Alert archive / Missouri / Flash Flood Warnings in 2009

Flash Flood Warning 67, NWS St. Louis, MO

August 17, 2009Shelby County, Missouri

NWS St. Louis, MO issued this flash flood warning at Aug 17, 2009, 11:44 AM CDT for Shelby County, Missouri. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 17, 2009, 11:44 AM CDT (16:44 UTC)
Expired
Aug 17, 2009, 5:30 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Shelby County, MO

The radar

The St Louis radar (KLSX), 169 km from the middle of the area, began a volume at 16:45 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

Davenport, (KDVN), launched 12:00Z, 4.7 hours before the alert went out and 245 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, Davenport, at 12:00Z on 2009-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 64 joules per kilogram.LCLLFCEL10008507005003002001001 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, Davenport, at 12:00Z on 2009-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -88 square meters per square second.193958Sfc1 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
64 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
616 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-88 m²/s²
0-3 km storm-relative helicity
-20 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 171644
FFWLSX
MOC205-172230-
/O.NEW.KLSX.FF.W.0067.090817T1644Z-090817T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1144 AM CDT MON AUG 17 2009

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SHELBY COUNTY IN NORTHEAST MISSOURI...

* UNTIL 530 PM CDT

* AT 1140 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE
  WARNED AREA. THE RAINFALL FROM THE STORMS OF LATE THIS MORNING HAS
  COMBINED WITH THE WET WEATHER OF SUNDAY AND SUNDAY NIGHT TO PRODUCE
  FLASH FLOODING.  HIGHWAY DD AT MAUD IS NOW CLOSED...AS WELL AS 
  HIGHWAY A SOUTH OF LENTNER.  IN ADDITION...FLOODING HAS BEGUN
  TO THREATEN HIGHWAY 36 ONE AND ONE-HALF MILES WEST OF
  HIGHWAY TT...BETWEEN CLARENCE AND LENTER.     

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  SHELBINA...CLARENCE...EMDEN...MAUD AND SHELBYVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS... OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING
STREAM... EVEN A SMALL ONE...ON FOOT OR IN A VEHICLE.

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

&&

LAT...LON 3995 9185 3966 9186 3966 9219 3961 9220
      3961 9230 3995 9229

$$

TRUETT
1 follow-up statement
000 
WGUS73 KLSX 171851
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
151 PM CDT MON AUG 17 2009

MOC205-172230-
/O.CON.KLSX.FF.W.0067.000000T0000Z-090817T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SHELBY MO-
151 PM CDT MON AUG 17 2009

...FLASH FLOOD WARNING FOR REMAINS IN EFFECT FOR SHELBY COUNTY UNTIL
530 PM CDT...

AT 147 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT RAIN AND SCATTERED THUNDERSTORMS WILL CONTINUE ACROSS THE AREA 
THROUGH 4 PM.  FLASH FLOODING HAS ALREADY BEEN REPORTED...ESPECIALLY 
IN SOUTHERN SECTIONS OF THE COUNTY...AND THIS ADDITIONAL HEAVY RAIN 
WILL ENHANCE THE FLASH FLOOD THREAT THROUGHOUT THE AFTERNOON.  

ADDITIONAL RAINS OF ONE-HALF TO ONE INCH WILL BE POSSIBLE THROUGH 4 
PM.  

RUNOFF FROM THIS RAINFALL WILL CONTINUE THE FLASH FLOODING THREAT 
ACROSS THE COUNTY.  SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...SHELBINA...CLARENCE...EMDEN...MAUD AND SHELBYVILLE.

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.

THERE ARE DOZENS OF LOW WATER CROSSINGS WHICH ARE POTENTIALLY 
DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS FLOODED 
ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW INCHES OF SWIFTLY 
FLOWING WATER TO CARRY VEHICLES AWAY.

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 3995 9185 3966 9186 3966 9219 3961 9220
      3961 9230 3995 9229

$$

TRUETT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 11:54 PM CDTFlash Flood WarningLSXKnox6 hr
Aug 17, 1:57 AM CDTFlash Flood WarningLSXKnox, Lewis, Marion, Monroe, Shelby4 hr
Aug 17, 4:09 AM CDTFlash Flood WatchLSXKnox, Lewis, Marion, Monroe, Pike, Ralls and 1 more11 hr
Aug 17, 2:16 PM CDTAreal Flood AdvisoryLSXKnox, Lewis, Marion, Monroe, Ralls5 hr
Aug 17, 3:10 PM CDTRiver Flood WarningLSXLewis28 hr
Aug 17, 5:14 PM CDTAreal Flood AdvisoryLSXSaint Charles, Saint Louis, City of Saint Louis6 hr
Aug 17, 5:28 PM CDTAreal Flood WarningLSXShelby12 hr

Nearby

Flash Flood Warnings in Missouri, 2009Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.