Alert archive / Alabama / Flash Flood Warnings in 2011

Flash Flood Warning 35, NWS Mobile, AL

September 22, 2011Choctaw County, Alabama

NWS Mobile, AL issued this flash flood warning at Sep 22, 2011, 4:58 PM CDT for Choctaw County, Alabama. It was in force for 3 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 22, 2011, 4:58 PM CDT (21:58 UTC)
Expired
Sep 22, 2011, 8:00 PM CDT
In force
3 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

County Choctaw County, AL

The radar

The Mobile radar (KMOB), 120 km from the middle of the area, began a volume at 21:59 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

Jackson, MS (KJAN), launched 12:00Z, 10.0 hours before the alert went out and 169 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, Jackson, MS at 12:00Z on 2011-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1142 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, Jackson, MS at 12:00Z on 2011-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
1142 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
822 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

299 
WGUS54 KMOB 222158
FFWMOB
ALC023-230100-
/O.NEW.KMOB.FF.W.0035.110922T2158Z-110923T0100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN CHOCTAW COUNTY IN SOUTHWEST ALABAMA...

* UNTIL 800 PM CDT

* AT 455 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED VERY HEAVY
  RAIN FROM A SERIES OF THUNDERSTORMS MOVING NORTHEASTWARD ACROSS
  SOUTHWESTERN CHOCTAW COUNTY.  DOPPLER RADAR RAINFALL ESTIMATES
  INDICATE THAT UP TO 3 TO 4 INCHES OF RAIN HAS FALLEN IN THE PAST
  HOUR OVER THIS AREA AND ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2
  INCHES ARE EXPECTED OVER THE NEXT HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO AQUILLA AND
  CONTWELL

TO REPORT FLASH FLOODING TO YOUR NATIONAL WEATHER SERVICE...CALL TOLL
FREE AT 1 8 7 7 6 3 3 6 7 7 2.

LAT...LON 3178 8835 3170 8838 3170 8843 3170 8846
      3171 8847 3176 8847 3183 8841

$$
1 follow-up statement
237 
WGUS74 KMOB 222320
FFSMOB

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
620 PM CDT THU SEP 22 2011

ALC023-230100-
/O.CON.KMOB.FF.W.0035.000000T0000Z-110923T0100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHOCTAW AL-
620 PM CDT THU SEP 22 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR
SOUTHWESTERN CHOCTAW COUNTY...

AT 610 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT MOST OF THE HEAVY RAINS HAVE ENDED OVER THE AREA ALTHOUGH LIGHT 
RAIN CONTINUES.  DOPPLER RADAR RAINFALL ESTIMATES INDICATE THAT 
AROUND FOUR INCHES OF RAIN HAS FALLEN OVER THE AREA OVER THE PAST 
TWO HOURS.  ALTHOUGH THE HEAVY RAINS HAVE ENDED...THE FLASH FLOOD 
WARNING REMAINS IN EFFECT TO ALLOW FOR THE EXCESSIVE RAIN TO 
COMPLETELY RUN OFF.

LAT...LON 3178 8835 3170 8838 3170 8843 3170 8846
      3171 8847 3176 8847 3183 8841

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 21, 9:10 PM CDTAreal Flood AdvisoryMOBButler, Conecuh, Crenshaw, Monroe2 hr
Sep 22, 10:17 AM CDTSpecial Marine WarningMOB43 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.