Alert archive / Alabama / Flash Flood Warnings in 2012

Flash Flood Warning 29, NWS Birmingham, AL

August 9, 2012Shelby County, Alabama

NWS Birmingham, AL issued this flash flood warning at Aug 9, 2012, 5:41 PM CDT for Shelby County, Alabama. It was in force for 3 hr. 6 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
Aug 9, 2012, 5:41 PM CDT (22:41 UTC)
Expired
Aug 9, 2012, 8:30 PM 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 22:42 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
Aug 9, 5:50 PM CDTHEAVY RAIN 05 Nne Alabaster, ALFIVE INCHES OF WATER REPORTED FLOWING ACROSS HWY 31 NEAR BOJANGLES.
Aug 9, 6:00 PM CDTFLASH FLOOD4 Ese Hoover, ALWATER COVERING THE ROADWAY ON HWY 119 NEAR THE INDIAN SPRINGS TOWN HALL. DEPTH OF WATER UNKNOWN AT THIS TIME.
Aug 9, 6:05 PM CDTFLASH FLOOD5 Ne Helena, ALWATER REPORTED FLOWING ACROSS STATE PARK ROAD APPROXIMATELY ONE MILE SOUTH OF HWY 119. DEPTH OF WATER UNKNOWN AT THIS TIME.
Aug 9, 6:10 PM CDTFLASH FLOOD3 E Hoover, ALREPORT OF ROADS FLOODED IN AND AROUND THE SOUTHLAKE AREA. PUBLIC WORKS IS ENROUTE.
Aug 9, 6:40 PM CDTFLASH FLOOD5 Nw Chelsea, ALWATER COVERING THE ROADWAY AT THE INTERSECTION OF HWY 119 AND OAK MOUNTAIN LAKE ROAD. DEPTH OF WATER IS UNKNOWN AT THIS TIME.
Aug 9, 6:45 PM CDTFLASH FLOOD4 Ese Hoover, ALFLASH FLOODING REPORTED ALONG HWY 119 AT JASMINE HILL RD AND ALSO AT CAHABA OAKS TRAIL. SOME TRAFFIC LANES WERE UNPASSABLE FOR A SHORT TIME AND THE POLICE DEPT HAD TO DIVERT TRAFFIC. WATER IS NOW BEGINNING TO RECEDE AND CONDITIONS ARE IMPROVING.

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, 10.7 hours before the alert went out and 18 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 2012-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1967 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 2012-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 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
1967 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
780 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

920 
WGUS54 KBMX 092241
FFWBMX
ALC117-100130-
/O.NEW.KBMX.FF.W.0029.120809T2241Z-120810T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
541 PM CDT THU AUG 9 2012

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

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

* UNTIL 830 PM CDT

* AT 541 PM CDT...NATIONAL WEATHER SERVICE INDICATED SLOW MOVING   
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
DOPPLER RADAR ESTIMATES SHOW UP TO TWO INCHES OF RAIN HAS FALLEN 
OVER THE WARNED AREA IN THE LAST HOUR...AND AN ADDITIONAL ONE TO TWO 
INCHES IS POSSIBLE WITHIN THE NEXT HOUR.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CHELSEA...PELHAM...HIGHLAND LAKES...INDIAN SPRINGS VILLAGE...
  MEADOWBROOK...OAK MOUNTAIN AMPITHEATER...OAK MOUNTAIN STATE PARK
  AND RIVERCHASE.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...
COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND
OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.

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 OR TWEET YOUR REPORT USING HASHTAG ALWX

LAT...LON 3327 8661 3325 8685 3333 8685 3334 8683
      3336 8682 3337 8678 3339 8678 3341 8675
      3343 8665

$$

19
1 follow-up statement
221 
WGUS74 KBMX 100005
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
705 PM CDT THU AUG 9 2012

ALC117-100130-
/O.CON.KBMX.FF.W.0029.000000T0000Z-120810T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SHELBY AL-
705 PM CDT THU AUG 9 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL SHELBY COUNTY
UNTIL 830 PM CDT...

AT 702 PM CDT...LOCAL LAW ENFORCEMENT AND EMERGENCY MANAGEMENT 
OFFICIALS REPORTED THAT FLASH FLOODING WAS OCCURRING IN THE PELHAM 
AND INDIAN SPRINGS VILLAGE AREAS. SEVERAL ROADWAYS ARE COVERED IN 
WATER...INCLUDING PORTIONS OF CAHABA VALLEY ROAD IN INDIAN SPRINGS 
VILLAGE AND HWY 31 IN PELHAM. FLOOD WATERS SHOULD SLOWLY RECEDE OVER 
THE NEXT COUPLE OF HOURS.

SOME LOCATIONS THAT WILL CONTINUE TO EXPERIENCE FLASH FLOODING 
INCLUDE...PELHAM...HIGHLAND LAKES...INDIAN SPRINGS VILLAGE...OAK 
MOUNTAIN AMPITHEATER...OAK MOUNTAIN STATE PARK AND RIVERCHASE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY ROADS
AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE ALSO SUBJECT TO FLOODING.

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 3327 8661 3325 8685 3333 8685 3334 8683
      3336 8682 3337 8678 3339 8678 3341 8675
      3343 8665

$$

19

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 7:45 PM CDTSpecial Weather StatementBMXWalker30 min
Aug 9, 9:29 AM CDTSpecial Weather StatementBMXTuscaloosa46 min
Aug 9, 10:17 AM CDTAreal Flood AdvisoryBMXFayette, Lamar, Pickens, Tuscaloosa3 hr
Aug 9, 10:26 AM CDTSpecial Weather StatementBMXJefferson49 min
Aug 9, 10:36 AM CDTSpecial Weather StatementBMXCherokee39 min
Aug 9, 11:07 AM CDTSpecial Weather StatementBMXJefferson38 min
Aug 9, 11:12 AM CDTSpecial Weather StatementBMXClay48 min
Aug 9, 11:21 AM CDTAreal Flood AdvisoryBMXBlount, Jefferson, St. Clair, Shelby114 min
Aug 9, 11:37 AM CDTSevere Thunderstorm WarningBMXCalhoun, St. Clair, Shelby, Talladega38 min
Aug 9, 11:46 AM CDTAreal Flood AdvisoryBMXEtowah119 min
Aug 9, 12:02 PM CDTSpecial Weather StatementBMXEtowah43 min
Aug 9, 12:15 PM CDTSpecial Weather StatementBMXCalhoun, Clay, Cleburne, Talladega45 min
Aug 9, 12:24 PM CDTAreal Flood AdvisoryBMXCalhoun, Clay, Talladega111 min
Aug 9, 1:49 PM CDTAreal Flood AdvisoryBMXMarengo, Sumter116 min
Aug 9, 3:43 PM CDTSpecial Weather StatementBMXDallas47 min
Aug 9, 4:33 PM CDTAreal Flood AdvisoryBMXElmore, Macon, Montgomery3 hr
Aug 9, 4:42 PM CDTAreal Flood AdvisoryBMXAutauga, Lowndes3 hr
Aug 9, 5:01 PM CDTSpecial Weather StatementBMXLee44 min
Aug 9, 5:13 PM CDTAreal Flood AdvisoryBMXLee2 hr
Aug 9, 5:21 PM CDTAreal Flood AdvisoryBMXShelby114 min
Aug 9, 6:39 PM CDTSpecial Weather StatementBMXTalladega51 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.