Alert archive / Missouri / Flash Flood Warnings in 2009

Flash Flood Warning 82, NWS St. Louis, MO

October 22, 2009Saint Louis County, Missouri

NWS St. Louis, MO issued this flash flood warning at Oct 22, 2009, 11:05 PM CDT for Saint Louis County, Missouri. 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: Oct 22, 2009, 11:05 PM CDT (04:05 UTC)
Expired: Oct 23, 2009, 5:00 AM CDT
In force: 6 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

County Saint Louis County, MO

The radar

The St Louis radar (KLSX), 23 km from the middle of the area, began a volume at 04:06 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

Time	Report	Where	Remark
Oct 22, 11:32 PM CDT	HEAVY RAIN 1.88	Ballwin, MO	1.88 INCHES OF RAIN SO FAR.
Oct 22, 11:53 PM CDT	HEAVY RAIN 2.1	Shrewsbury, MO	RAINFALL SO FAR.
Oct 23, 3:16 AM CDT	FLASH FLOOD	Clayton, MO	FLOODING WAS REPORTED ON HILLSBORO ROAD WEST OF MERAMAC STATION

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, 4.1 hours before the alert went out and 234 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 5 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 511 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 340 m²/s²
0-3 km storm-relative helicity: 412 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.

000 
WGUS53 KLSX 230405
FFWLSX
MOC189-231000-
/O.NEW.KLSX.FF.W.0082.091023T0405Z-091023T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1105 PM CDT THU OCT 22 2009

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 500 AM CDT

* AT 1101 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR 
  INDICATED AN AREA OF HEAVY RAINFALL ACROSS THE WARNED AREA... 
  WHERE RAINFALL AMOUNTS OF ONE TO TWO INCHES HAVE FALLEN ON 
  ALREADY SATURATED GROUND FROM VERY HEAVY RAINFALL LATE LAST WEEK 
  OR IN URBANIZED AREAS WHERE MUCH OF THE RAINFALL HAS TRANSLATED TO 
  RUNOFF. INDICATIONS ARE THAT SEVERAL SMALL AREA CREEKS ARE NEARING 
  BANKFULL AND GETTING READY TO FLOOD NEARBY LAND. SOME OF THESE 
  CREEKS ARE SUGAR CREEK IN KIRKWOOD AND CREEKS IN THE LADUE AREA. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  AFFTON...BALLWIN...BEL-RIDGE...BELLEFONTAINE NEIGHBORS...
  BERKELEY...BLACK JACK...BRENTWOOD...BRIDGETON...CHESTERFIELD...
  CLARKSON VALLEY...CLAYTON...COOL VALLEY...CRESTWOOD...CREVE
  COEUR...DELLWOOD...DES PERES...ELLISVILLE...EUREKA...FENTON...
  FERGUSON...FLORISSANT...FRONTENAC...GLENDALE...HAZELWOOD...
  HILLSDALE...JENNINGS...KINLOCH...KIRKWOOD...LADUE AND LAKESHIRE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF UP TO ONE HALF INCH ARE POSSIBLE IN 
THE WARNED AREA WHICH WILL FURTHER AGGRAVATE OR ADD TO THE FLOODING. 

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY 
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN ST 
LOUIS.

&&

LAT...LON 3867 9031 3858 9032 3852 9026 3839 9034
      3845 9034 3846 9041 3850 9041 3850 9059
      3847 9061 3847 9066 3844 9067 3846 9074
      3863 9074 3868 9067 3869 9055 3883 9045
      3883 9037 3889 9031 3883 9021 3881 9012

$$

TES

1 follow-up statement

000 
WGUS73 KLSX 230813
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
313 AM CDT FRI OCT 23 2009

MOC189-231000-
/O.CON.KLSX.FF.W.0082.000000T0000Z-091023T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ST. LOUIS MO-
313 AM CDT FRI OCT 23 2009

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR ST. LOUIS COUNTY UNTIL 
500 AM CDT...

AT 306 AM CDT...EVEN THOUGH THE HEAVY RAINFALL HAS ENDED WITH ONLY 
LINGERING LIGHT RAIN...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THAT 
FLASH FLOODING WAS STILL OCCURRING ON HILLSBORO ROAD WEST OF MERAMAC 
STATION. THE WATER WAS RECEEDING ON MOST AREA ROADS. INDICATIONS ARE 
THAT SEVERAL SMALL AREA CREEKS ARE NEAR BANKFULL AND MAY BE CAUSING 
SOME FLOODING OF NEARBY LAND. SOME OF THESE CREEKS ARE SUGAR CREEK 
IN KIRKWOOD AND CREEKS IN THE LADUE AREA. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO   
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... 
AFFTON...BALLWIN...BEL-RIDGE...BELLEFONTAINE NEIGHBORS... 
BERKELEY...BLACK JACK...BRENTWOOD...BRIDGETON...CHESTERFIELD 
...CLARKSON VALLEY...CLAYTON...COOL VALLEY...CRESTWOOD...CREVE 
COEUR...DELLWOOD...DES PERES...ELLISVILLE...EUREKA...FENTON... 
FERGUSON...FLORISSANT...FRONTENAC...GLENDALE...HAZELWOOD...JENNINGS 
...KINLOCH...KIRKWOOD...LADUE...LAKESHIRE AND LEMAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

REPORT FLOODING TO THE NEAREST LAW ENFORCEMENT AGENCY SO THAT THEY
MAY TAKE APPROPRIATE ACTION TO CLOSE FLOODED ROADWAYS. THEY WILL
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN ST LOUIS.

&&

LAT...LON 3867 9031 3858 9032 3852 9026 3839 9034
      3845 9034 3846 9041 3850 9041 3850 9059
      3847 9061 3847 9066 3844 9067 3846 9074
      3863 9074 3868 9067 3869 9055 3883 9045
      3883 9037 3889 9031 3883 9021 3881 9012

$$

GKS

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 22, 8:11 PM CDT	River Flood Warning	LSX	Lewis	60 hr
Oct 22, 9:01 PM CDT	River Flood Warning	LSX	Marion	59 hr
Oct 22, 9:01 PM CDT	River Flood Warning	LSX	Marion	18 hr
Oct 22, 10:06 PM CDT	Areal Flood Advisory	LSX	Crawford, Franklin, Iron, Jefferson, Madison, Reynolds and 6 more	5 hr
Oct 23, 12:57 AM CDT	Areal Flood Warning	LSX	Audrain, Boone, Callaway, Cole, Knox, Moniteau and 2 more	9 hr
Oct 23, 5:06 AM CDT	Areal Flood Warning	LSX	Saint Louis	5 hr
Oct 23, 5:54 AM CDT	River Flood Warning	LSX	Reynolds	26 hr
Oct 23, 7:21 AM CDT	River Flood Warning	LSX	Lincoln	25 hr
Oct 23, 9:51 AM CDT	River Flood Warning	LSX	Jefferson	25 hr
Oct 23, 10:02 AM CDT	Areal Flood Warning	LSX	Knox, Monroe, Shelby	24 hr
Oct 23, 10:07 AM CDT	Areal Flood Warning	LSX	Boone	6 hr
Oct 23, 10:13 AM CDT	Areal Flood Warning	LSX	Saint Louis	24 hr
Oct 23, 11:49 AM CDT	River Flood Warning	LSX	Cole	9 hr

Nearby

Flash Flood Warnings in Missouri, 2009 Every flash flood warning in 2009

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.