Alert archive / Alabama / Flash Flood Warnings in 2011

Flash Flood Warning 62, NWS Birmingham, AL

September 20, 20114 counties in Alabama

NWS Birmingham, AL issued this flash flood warning at Sep 20, 2011, 1:15 PM CDT for 4 counties in Alabama. It was in force for 3 hr. 5 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
Sep 20, 2011, 1:15 PM CDT (18:15 UTC)
Expired
Sep 20, 2011, 4:00 PM CDT
In force
3 hr
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Flood severity
None

Counties Blount County, AL, Jefferson County, AL, Shelby County, AL, St. Clair County, AL

The radar

The Birmingham radar (KBMX), 63 km from the middle of the area, began a volume at 18:16 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

TimeReportWhereRemark
Sep 20, 1:55 PM CDTFLASH FLOOD1 Ssw Allgood, ALWATER FLOWING ACROSS 270 TIDWELL HOLLOW ROAD. ROAD IS IMPASSABLE.
Sep 20, 2:00 PM CDTFLASH FLOOD1 Sw Remlap, ALWATER FLOWING OUT OF SMALL CREEK AND BEGINNING TO FLOW ONTO STATE HIGHWAY 75 AT SOUTHEASTERN ELEMENTARY SCHOOL IN REMLAP.
Sep 20, 2:02 PM CDTFLASH FLOOD1 Nnw Remlap, ALWATER OVER ROADWAY ON HOUSE ROAD NEAR REMLAP.
Sep 20, 2:02 PM CDTFLASH FLOODLocust Fork, ALWATER OVER ROADWAY ALONG SPUNKY HOLLOW ROAD IN LOCUST FORK.
Sep 20, 2:10 PM CDTFLASH FLOOD2 Ne Remlap, ALFLASH FLOODING ON REMLAP DRIVE BETWEEN VALLEY GROVE ROAD AND STATE HIGHWAY 75 SOUTH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 6.3 hours before the alert went out and 62 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, Birmingham, AL at 12:00Z on 2011-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 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, Birmingham, AL at 12:00Z on 2011-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.1939Sfc1 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
42 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
104 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.

709 
WGUS54 KBMX 201815
FFWBMX
ALC009-073-115-117-202100-
/O.NEW.KBMX.FF.W.0062.110920T1815Z-110920T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
115 PM CDT TUE SEP 20 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN JEFFERSON COUNTY IN ALABAMA...
  NORTH CENTRAL SHELBY COUNTY IN ALABAMA...
  SOUTHERN BLOUNT COUNTY IN ALABAMA...
  WEST CENTRAL ST. CLAIR COUNTY IN ALABAMA...

* UNTIL 400 PM CDT

* AT 114 PM CDT...NATIONAL WEATHER SERVICE INDICATED SLOW MOVING     
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BIRMINGHAM...CLEVELAND...FULTONDALE...GARDENDALE...HOMEWOOD...
  IRONDALE...LEEDS...MOODY...MOUNTAIN BROOK...ONEONTA...
  PINSON-CLAY-CHALKVILLE...SPRINGVILLE...TRUSSVILLE...VESTAVIA
  HILLS...ALLGOOD...ALTON...ARGO...B.J.C.C....BARBER MOTORSPORTS
  PARK...BIRMINGHAM AIRPORT...BLUFF PARK...CAHABA HEIGHTS...CENTER
  POINT...CLAY...COUNTY LINE...DALLAS...FAIRVIEW...FOWLER LAKE...
  GREYSTONE AND KETONA LAKES.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. RAINFALL FROM PERSISTENT RAINBANDS
WILL PRODUCE FLOODING IN LOW LYING AREAS AND ALONG STREETS. MANY
ROADS WILL BE CLOSED DUE TO HIGH WATER AND DRIVING IS NOT RECOMMENDED
DURING THE NEXT SEVERAL HOURS.

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.

&&

TO REPORT SEVERE WEATHER...
CALL 1-800-856-0758.

LAT...LON 3403 8635 3355 8650 3355 8652 3340 8657
      3338 8669 3340 8688 3405 8671 3406 8667

$$
2 follow-up statements
139 
WGUS74 KBMX 201913
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
213 PM CDT TUE SEP 20 2011

ALC009-073-115-117-202100-
/O.CON.KBMX.FF.W.0062.000000T0000Z-110920T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BLOUNT AL-JEFFERSON AL-ST. CLAIR AL-SHELBY AL-
213 PM CDT TUE SEP 20 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTH CENTRAL SHELBY...
WEST CENTRAL ST. CLAIR...EASTERN JEFFERSON AND SOUTHERN BLOUNT
COUNTIES UNTIL 400 PM CDT...

AT 212 PM CDT...EMERGENCY MANAGEMENT REPORTED THAT FLASH FLOODING WAS
OCCURRING IN ALLGOOD IN BLOUNT COUNTY...WITH ADDITIONAL LOCALIZED 
FLOODING ACROSS PORTIONS JEFFERSON COUNTY.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
BIRMINGHAM...CLEVELAND...FULTONDALE...GARDENDALE...HOMEWOOD...
IRONDALE...LEEDS...MOODY...MOUNTAIN BROOK...ONEONTA...
PINSON-CLAY-CHALKVILLE...SPRINGVILLE...TRUSSVILLE...VESTAVIA HILLS...
ALLGOOD...ALTON...ARGO...B.J.C.C....BARBER MOTORSPORTS PARK...
BIRMINGHAM AIRPORT...BLUFF PARK...CAHABA HEIGHTS...CENTER POINT...
CLAY...COUNTY LINE...DALLAS...FAIRVIEW...FOWLER LAKE...GREYSTONE AND
KETONA LAKES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. RAINFALL FROM PERSISTENT RAINBANDS
WILL PRODUCE FLOODING IN LOW LYING AREAS AND ALONG STREETS. MANY
ROADS WILL BE CLOSED DUE TO HIGH WATER AND DRIVING IS NOT RECOMMENDED
DURING THE NEXT SEVERAL HOURS.

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.

&&

LAT...LON 3403 8635 3355 8650 3355 8652 3340 8657
      3338 8669 3340 8688 3405 8671 3406 8667

$$
873 
WGUS74 KBMX 202010
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
310 PM CDT TUE SEP 20 2011

ALC009-073-115-117-202100-
/O.CON.KBMX.FF.W.0062.000000T0000Z-110920T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BLOUNT AL-JEFFERSON AL-ST. CLAIR AL-SHELBY AL-
310 PM CDT TUE SEP 20 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTH CENTRAL SHELBY...
WEST CENTRAL ST. CLAIR...EASTERN JEFFERSON AND SOUTHERN BLOUNT
COUNTIES UNTIL 400 PM CDT...

SEVERAL REPORTS OF FLOODING HAVE BEEN NOTED ACROSS THE WARNED AREA. 
RAINFALL HAS BEEN ON THE DECREASING TREND OVER THE PAST 
HOUR...HOWEVER WATER MAY BE SLOW TO RECEDE IN SOME AREAS. CAUTION 
SHOULD BE USED IF FLOODING IS ENCOUNTERED.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
BIRMINGHAM...CLEVELAND...FULTONDALE...GARDENDALE...HOMEWOOD...
IRONDALE...LEEDS...MOODY...MOUNTAIN BROOK...ONEONTA...
PINSON-CLAY-CHALKVILLE...SPRINGVILLE...TRUSSVILLE...VESTAVIA HILLS...
ALLGOOD...ALTON...ARGO...B.J.C.C....BARBER MOTORSPORTS PARK...
BIRMINGHAM AIRPORT...BLUFF PARK...CAHABA HEIGHTS...CENTER POINT...
CLAY...COUNTY LINE...DALLAS...FAIRVIEW...FOWLER LAKE...GREYSTONE AND
KETONA LAKES.

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.

&&

LAT...LON 3403 8635 3355 8650 3355 8652 3340 8657
      3338 8669 3340 8688 3405 8671 3406 8667

$$

The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 9:07 PM CDTAreal Flood AdvisoryBMXTuscaloosa113 min
Sep 20, 9:47 AM CDTAreal Flood AdvisoryBMXBlount, Jefferson, St. Clair, Shelby, Talladega3 hr
Sep 20, 12:16 PM CDTAreal Flood AdvisoryBMXBlount, Etowah, Jefferson, St. Clair, Shelby3 hr
Sep 20, 1:31 PM CDTSpecial Weather StatementBMXAutauga44 min
Sep 20, 1:47 PM CDTAreal Flood AdvisoryBMXAutauga, Dallas, Lowndes3 hr
Sep 20, 2:01 PM CDTSevere Thunderstorm WarningBMXAutauga, Lowndes44 min
Sep 20, 2:28 PM CDTFlash Flood WarningBMXAutauga, Dallas, Lowndes3 hr
Sep 20, 2:53 PM CDTAreal Flood AdvisoryBMXBibb, Chilton, Dallas, Perry3 hr
Sep 20, 3:16 PM CDTAreal Flood AdvisoryBMXAutauga, Elmore, Lowndes, Montgomery3 hr
Sep 20, 3:26 PM CDTSpecial Weather StatementBMXElmore49 min
Sep 20, 3:46 PM CDTSpecial Weather StatementBMXBibb44 min
Sep 20, 3:58 PM CDTAreal Flood WarningBMXJefferson83 min
Sep 20, 4:02 PM CDTSpecial Weather StatementBMXDallas43 min
Sep 20, 5:33 PM CDTSpecial Weather StatementBMXTallapoosa42 min
Sep 20, 5:37 PM CDTSpecial Weather StatementBMXMacon53 min
Sep 20, 5:54 PM CDTSevere Thunderstorm WarningBMXElmore, Macon, Montgomery, Tallapoosa38 min

Nearby

Flash Flood Warnings in Alabama, 2011Every 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.