Alert archive / Alabama / Flash Flood Warnings in 2012

Flash Flood Warning 38, NWS Mobile, AL

September 4, 20125 counties in Alabama; Escambia County, Santa Rosa County, Florida

NWS Mobile, AL issued this flash flood warning at Sep 4, 2012, 3:34 PM CDT for 5 counties in Alabama; Escambia County, Santa Rosa County, Florida. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 4, 2012, 3:34 PM CDT (20:34 UTC)
Expired
Sep 4, 2012, 9:30 PM CDT
In force
6 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

Counties Baldwin County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Monroe County, AL, Escambia County, FL, Santa Rosa County, FL

The radar

The Mobile radar (KMOB), 85 km from the middle of the area, began a volume at 20:37 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.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 8.6 hours before the alert went out and 231 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, Slidell Radar S, LA at 12:00Z on 2012-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1547 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, Slidell Radar S, LA at 12:00Z on 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 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
1547 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
675 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
-0.2
Supercell composite
-1.5

Open this sounding in Storm Lab

The text

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

970 
WGUS54 KMOB 042034
FFWMOB
ALC003-025-035-053-099-FLC033-113-050230-
/O.NEW.KMOB.FF.W.0038.120904T2034Z-120905T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOBILE AL
334 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN ESCAMBIA COUNTY IN NORTHWEST FLORIDA...
  NORTHWESTERN SANTA ROSA COUNTY IN NORTHWEST FLORIDA...
  SOUTHWESTERN CONECUH COUNTY IN SOUTH CENTRAL ALABAMA...
  WESTERN ESCAMBIA COUNTY IN SOUTH CENTRAL ALABAMA...
  SOUTHWESTERN MONROE COUNTY IN SOUTH CENTRAL ALABAMA...
  NORTH CENTRAL BALDWIN COUNTY IN SOUTHWEST ALABAMA...
  SOUTHEASTERN CLARKE COUNTY IN SOUTHWEST ALABAMA...

* UNTIL 930 PM CDT

* AT 327 PM CDT...VERY HEAVY RAINFALL WAS INDICATED OVER THE
  WARNED AREA AND RADAR ESTIMATES SHOW 1.5 TO 2.5 INCHES OF RAINFALL
  HAS OCCURRED OVER THE PAST HOUR. AN ADDITIONAL 1 TO 2 INCHES IS
  POSSIBLE BEFORE MID EVENING. THIS WILL LIKELY CAUSE FLASH
  FLOODING IN THE WARNED AREA.

* LOCATIONS IMPACTED INCLUDE...
  POARCH CREEK RESERVATION...                 FLOMATON...
  CENTURY...            I65 AND CR 47...      I65 AND AL 287...
  URIAH...              MEGARGEL...           I65 AND CR 6...
  I65 AND AL 41...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR OCCURRING. SEEK
HIGHER GROUND IMMEDIATELY. DO NOT DRIVE OR WALK INTO AREAS WHERE
WATER CROSSES A ROAD. TURN AROUND - DON'T DROWN!

&&

LAT...LON 3081 8760 3091 8776 3109 8785 3123 8788
      3142 8776 3148 8759 3131 8726 3142 8712
      3110 8708 3092 8717 3080 8736

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 6:52 AM CDTAreal Flood AdvisoryMOBButler, Crenshaw3 hr
Sep 4, 7:20 AM CDTAreal Flood AdvisoryMOBCovington3 hr
Sep 4, 7:30 AM CDTFlash Flood WarningMOBButler, Crenshaw6 hr
Sep 4, 8:12 AM CDTFlash Flood WatchMOBButler, Clarke, Conecuh, Covington, Crenshaw, Escambia and 2 more25 hr
Sep 4, 8:26 AM CDTFlash Flood WarningMOBButler, Covington, Crenshaw6 hr
Sep 4, 9:10 AM CDTFlash Flood WarningMOBWilcox6 hr
Sep 4, 10:13 AM CDTAreal Flood AdvisoryMOBClarke, Conecuh, Monroe3 hr
Sep 4, 11:40 AM CDTFlash Flood WarningMOBButler, Conecuh, Monroe3 hr
Sep 4, 1:33 PM CDTAreal Flood WarningMOBButler, Crenshaw3 hr
Sep 4, 2:14 PM CDTAreal Flood WarningMOBButler, Conecuh, Covington, Crenshaw, Monroe, Wilcox2 hr
Sep 4, 3:44 PM CDTSevere Thunderstorm WarningMOBBaldwin, Escambia61 min
Sep 4, 4:26 PM CDTAreal Flood WarningMOBConecuh, Monroe8 hr
Sep 4, 4:44 PM CDTSevere Thunderstorm WarningMOBBaldwin61 min
Sep 4, 4:59 PM CDTSevere Thunderstorm WarningMOBBaldwin, Escambia61 min
Sep 4, 5:51 PM CDTSevere Thunderstorm WarningMOBBaldwin54 min
Sep 4, 5:56 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Monroe, Washington, Wilcox64 min
Sep 4, 6:37 PM CDTSevere Thunderstorm WarningMOBBaldwin30 min
Sep 4, 6:49 PM CDTSevere Thunderstorm WarningMOBBaldwin, Choctaw, Clarke, Escambia, Mobile, Monroe and 2 more34 min
Sep 4, 10:44 AM CDTAreal Flood AdvisoryMOBOkaloosa2 hr

Nearby

Flash Flood Warnings in Alabama, 2012Flash Flood Warnings in Florida, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.