Alert archive / Alabama / Flash Flood Warnings in 2011

Flash Flood Warning 66, NWS Birmingham, AL

September 22, 2011Jefferson County, St. Clair County, Shelby County, Alabama

NWS Birmingham, AL issued this flash flood warning at Sep 22, 2011, 9:39 PM CDT for Jefferson County, St. Clair County, Shelby County, Alabama. It was in force for 3 hr. 2 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 22, 2011, 9:39 PM CDT (02:39 UTC)
Expired
Sep 23, 2011, 12:30 AM CDT
In force
3 hr
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Flood severity
None

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

The radar

The Birmingham radar (KBMX), 48 km from the middle of the area, began a volume at 02:40 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 22, 10:10 PM CDTFLASH FLOODVandiver, ALPUBLIC REPORT OF FLOWING WATER UP TO 2 FEET DEEP IN VANDIVER AREA NEAR COUNTY ROAD 43.
Sep 23, 12:15 AM CDTHEAVY RAIN 6Leeds, ALRAIN AMOUNTS OF 6 INCHES WERE REPORTED NEAR LEEDS. A LANDSLIDE OCCURRED DUE TO THE HEAVY RAIN NEAR DUNNAVANT ROAD. SEVERAL LARGE ROCKS BLOCKED THE ROADWAY.

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 00:00Z, 2.7 hours before the alert went out and 48 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 00:00Z on 2011-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2177 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2011-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.19395878Sfc1 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
2177 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
858 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
51 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.

739 
WGUS54 KBMX 230239
FFWBMX
ALC073-115-117-230530-
/O.NEW.KBMX.FF.W.0066.110923T0239Z-110923T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
939 PM CDT THU SEP 22 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL JEFFERSON COUNTY IN ALABAMA...
  NORTHEASTERN SHELBY COUNTY IN ALABAMA...
  SOUTHWESTERN ST. CLAIR COUNTY IN ALABAMA...

* UNTIL 1230 AM CDT

* AT 938 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...
  IRONDALE...LEEDS...MOODY...ALTON...BALD ROCK...BARBER MOTORSPORTS
  PARK...BRANCHVILLE...GREYSTONE...LAKE PURDY...MEADOWBROOK AND
  VANDIVER.

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.

&&

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

LAT...LON 3368 8642 3347 8638 3340 8670 3357 8675

$$
1 follow-up statement
744 
WGUS74 KBMX 230322
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1022 PM CDT THU SEP 22 2011

ALC073-115-117-230530-
/O.CON.KBMX.FF.W.0066.000000T0000Z-110923T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JEFFERSON AL-ST. CLAIR AL-SHELBY AL-
1022 PM CDT THU SEP 22 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHEASTERN SHELBY...
SOUTHWESTERN ST. CLAIR AND EAST CENTRAL JEFFERSON COUNTIES UNTIL 1230
AM CDT...

AT 1018 PM CDT...THE PUBLIC REPORTED THAT FLASH FLOODING WAS 
OCCURRING IN THE VANDIVER AREA AND LEEDS AREAS. SEVERAL ROADS IN 
THESE AREAS HAVE BEEN REPORTED COVERED WITH WATER WITH SOME VEHICLES 
FLOODED OUT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. RAINFALL FROM PERSISTENT RAINBANDS
HAS PRODUCED 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 3368 8642 3347 8638 3340 8670 3357 8675

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 22, 8:51 PM CDTAreal Flood AdvisoryBMXJefferson, St. Clair, Shelby, Talladega114 min
Sep 23, 12:30 AM CDTAreal Flood AdvisoryBMXJefferson, St. Clair, Shelby, Talladega2 hr
Sep 23, 2:06 AM CDTAreal Flood AdvisoryBMXTalladega3 hr
Sep 23, 2:15 AM CDTSpecial Weather StatementBMXTalladega30 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.