Alert archive / Illinois / Flash Flood Watches in 2011

Flash Flood Watch 3, NWS St. Louis, MO

May 1, 20118 counties in Illinois; 8 counties in Missouri

NWS St. Louis, MO issued this flash flood watch at May 1, 2011, 4:30 AM CDT for 8 counties in Illinois; 8 counties in Missouri. It took effect at May 1, 2011, 7:00 PM CDT. It was in force for 28 hr.

The area

The counties it named.

The facts

Issued
May 1, 2011, 4:30 AM CDT (09:30 UTC)
In effect from
May 1, 2011, 7:00 PM CDT
Expired
May 2, 2011, 10:55 PM CDT
In force
28 hr
Issued by
NWS St. Louis, MO
Flood severity
None

Counties Bond County, IL, Clinton County, IL, Fayette County, IL, Marion County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, Crawford County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Reynolds County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 79 km from the middle of the area, began a volume at 09:28 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 00:00Z, 9.5 hours before the alert went out and 256 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 2011-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2011-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 218 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1530 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
218 m²/s²
0-3 km storm-relative helicity
230 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.

612 
WGUS63 KLSX 010930
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
430 AM CDT SUN MAY 1 2011

...ANOTHER ROUND OF HEAVY RAINFALL POSSIBLE TONIGHT...

.A COLD FRONT WILL STALL ACROSS THE LOWER MISSISSIPPI AND OHIO
RIVER VALLEYS TODAY. RAIN AND THUNDERSTORMS WILL DEVELOP ALONG AND
NORTH OF THE FRONT THIS AFTERNOON AND TONIGHT. SOME OF THE HEAVIER
RAIN WILL IMPACT SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS TONIGHT.
THESE ARE THE SAME AREAS WHICH RECEIVED BETWEEN 7 AND 12 INCHES OF
RAIN LAST WEEK...AND ANY ADDITIONAL RAINFALL WILL ONLY WORSEN
ONGOING FLOODING AND COULD CAUSE ADDITIONAL FLASH FLOODING.

ILZ064-065-069-070-074-079-101-102-MOZ065-072>075-084-085-099-
012215-
/O.NEW.KLSX.FF.A.0003.110502T0000Z-110502T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOND IL-FAYETTE IL-CLINTON IL-MARION IL-WASHINGTON IL-RANDOLPH IL-
ST. CLAIR IL-MONROE IL-JEFFERSON MO-CRAWFORD MO-WASHINGTON MO-
ST. FRANCOIS MO-STE. GENEVIEVE MO-IRON MO-MADISON MO-REYNOLDS MO-
INCLUDING THE CITIES OF...VANDALIA...SALEM...CHESTER...
BELLEVILLE...FARMINGTON
430 AM CDT SUN MAY 1 2011

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF ILLINOIS AND MISSOURI...
  INCLUDING THE FOLLOWING COUNTIES...IN ILLINOIS...BOND IL...
  CLINTON IL...FAYETTE IL...MARION IL...MONROE IL...RANDOLPH 
  IL...ST. CLAIR IL AND WASHINGTON IL. IN MISSOURI...CRAWFORD 
  MO...IRON MO...JEFFERSON MO...MADISON MO...REYNOLDS MO...ST. 
  FRANCOIS MO...STE. GENEVIEVE MO AND WASHINGTON MO.

* FROM THIS EVENING THROUGH MONDAY MORNING

* RAINFALL BETWEEN 0.5 AND 1.5 INCHES IS LIKELY THROUGH TONIGHT.
  LOCALLY HIGHER AMOUNTS ARE POSSIBLE.

* RAINFALL ON ALREADY SATURATED GROUND WILL RUN OFF AND QUICKLY
  CAUSE FLASH FLOODING. ADDITIONALLY...ANY RAINFALL THAT OCCURS
  WILL EXTEND AND OR WORSEN ONGOING FLOODING ACROSS THE AREA.

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.

&&

$$

CARNEY
4 follow-up statements
139 
WGUS63 KLSX 012015
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
315 PM CDT SUN MAY 1 2011

...ANOTHER ROUND OF HEAVY RAINFALL POSSIBLE TONIGHT THROUGH MONDAY...

.A COLD FRONT WILL REMAIN STALLED ACROSS THE LOWER MISSISSIPPI AND
OHIO RIVER VALLEYS THROUGH TOMORROW. RAIN AND THUNDERSTORMS HAVE
DEVELOPED ALONG AND NORTH OF THE FRONT THIS AFTERNOON AND WILL
CONTINUE THROUGH MONDAY. SOME OF THE HEAVIER RAIN WILL IMPACT
SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS THROUGH MONDAY. THESE ARE
THE SAME AREAS WHICH RECEIVED BETWEEN 7 AND 12 INCHES OF RAIN
LAST WEEK...AND ANY ADDITIONAL RAINFALL WILL ONLY WORSEN ONGOING
FLOODING AND COULD CAUSE ADDITIONAL FLASH FLOODING.

ILZ064-065-069-070-101-102-MOZ065-012115-
/O.CAN.KLSX.FF.A.0003.110502T0000Z-110502T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BOND IL-FAYETTE IL-CLINTON IL-MARION IL-ST. CLAIR IL-MONROE IL-
JEFFERSON MO-
INCLUDING THE CITIES OF...VANDALIA...SALEM...BELLEVILLE
315 PM CDT SUN MAY 1 2011

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF ILLINOIS AND EAST CENTRAL
MISSOURI HAS BEEN CANCELLED. THE THREAT OF HEAVY CONVECTIVE
RAINFALL WILL BE FURTHER TO THE SOUTH...THEREFORE THE FLASH FLOOD
WATCH IS CANCELLED.

$$

ILZ074-079-MOZ072>075-084-085-099-021000-
/O.EXT.KLSX.FF.A.0003.110502T0000Z-110503T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON IL-RANDOLPH IL-CRAWFORD MO-WASHINGTON MO-
ST. FRANCOIS MO-STE. GENEVIEVE MO-IRON MO-MADISON MO-REYNOLDS MO-
INCLUDING THE CITIES OF...CHESTER...FARMINGTON
315 PM CDT SUN MAY 1 2011

...FLASH FLOOD WATCH NOW IN EFFECT FROM 7 PM CDT THIS EVENING
THROUGH MONDAY EVENING...

THE FLASH FLOOD WATCH IS NOW IN EFFECT FOR

* PORTIONS OF ILLINOIS AND MISSOURI...INCLUDING THE FOLLOWING 
  COUNTIES...IN ILLINOIS...RANDOLPH IL AND WASHINGTON IL. IN 
  MISSOURI...CRAWFORD MO...IRON MO...MADISON MO...REYNOLDS MO...
  ST. FRANCOIS MO...STE. GENEVIEVE MO AND WASHINGTON MO.

* FROM 7 PM CDT THIS EVENING THROUGH MONDAY EVENING

* RAINFALL BETWEEN HALF AN INCH AND ONE AND A HALF INCHES IS
  LIKELY THROUGH MONDAY. LOCALLY HIGHER AMOUNTS ARE POSSIBLE.

* RAINFALL ON ALREADY SATURATED GROUND WILL RUN OFF AND QUICKLY 
  CAUSE FLASH FLOODING. ADDITIONALLY...ANY RAINFALL THAT OCCURS 
  WILL EXTEND AND OR WORSEN ONGOING FLOODING ACROSS THE AREA. 

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.

&&

$$

BYRD
174 
WGUS63 KLSX 020910
FFALSX

FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
410 AM CDT MON MAY 2 2011

...THREAT FOR HEAVY RAIN AND FLASH FLOODING CONTINUES TODAY...

SHOWERS AND THUNDERSTORMS ARE LIKELY AGAIN TODAY...PRIMARILY IN
THE AFTERNOON...ACROSS PARTS OF SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS. THE GROUND IS ALREADY SATURATED...AND ANY ADDITIONAL
RAINFALL WILL RUNOFF IMMEDIATELY.

MOZ072-073-021015-
/O.CAN.KLSX.FF.A.0003.000000T0000Z-110503T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CRAWFORD MO-WASHINGTON MO-
410 AM CDT MON MAY 2 2011

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR A PORTION OF EAST CENTRAL MISSOURI HAS
BEEN CANCELLED. THE THREAT FOR HEAVY RAIN HAS SHIFTED TO THE
SOUTHEAST AWAY FROM CRAWFORD AND WASHINGTON COUNTIES TODAY.
THEREFORE THE FLASH FLOOD WATCH HAS BEEN CANCELLED.

$$

ILZ074-079-MOZ074-075-084-085-099-030000-
/O.CON.KLSX.FF.A.0003.000000T0000Z-110503T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON IL-RANDOLPH IL-ST. FRANCOIS MO-STE. GENEVIEVE MO-
IRON MO-MADISON MO-REYNOLDS MO-
INCLUDING THE CITIES OF...CHESTER...FARMINGTON
410 AM CDT MON MAY 2 2011

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF ILLINOIS AND SOUTHEAST MISSOURI...INCLUDING THE 
  FOLLOWING COUNTIES...IN ILLINOIS...RANDOLPH IL AND WASHINGTON 
  IL. IN SOUTHEAST MISSOURI...IRON MO...MADISON MO...REYNOLDS 
  MO...ST. FRANCOIS MO AND STE. GENEVIEVE MO.

* UNTIL 700 PM CDT

* RAINFALL BETWEEN ONE HALF AND ONE INCH WILL BE POSSIBLE ACROSS
  THE WATCH AREA TODAY...PRIMARILY IN THE AFTERNOON. 

* RAINFALL ON ALREADY SATURATED GROUND WILL RUN OFF AND QUICKLY 
  CAUSE FLASH FLOODING. ADDITIONALLY...ANY RAINFALL THAT OCCURS 
  WILL EXTEND AND OR WORSEN ONGOING FLOODING ACROSS THE AREA. 

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.

&&

$$

CARNEY
028 
WGUS63 KLSX 022047
FFALSX

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
347 PM CDT MON MAY 2 2011

...THREAT FOR HEAVY RAIN AND FLASH FLOODING CONTINUES TONIGHT...

SHOWERS ARE LIKELY AGAIN TONIGHT ACROSS PARTS OF SOUTHEAST MISSOURI
AND SOUTHWEST ILLINOIS. THE GROUND IS ALREADY SATURATED...AND ANY
ADDITIONAL RAINFALL WILL RUNOFF IMMEDIATELY.

ILZ074-079-MOZ074-075-084-085-099-031000-
/O.EXT.KLSX.FF.A.0003.000000T0000Z-110503T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON IL-RANDOLPH IL-ST. FRANCOIS MO-STE. GENEVIEVE MO-
IRON MO-MADISON MO-REYNOLDS MO-
INCLUDING THE CITIES OF...CHESTER...FARMINGTON
347 PM CDT MON MAY 2 2011

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH LATE TONIGHT...

THE FLASH FLOOD WATCH IS NOW IN EFFECT FOR

* PORTIONS OF SOUTHWEST ILLINOIS AND SOUTHEAST MISSOURI...INCLUDING
  THE FOLLOWING COUNTIES...IN SOUTHWEST ILLINOIS...RANDOLPH IL AND
  WASHINGTON IL. IN SOUTHEAST MISSOURI...IRON MO...MADISON
  MO...REYNOLDS MO...ST. FRANCOIS MO AND STE. GENEVIEVE MO.

* THROUGH LATE TONIGHT

* RAINFALL BETWEEN ONE HALF AND ONE INCH IS EXPECTED ACROSS THE
  WATCH AREA TONIGHT...PRIMARILY THIS EVENING.

* RAINFALL ON ALREADY SATURATED GROUND WILL RUN OFF AND QUICKLY 
  CAUSE FLASH FLOODING. ADDITIONALLY...ANY RAINFALL THAT OCCURS 
  WILL EXTEND AND OR WORSEN ONGOING FLOODING ACROSS THE AREA. 

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.

&&

$$

GKS
589 
WGUS63 KLSX 030355
FFALSX

FLOOD WATCH
NATIONAL WEATHER SERVICE ST LOUIS MO
1055 PM CDT MON MAY 2 2011

ILZ074-079-MOZ074-075-084-085-099-030500-
/O.CAN.KLSX.FF.A.0003.000000T0000Z-110503T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON IL-RANDOLPH IL-ST. FRANCOIS MO-STE. GENEVIEVE MO-
IRON MO-MADISON MO-REYNOLDS MO-
INCLUDING THE CITIES OF...CHESTER...FARMINGTON
1055 PM CDT MON MAY 2 2011

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF ILLINOIS AND SOUTHEAST
MISSOURI HAS BEEN CANCELLED. ONLY LIGHT RAIN IS EXPECTED FOR THE
REMAINDER OF THE NIGHT WITH ANY ADDITIONAL RAINFALL REMAINING LESS
THAN A TENTH OF AN INCH. 

$$

TES

Nearby

Flash Flood Watches in Illinois, 2011Flash Flood Watches in Missouri, 2011Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.