Alert archive / Alabama / Flash Flood Warnings in 2012

Flash Flood Warning 22, NWS Birmingham, AL

July 31, 2012Shelby County, Alabama

NWS Birmingham, AL issued this flash flood warning at Jul 31, 2012, 2:10 AM CDT for Shelby County, Alabama. It was in force for 3 hr. 7 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
Jul 31, 2012, 2:10 AM CDT (07:10 UTC)
Expired
Jul 31, 2012, 5:00 AM CDT
In force
3 hr
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Flood severity
None

County Shelby County, AL

The radar

The Birmingham radar (KBMX), 19 km from the middle of the area, began a volume at 07:09 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
Jul 31, 2:20 AM CDTFLASH FLOODPelham, ALSEVERAL HOMES TAKING ON WATER.
Jul 31, 2:45 AM CDTFLASH FLOOD4 Ne Helena, ALMULTIPLE HOMES FLOODED IN THE SADDLE RUN SUBDIVISION.
Jul 31, 2:45 AM CDTFLASH FLOOD4 Ne Helena, ALMULTIPLE HOMES FLOODED IN THE STRATFORD PLACE SUBDIVISION.
Jul 31, 2:50 AM CDTFLASH FLOOD1 N Alabaster, ALPORTION OF HWY 31 CLOSED NEAR SHELBY BAPTIST MEDICAL CENTER WITH OVER ONE FOOT OF WATER COVERING THE ROADWAY.
Jul 31, 2:50 AM CDTFLASH FLOOD3 Nne Alabaster, ALEVACUATIONS REPORTEDLY TAKING PLACE AT BIRMINGHAM SOUTH CAMPGROUND DUE TO FLOODING. ENTIRE BACK SIDE OF CAMPGROUND IS FLOODED.
Jul 31, 3:00 AM CDTFLASH FLOOD4 N Alabaster, ALFLOODING REPORTED AT THE BELLE VISTA MOBILE HOME PARK.
Jul 31, 3:00 AM CDTFLASH FLOOD5 N Alabaster, ALFLOODING REPORTED AT THE PELHAM YMCA.

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, 7.2 hours before the alert went out and 19 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 2012-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 771 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 00:00Z on 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
771 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1852 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

171 
WGUS54 KBMX 310710
FFWBMX
ALC117-311000-
/O.NEW.KBMX.FF.W.0022.120731T0710Z-120731T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
210 AM CDT TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SHELBY COUNTY IN ALABAMA...

* UNTIL 500 AM CDT

* AT 208 AM CDT...NATIONAL WEATHER SERVICE INDICATED SLOW MOVING
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.
  RADAR ESTIMATES OF 2 TO 3 INCHES HAVE OCCURRED ACROSS NORTHERN
  SHELBY COUNTY SINCE 1 AM CDT...AND THE HEAVIER RAINFALL WILL SPREAD
  ACROSS THE REMAINDER OF THE COUNTY BY 3 AM CDT.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ALABASTER...CALERA...CHELSEA...COLUMBIANA...HELENA...MONTEVALLO...
  PELHAM...WILSONVILLE...AMERICAN VILLAGE...FOWLER LAKE...
  GREYSTONE...HARPERSVILLE...HIGHLAND LAKES...INDIAN SPRINGS
  VILLAGE...LAKE PURDY...MAYLENE...MEADOWBROOK...MOUNT LAUREL...OAK
  MOUNTAIN AMPITHEATER...OAK MOUNTAIN STATE PARK...RIVERCHASE...
  SHELBY COUNTY AIRPORT...UNIVERSITY OF MONTEVALLO...VANDIVER...
  VINCENT...WESTOVER AND WILTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

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

LAT...LON 3350 8648 3350 8638 3338 8638 3335 8634
      3329 8636 3328 8643 3318 8650 3312 8646
      3302 8652 3307 8661 3305 8690 3310 8697
      3316 8697 3317 8703 3325 8703 3333 8683
      3347 8667 3347 8661 3354 8651

$$
1 follow-up statement
218 
WGUS74 KBMX 310859
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
359 AM CDT TUE JUL 31 2012

ALC117-311000-
/O.CON.KBMX.FF.W.0022.000000T0000Z-120731T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SHELBY AL-
359 AM CDT TUE JUL 31 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SHELBY COUNTY UNTIL 500
AM CDT...

AT 353 AM CDT...DOPPLER RADAR INDICATES LIGHT TO MODERATE RAINFALL 
CONTINUING ACROSS THE WARNED AREA. POLICE IN PELHAM AND ALABASTER 
HAVE REPORTED FLOODING IN SOME HOMES AND BUSINESSES. ANOTHER CLUSTER 
OF THUNDERSTORMS WITH HEAVY RAINFALL COULD AFFECT SHELBY COUNTY BY 
500 AM CDT...AND THE WARNING MAY NEED TO BE EXTENDED IN TIME.


RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
ALABASTER...CALERA...CHELSEA...COLUMBIANA...HELENA...MONTEVALLO...
PELHAM...WILSONVILLE...AMERICAN VILLAGE...FOWLER LAKE...GREYSTONE...
HARPERSVILLE...HIGHLAND LAKES...INDIAN SPRINGS VILLAGE...LAKE
PURDY...MAYLENE...MEADOWBROOK...MOUNT LAUREL...OAK MOUNTAIN
AMPITHEATER...OAK MOUNTAIN STATE PARK...RIVERCHASE...SHELBY COUNTY
AIRPORT...UNIVERSITY OF MONTEVALLO...VANDIVER...VINCENT...WESTOVER
AND WILTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3350 8648 3350 8638 3338 8638 3335 8634
      3329 8636 3328 8643 3318 8650 3312 8646
      3302 8652 3307 8661 3305 8690 3310 8697
      3316 8697 3317 8703 3325 8703 3333 8683
      3347 8667 3347 8661 3354 8651

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 7:18 PM CDTSevere Thunderstorm WarningBMXPike27 min
Jul 30, 7:25 PM CDTAreal Flood AdvisoryBMXPike3 hr
Jul 30, 8:13 PM CDTFlash Flood WarningBMXPike3 hr
Jul 30, 11:57 PM CDTSevere Thunderstorm WarningBMXMarion78 min
Jul 31, 12:15 AM CDTSpecial Weather StatementBMXWalker, Winston45 min
Jul 31, 12:27 AM CDTSpecial Weather StatementBMXSt. Clair48 min
Jul 31, 12:32 AM CDTSevere Thunderstorm WarningBMXBlount43 min
Jul 31, 12:34 AM CDTSevere Thunderstorm WarningBMXWinston56 min
Jul 31, 12:48 AM CDTSevere Thunderstorm WarningBMXJefferson, St. Clair57 min
Jul 31, 12:57 AM CDTSevere Thunderstorm WarningBMXJefferson, Walker48 min
Jul 31, 1:01 AM CDTSevere Thunderstorm WarningBMXFayette, Walker74 min
Jul 31, 1:24 AM CDTAreal Flood AdvisoryBMXWinston2 hr
Jul 31, 1:36 AM CDTAreal Flood AdvisoryBMXJefferson, St. Clair, Shelby, Walker3 hr
Jul 31, 1:40 AM CDTSevere Thunderstorm WarningBMXJefferson, Shelby, Talladega65 min
Jul 31, 1:53 AM CDTFlash Flood WarningBMXJefferson3 hr
Jul 31, 2:20 AM CDTSevere Thunderstorm WarningBMXBibb, Chilton, Coosa70 min
Jul 31, 2:40 AM CDTSpecial Weather StatementBMXMarion, Winston65 min
Jul 31, 3:01 AM CDTSevere Thunderstorm WarningBMXAutauga74 min
Jul 31, 3:06 AM CDTSpecial Weather StatementBMXWinston24 min
Jul 31, 3:14 AM CDTSevere Thunderstorm WarningBMXElmore44 min
Jul 31, 3:20 AM CDTSevere Thunderstorm WarningBMXMarion, Walker, Winston55 min
Jul 31, 3:37 AM CDTSpecial Weather StatementBMXLowndes, Montgomery53 min
Jul 31, 4:09 AM CDTSevere Thunderstorm WarningBMXJefferson, Shelby, Walker71 min
Jul 31, 4:38 AM CDTFlash Flood WarningBMXJefferson, Shelby3 hr
Jul 31, 4:40 AM CDTSevere Thunderstorm WarningBMXChilton, Jefferson, Shelby, Walker39 min
Jul 31, 6:11 AM CDTSpecial Weather StatementBMXDallas, Hale, Perry49 min
Jul 31, 6:36 AM CDTSpecial Weather StatementBMXBlount, Etowah, St. Clair39 min
Jul 31, 7:28 AM CDTFlash Flood WarningBMXJefferson, Shelby3 hr
Jul 31, 8:32 AM CDTFlash Flood WarningBMXLowndes2 hr
Jul 31, 8:44 AM CDTSevere Thunderstorm WarningBMXJefferson, St. Clair, Shelby, Talladega, Walker46 min
Jul 31, 9:08 AM CDTSevere Thunderstorm WarningBMXChilton, Coosa, Shelby, Talladega26 min
Jul 31, 10:30 AM CDTAreal Flood WarningBMXJefferson, Shelby6 hr

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.