Alert archive / Missouri / Flash Flood Warnings in 2011

Flash Flood Warning 7, NWS St. Louis, MO

April 22, 2011Franklin County, Jefferson County, Saint Louis County, Missouri

NWS St. Louis, MO issued this flash flood warning at Apr 22, 2011, 9:00 PM CDT for Franklin County, Jefferson County, Saint Louis County, Missouri. It was in force for 5 hr. 1 report 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 22, 2011, 9:00 PM CDT (02:00 UTC)
Expired: Apr 23, 2011, 2:00 AM CDT
In force: 5 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

Counties Franklin County, MO, Jefferson County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 30 km from the middle of the area, began a volume at 02:03 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
Apr 22, 9:14 PM CDT	FLASH FLOOD	1 Sw Fenton, MO	FLOODING BY CREEK...SOME HOUSES SURROUNDED BY 2-6 INCHES OF STANDING WATER

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, 2.0 hours before the alert went out and 267 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: 342 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 492 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 351 m²/s²
0-3 km storm-relative helicity: 346 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

549 
WGUS53 KLSX 230200
FFWLSX
MOC071-099-189-230700-
/O.NEW.KLSX.FF.W.0007.110423T0200Z-110423T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
900 PM CDT FRI APR 22 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL FRANKLIN COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  SOUTHERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 200 AM CDT

* AT 859 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS HAD PRODUCED VERY HEAVY RAIN OVER THE AREA
  SINCE 5 PM.  RAINFALLS IN EXCESS OF 2 INCHES HAVE BEEN REPORTED
  IN GRAYS SUMMIT...AND AROUND A FOOT OF WATER WAS OVER A ROAD IN A
  SUBDIVISION IN GRAYS SUMMIT.   

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ANTONIA...ARNOLD...BARNHART...BYRNES MILL...CEDAR HILL...EUREKA...
  FENTON...GRAY SUMMIT...HIGH RIDGE...LEMAY...MEHLVILLE...MURPHY...
  OAKVILLE...PACIFIC...ST. CLAIR...SUNSET HILLS...UNION...VILLA
  RIDGE...BEAUFORT...DITTMER...GERALD...HOUSE SPRINGS AND PARKWAY.

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.

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

&&

LAT...LON 3854 9137 3853 9026 3845 9030 3837 9036
      3834 9037 3829 9137

$$

TRUETT

1 follow-up statement

517 
WGUS73 KLSX 230656
FFSLSX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
156 AM CDT SAT APR 23 2011

MOC071-099-189-230711-
/O.EXP.KLSX.FF.W.0007.000000T0000Z-110423T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JEFFERSON MO-FRANKLIN MO-ST. LOUIS MO-
156 AM CDT SAT APR 23 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN ST.
LOUIS...CENTRAL FRANKLIN AND NORTHERN JEFFERSON COUNTIES WILL BE
ALLOWED TO EXPIRE AT 200 AM 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 3854 9137 3853 9026 3845 9030 3837 9036
      3834 9037 3829 9137

$$

BYRD

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 22, 7:11 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Gasconade, Saint Charles, Warren	49 min
Apr 22, 7:20 PM CDT	Tornado Warning	LSX	Franklin, Gasconade, Saint Charles	40 min
Apr 22, 7:36 PM CDT	Tornado Warning	LSX	Saint Charles, Saint Louis	39 min
Apr 22, 7:44 PM CDT	Tornado Warning	LSX	Reynolds	16 min
Apr 22, 7:56 PM CDT	Tornado Warning	LSX	Franklin, Jefferson, Saint Louis	42 min
Apr 22, 7:59 PM CDT	Tornado Warning	LSX	Saint Louis, City of Saint Louis	46 min
Apr 22, 8:21 PM CDT	Tornado Warning	LSX	Jefferson, Saint Louis	39 min
Apr 22, 10:18 PM CDT	River Flood Warning	LSX	Jefferson	8 days
Apr 22, 10:55 PM CDT	Flash Flood Warning	LSX	Crawford, Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois and 1 more	6 hr
Apr 22, 11:10 PM CDT	River Flood Warning	LSX	Lewis	25 hr
Apr 22, 11:12 PM CDT	Tornado Warning	LSX	Iron, Madison, Sainte Genevieve, Saint Francois	37 min
Apr 22, 11:53 PM CDT	River Flood Warning	LSX	Saint Louis, City of Saint Louis	14 days
Apr 23, 1:21 AM CDT	Severe Thunderstorm Warning	LSX	Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois	30 min
Apr 23, 1:47 AM CDT	River Flood Warning	LSX	Gasconade, Montgomery	9 days
Apr 23, 4:23 AM CDT	Flash Flood Warning	LSX	Crawford, Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois and 1 more	8 hr
Apr 23, 6:45 AM CDT	River Flood Warning	LSX	Lewis	39 hr
Apr 23, 12:29 PM CDT	Flash Flood Warning	LSX	Crawford, Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois and 1 more	6 hr
Apr 23, 4:59 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	46 min
Apr 23, 5:27 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Washington	48 min
Apr 23, 5:41 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Jefferson, Washington	33 min
Apr 23, 6:22 PM CDT	Flash Flood Warning	LSX	Crawford, Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois and 1 more	6 hr

Nearby

Flash Flood Warnings in Missouri, 2011 Every flash flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.