Alert archive / Alabama / Flash Flood Warnings in 2012

Flash Flood Warning 6, NWS Birmingham, AL

March 23, 2012St. Clair County, Alabama

NWS Birmingham, AL issued this flash flood warning at Mar 23, 2012, 11:27 AM CDT for St. Clair County, Alabama. It was in force for 3 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
Mar 23, 2012, 11:27 AM CDT (16:27 UTC)
Expired
Mar 23, 2012, 2:30 PM CDT
In force
3 hr
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Flood severity
None

County St. Clair County, AL

The radar

The Birmingham radar (KBMX), 74 km from the middle of the area, began a volume at 16:29 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
Mar 23, 12:15 PM CDTFLASH FLOODRagland, ALSEVERAL HOURS OF RAINFALL...RESULTED IN 2 TO 4 INCHES FALLING ACROSS THE NORTHEASTERN PORTIONS OF ST CLAIR CLAIR COUNTY. SEVERAL ROADS ARE FLOODED ACROSS THIS AREA.

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, 4.5 hours before the alert went out and 74 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 2012-03-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 490 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2012-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 176 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
490 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
500 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
176 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.1

Open this sounding in Storm Lab

The text

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

576 
WGUS54 KBMX 231627
FFWBMX
ALC115-231930-
/O.NEW.KBMX.FF.W.0006.120323T1627Z-120323T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1127 AM CDT FRI MAR 23 2012

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN ST. CLAIR COUNTY IN ALABAMA...

* UNTIL 230 PM CDT

* AT 1124 AM CDT...NATIONAL WEATHER SERVICE INDICATED SLOW MOVING    
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  RAIN FALL OF 1 TO 2 INCHES OVER THE PAST HOUR HAS FALLEN IN THE    
  WARNED AREA WITH ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING   
  TO THE SOUTHWEST OF THE AREA. THESE SHOWERS AND THUNDERSTORMS WILL 
  MOVE BACK OVER THE WARNED AREA OVER THE NEXT HOUR. AN ADDITIONAL 1 
  INCH IS POSSIBLE WITH THESE STORMS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...BALD
  ROCK AND RAGLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 INCH IS POSSIBLE...DO NOT DRIVE 
INTO FLOODED AREAS.

&&

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

LAT...LON 3378 8605 3371 8612 3371 8614 3369 8614
      3367 8617 3370 8619 3369 8621 3367 8619
      3350 8647 3351 8648 3355 8648 3356 8654
      3385 8610

$$
1 follow-up statement
960 
WGUS74 KBMX 231754
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1254 PM CDT FRI MAR 23 2012

ALC115-231930-
/O.CON.KBMX.FF.W.0006.000000T0000Z-120323T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ST. CLAIR AL-
1254 PM CDT FRI MAR 23 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN ST. CLAIR
COUNTY UNTIL 230 PM CDT...

AT 1252 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR 
INDICATES THAT 2 TO 4 INCHES HAS FALLEN OVER THE WARNED AREA IN THE 
PAST 2 HOURS. RAINFALL IS BEGINNING TO DIMINISH AND MOVE OUT OF THE 
AREA. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
BALD ROCK AND RAGLAND.

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 3378 8605 3371 8612 3371 8614 3369 8614
      3367 8617 3370 8619 3369 8621 3367 8619
      3350 8647 3351 8648 3355 8648 3356 8654
      3385 8610

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 22, 7:03 PM CDTAreal Flood AdvisoryBMXMarengo3 hr
Mar 22, 8:31 PM CDTAreal Flood WarningBMXMarengo3 hr
Mar 22, 10:44 PM CDTAreal Flood AdvisoryBMXDallas, Perry2 hr
Mar 23, 3:18 AM CDTSpecial Weather StatementBMXAutauga27 min
Mar 23, 6:16 AM CDTAreal Flood AdvisoryBMXAutauga, Dallas, Lowndes3 hr
Mar 23, 6:24 AM CDTFlash Flood WarningBMXSumter3 hr
Mar 23, 6:39 AM CDTAreal Flood AdvisoryBMXGreene, Pickens3 hr
Mar 23, 7:46 AM CDTSpecial Weather StatementBMXTuscaloosa44 min
Mar 23, 8:20 AM CDTSpecial Weather StatementBMXMontgomery, Pike40 min
Mar 23, 8:54 AM CDTAreal Flood WarningBMXLowndes3 hr
Mar 23, 8:59 AM CDTTornado WarningBMXPike31 min
Mar 23, 9:28 AM CDTAreal Flood WarningBMXSumter3 hr
Mar 23, 9:29 AM CDTTornado WarningBMXPike31 min
Mar 23, 10:04 AM CDTTornado WarningBMXPike26 min
Mar 23, 10:17 AM CDTSpecial Weather StatementBMXBarbour, Bullock43 min
Mar 23, 10:30 AM CDTSpecial Weather StatementBMXPike30 min
Mar 23, 10:35 AM CDTSpecial Weather StatementBMXSt. Clair25 min
Mar 23, 10:53 AM CDTFlash Flood WarningBMXPike3 hr
Mar 23, 10:55 AM CDTAreal Flood AdvisoryBMXJefferson, St. Clair, Shelby2 hr
Mar 23, 10:56 AM CDTSpecial Weather StatementBMXBarbour64 min
Mar 23, 11:01 AM CDTSpecial Weather StatementBMXSt. Clair59 min
Mar 23, 11:52 AM CDTAreal Flood AdvisoryBMXCalhoun, Etowah3 hr
Mar 23, 12:22 PM CDTAreal Flood AdvisoryBMXBarbour, Bullock3 hr
Mar 23, 1:36 PM CDTAreal Flood AdvisoryBMXCalhoun, Cherokee3 hr
Mar 23, 4:02 PM CDTSevere Thunderstorm WarningBMXElmore28 min
Mar 23, 4:28 PM CDTSpecial Weather StatementBMXElmore47 min
Mar 23, 5:13 PM CDTSpecial Weather StatementBMXTallapoosa47 min

Nearby

Flash Flood Warnings in Alabama, 2012Every flash flood warning in 2012

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.