Alert archive / Alabama / Tornado Warnings in 2011

Tornado Warning 114, NWS Mobile, AL

September 4, 2011Clarke County, Washington County, Alabama

NWS Mobile, AL issued this tornado warning at Sep 4, 2011, 1:20 PM CDT for Clarke County, Washington County, Alabama. It was in force for 55 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 4, 2011, 1:20 PM CDT (18:20 UTC)
Expired
Sep 4, 2011, 2:15 PM CDT
In force
55 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon

Counties Clarke County, AL, Washington County, AL

The radar

The Mobile radar (KMOB), 68 km from the middle of the area, began a volume at 18:21 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 4, 5:05 AM CDTTornado WatchSPC11 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.3 hours before the alert went out and 200 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 2011-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2528 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 2011-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 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
2528 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
473 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
3.0
Supercell composite
18.9

Open this sounding in Storm Lab

The text

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

079 
WFUS54 KMOB 041820
TORMOB
ALC025-129-041915-
/O.NEW.KMOB.TO.W.0114.110904T1820Z-110904T1915Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOBILE AL
120 PM CDT SUN SEP 4 2011

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL CLARKE COUNTY IN SOUTHWEST ALABAMA...
  SOUTHEASTERN WASHINGTON COUNTY IN SOUTHWEST ALABAMA...

* UNTIL 215 PM CDT

* AT 116 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 18 MILES EAST OF
  CITRONELLE...OR 3 MILES EAST OF CALVERT...MOVING NORTH AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WAGARVILLE...         MCINTOSH...           MALCOLM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF IN MANUFACTURED HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 400 PM CDT SUNDAY AFTERNOON
FOR SOUTHWESTERN ALABAMA AND NORTHWEST FLORIDA AND SOUTHEAST
MISSISSIPPI.

&&

LAT...LON 3146 8783 3115 8791 3115 8792 3116 8793
      3115 8794 3115 8796 3117 8799 3115 8802
      3115 8803 3148 8811
TIME...MOT...LOC 1819Z 186DEG 25KT 3117 8796

$$
1 follow-up statement
191 
WWUS54 KMOB 041913
SVSMOB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
213 PM CDT SUN SEP 4 2011

ALC025-129-041923-
/O.EXP.KMOB.TO.W.0114.000000T0000Z-110904T1915Z/
WASHINGTON AL-CLARKE AL-
213 PM CDT SUN SEP 4 2011

...THE TORNADO WARNING FOR SOUTH CENTRAL CLARKE AND SOUTHEASTERN
WASHINGTON COUNTIES WILL EXPIRE AT 215 PM CDT...

THE STORM THAT PROMPTED THE WARNING HAS WEAKENED AND NO LONGER SHOWS 
SIGNS OF TORNADIC DEVELOPMENT.  THEREFORE...THE WARNING WILL BE 
ALLOWED TO EXPIRE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 400 PM CDT SUNDAY AFTERNOON
FOR SOUTHWESTERN ALABAMA AND NORTHWEST FLORIDA AND SOUTHEAST
MISSISSIPPI.

LAT...LON 3146 8783 3115 8791 3115 8792 3116 8793
      3115 8794 3115 8796 3117 8799 3115 8802
      3115 8803 3148 8811
TIME...MOT...LOC 1913Z 186DEG 25KT 3154 8791

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 7:53 PM CDTAreal Flood WarningMOBBaldwin, Mobile6 hr
Sep 3, 8:02 PM CDTSpecial Marine WarningMOB43 min
Sep 3, 8:24 PM CDTSpecial Marine WarningMOB51 min
Sep 3, 9:11 PM CDTRiver Flood WarningMOBCovington, Escambia12 hr
Sep 3, 10:34 PM CDTSpecial Marine WarningMOB41 min
Sep 3, 11:11 PM CDTTornado WarningMOBMobile64 min
Sep 3, 11:58 PM CDTTornado WarningMOBMobile62 min
Sep 4, 12:13 AM CDTSpecial Marine WarningMOB2 hr
Sep 4, 12:59 AM CDTTornado WarningMOBMobile61 min
Sep 4, 1:14 AM CDTFlash Flood WarningMOBMobile3 hr
Sep 4, 1:40 AM CDTFlash Flood WarningMOBMobile3 hr
Sep 4, 1:59 AM CDTTornado WarningMOBMobile45 min
Sep 4, 2:16 AM CDTSpecial Marine WarningMOB119 min
Sep 4, 2:46 AM CDTTornado WarningMOBBaldwin59 min
Sep 4, 3:16 AM CDTSpecial Marine WarningMOB119 min
Sep 4, 3:57 AM CDTTornado WarningMOBBaldwin42 min
Sep 4, 4:49 AM CDTSpecial Marine WarningMOB86 min
Sep 4, 5:36 AM CDTFlash Flood WarningMOBCovington, Escambia3 hr
Sep 4, 5:51 AM CDTSpecial Marine WarningMOB114 min
Sep 4, 9:42 AM CDTSpecial Marine WarningMOB33 min
Sep 4, 9:59 AM CDTRiver Flood WarningMOBChoctaw, Clarke, Washington4 days
Sep 4, 9:59 AM CDTRiver Flood WarningMOBChoctaw, Clarke, Washington5 days
Sep 4, 10:43 AM CDTSpecial Marine WarningMOB47 min
Sep 4, 10:44 AM CDTSpecial Marine WarningMOB46 min
Sep 4, 11:29 AM CDTSpecial Marine WarningMOB46 min
Sep 4, 11:46 AM CDTTornado WarningMOBBaldwin, Mobile19 min
Sep 4, 12:12 PM CDTTornado WarningMOBWashington63 min
Sep 4, 12:58 PM CDTTornado WarningMOBWashington62 min
Sep 4, 4:01 PM CDTTornado WarningMOBChoctaw, Clarke59 min
Sep 4, 4:09 PM CDTTornado WarningMOBWashington36 min
Sep 4, 4:15 PM CDTTornado WarningMOBBaldwin, Escambia60 min
Sep 4, 4:28 PM CDTTornado WarningMOBBaldwin49 min

Nearby

Tornado Warnings in Alabama, 2011Every tornado warning in 2011Tornadoes 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.