Alert archive / Alabama / Flash Flood Warnings in 2009

Flash Flood Warning 53, NWS Mobile, AL

September 21, 2009Mobile County, Alabama

NWS Mobile, AL issued this flash flood warning at Sep 21, 2009, 10:11 AM CDT for Mobile County, Alabama. It was in force for 87 min. 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 21, 2009, 10:11 AM CDT (15:11 UTC)
Expired: Sep 21, 2009, 11:38 AM CDT
In force: 87 min
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

County Mobile County, AL

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 3.2 hours before the alert went out and 150 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2636 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 482 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KMOB 211511
FFWMOB
ALC097-211715-
/O.NEW.KMOB.FF.W.0053.090921T1511Z-090921T1715Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOBILE AL
1011 AM CDT MON SEP 21 2009

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL MOBILE COUNTY IN SOUTHWEST ALABAMA...

* UNTIL 1215 PM CDT

* AT 1008 AM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED VERY
  HEAVY RAIN FROM SLOW MOVING THUNDERSTORM OVER THE WARNED AREA.
  AS MUCH AS 3 TO 4 INCHES HAS FALLEN NEAR THE INTERSTATE 65 CORRIDOR
  SOUTH OF SARALAND AND NEAR PRICHARD OVER THE PAST HOUR. ADDITIONAL
  THUNDERSTORMS ARE DEVELOPING TO THE SOUTH WHICH MAY AFFECT THESE
  LOCATIONS AS WELL AS PRODUCE FLOODING CONCERNS ACROSS SOUTH CENTRAL
  MOBILE COUNTY. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WHISTLER...
  SARALAND...PRICHARD...MAGNOLIA GROVE GOLF COURSE...KUSHLA...I65 AND
  US 45...I65 AND I165...I65 AND AL 158...FOREST HILL...EIGHT MILE
  AND CHICKASAW

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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 3047 8832 3086 8816 3083 8801 3043 8816

$$

JFB

1 follow-up statement

000 
WGUS74 KMOB 211638
FFSMOB

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
1138 AM CDT MON SEP 21 2009

ALC097-211647-
/O.CAN.KMOB.FF.W.0053.000000T0000Z-090921T1715Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOBILE AL-
1138 AM CDT MON SEP 21 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL MOBILE
COUNTY...

THE HEAVY RAIN ACROSS THE WARNING AREA HAS ENDED...THEREFORE THE 
FLASH FLOOD WARNING HAS BEEN CANCELLED. 

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

LAT...LON 3047 8832 3086 8816 3083 8801 3043 8816

$$

JFB

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 21, 4:25 AM CDT	Flash Flood Watch	MOB	Choctaw, Clarke, Monroe, Washington, Wilcox	39 hr
Sep 21, 9:48 AM CDT	Areal Flood Advisory	MOB	Mobile	117 min
Sep 21, 10:37 AM CDT	Areal Flood Advisory	MOB	Clarke, Monroe, Wilcox	3 hr
Sep 21, 11:02 AM CDT	River Flood Warning	MOB	Choctaw, Clarke, Washington	10 days
Sep 21, 11:02 AM CDT	River Flood Warning	MOB	Choctaw, Clarke, Washington	11 days
Sep 21, 11:23 AM CDT	Marine Weather Statement	MOB		4 hr
Sep 21, 4:49 PM CDT	Flash Flood Warning	MOB	Covington	116 min

Nearby

Flash Flood Warnings in Alabama, 2009 Every flash flood warning in 2009

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.