALLY IF YOU LIVE IN
FLOOD PRONE AREAS. STAY INFORMED...AND BE READY FOR QUICK ACTION
IF FLOODING IS OBSERVED OR IF A FLASH FLOOD WARNING IS ISSUED.

&&

$$

TILLY
756 
WGUS63 KLSX 301208
FFALSX

FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
708 AM CDT MON APR 30 2012

ILZ058>060-064-065-069-070-074-098>102-MOZ061>065-072-073-301315-
/O.CAN.KLSX.FF.A.0003.000000T0000Z-120430T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GREENE IL-MACOUPIN IL-MONTGOMERY IL-BOND IL-FAYETTE IL-CLINTON IL-
MARION IL-WASHINGTON IL-CALHOUN IL-JERSEY IL-MADISON IL-
ST. CLAIR IL-MONROE IL-ST. CHARLES MO-FRANKLIN MO-ST. LOUIS MO-
ST. LOUIS CITY MO-JEFFERSON MO-CRAWFORD MO-WASHINGTON MO-
INCLUDING THE CITIES OF...LITCHFIELD...VANDALIA...SALEM...
EDWARDSVILLE...BELLEVILLE...ST CHARLES...UNION...ST LOUIS
708 AM CDT MON APR 30 2012

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF ILLINOIS AND EAST CENTRAL
MISSOURI HAS BEEN CANCELLED. THUNDERSTORMS OVERNIGHT BROUGHT AN
ADDITIONAL 1 TO 2 INCHES OF RAINFALL TO THE AREA WHICH CAUSED FLASH
FLOODING IN SOME AREAS. SINCE THEN...THE HEAVY RAIN THREAT HAS COME TO
AN END.

$$

ILZ097-MOZ034>036-041-042-047>052-059-060-301315-
/O.CAN.KLSX.FF.A.0003.000000T0000Z-120430T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PIKE IL-MONROE MO-RALLS MO-PIKE MO-BOONE MO-AUDRAIN MO-
MONITEAU MO-COLE MO-OSAGE MO-CALLAWAY MO-MONTGOMERY MO-LINCOLN MO-
GASCONADE MO-WARREN MO-
INCLUDING THE CITIES OF...BOWLING GREEN...COLUMBIA...MEXICO...
JEFFERSON CITY
708 AM CDT MON APR 30 2012

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF WEST CENTRAL ILLINOIS AND
MISSOURI HAS BEEN CANCELLED. THUNDERSTORMS OVERNIGHT BROUGHT AN
ADDITIONAL 2 TO 3 INCHES OF RAINFALL TO THE AREA WHICH CAUSED FLASH
FLOODING IN SOME AREAS. SINCE THEN...THE HEAVY RAIN THREAT HAS COME TO
AN END.

$$

TILLY

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, 7:54 AM CDTFlash Flood WarningLSXMacoupin, Montgomery6 hr
Apr 29, 7:58 AM CDTSevere Thunderstorm WarningLSXMontgomery20 min
Apr 29, 1:47 AM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole32 min
Apr 29, 2:22 AM CDTSevere Thunderstorm WarningLSXAudrain, Boone38 min
Apr 29, 2:52 AM CDTSevere Thunderstorm WarningLSXMonroe38 min
Apr 29, 3:05 AM CDTSevere Thunderstorm WarningLSXCallaway44 min
Apr 29, 4:00 AM CDTSevere Thunderstorm WarningLSXLincoln, Montgomery, Pike27 min

Nearby

Flash Flood Watches in Missouri, 2012Flash Flood Watches in Illinois, 2012Every flash flood watch 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.