Alert archive / Alabama / Tornado Warnings in 2011

Tornado Warning 31, NWS Mobile, AL

April 15, 2011Washington County, Alabama

NWS Mobile, AL issued this tornado warning at Apr 15, 2011, 10:20 AM CDT for Washington County, Alabama. It was in force for 40 min. 1 report 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
Apr 15, 2011, 10:20 AM CDT (15:20 UTC)
Expired
Apr 15, 2011, 11:00 AM CDT
In force
40 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon

County Washington County, AL

The radar

The Mobile radar (KMOB), 66 km from the middle of the area, began a volume at 15:23 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
Apr 15, 11:00 AM CDTHAIL 1.75Sunflower, ALGOLFBALL SIZE HAIL REPORTED BY PUBLIC.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 15, 7:32 AM CDTTornado WatchSPC7 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 3.3 hours before the alert went out and 181 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 2011-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2339 joules per kilogram.LCLEL10008507005003002001001 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, Slidell Radar S, LA at 12:00Z on 2011-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 325 square meters per square second.19395878Sfc1 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
2339 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
499 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
325 m²/s²
0-3 km storm-relative helicity
504 m²/s²
Significant tornado parameter
4.8
Supercell composite
21.3

Open this sounding in Storm Lab

The text

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

463 
WFUS54 KMOB 151520
TORMOB
ALC129-151600-
/O.NEW.KMOB.TO.W.0031.110415T1520Z-110415T1600Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOBILE AL
1020 AM CDT FRI APR 15 2011

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* TORNADO WARNING FOR...
  WASHINGTON COUNTY IN SOUTHWEST ALABAMA...
  THIS INCLUDES THE CITY OF CHATOM...

* UNTIL 1100 AM CDT

* AT 1019 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 7 MILES
  NORTHWEST OF CITRONELLE...OR 15 MILES NORTHWEST OF PINEOLA...MOVING
  NORTHEAST AT 30 MPH.

* THE TORNADO WILL BE NEAR...
  CORTELUOU AROUND 1100 AM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
GOLFBALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE 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 300 PM CDT FRIDAY AFTERNOON
FOR SOUTHWEST ALABAMA AND SOUTHEAST MISSISSIPPI.

&&

LAT...LON 3137 8790 3115 8825 3115 8833 3112 8833
      3116 8844 3118 8844 3166 8816
TIME...MOT...LOC 1520Z 229DEG 26KT 3115 8834

$$
1 follow-up statement
488 
WWUS54 KMOB 151529
SVSMOB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
1029 AM CDT FRI APR 15 2011

ALC129-151600-
/O.CON.KMOB.TO.W.0031.000000T0000Z-110415T1600Z/
WASHINGTON AL-
1029 AM CDT FRI APR 15 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1100 AM CDT FOR
WASHINGTON COUNTY...

AT 1023 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS
TORNADO WAS NEAR DEER PARK...OR ABOUT 7 MILES NORTHWEST OF
CITRONELLE...MOVING NORTHEAST AT 30 MPH.

THE TORNADO WILL BE NEAR...
  SIMS CHAPEL AND TIBBIE AROUND 1045 AM CDT...
  TOPTON AND SEABOARD AROUND 1050 AM CDT...
  HAWTHORN...TOINETTE...SUNFLOWER AND CORTELYOU AROUND 1100 AM CDT...

IF YOU ARE IN MOBILE HOME...EVACUATE IT AND GET ON THE LOWEST FLOOR
OF A NEARBY STURDY BUILDING OR IN AN UNDERGROUND STORM SHELTER. IF NO
SUBSTANTIAL SHELTER IS AVAILABLE AND A TORNADO IS FAST APPROACHING...
SEEK SHELTER IN A CULVERT...OR LIE FLAT IN THE NEAREST DITCH OR OTHER
LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
GOLF BALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 300 PM CDT FRIDAY AFTERNOON
FOR SOUTHWEST ALABAMA AND SOUTHEAST MISSISSIPPI.

LAT...LON 3115 8831 3117 8840 3121 8841 3166 8816
      3137 8790 3115 8825
TIME...MOT...LOC 1529Z 229DEG 26KT 3119 8828

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 14, 10:41 PM CDTSmall Craft AdvisoryMOB44 hr
Apr 15, 10:50 AM CDTTornado WarningMOBClarke, Washington40 min
Apr 15, 10:56 AM CDTTornado WarningMOBChoctaw49 min
Apr 15, 11:09 AM CDTTornado WarningMOBWashington51 min
Apr 15, 11:26 AM CDTTornado WarningMOBClarke, Monroe49 min
Apr 15, 11:41 AM CDTTornado WarningMOBChoctaw64 min
Apr 15, 11:52 AM CDTTornado WarningMOBChoctaw, Clarke, Washington38 min
Apr 15, 12:07 PM CDTTornado WarningMOBMonroe38 min
Apr 15, 12:20 PM CDTTornado WarningMOBChoctaw, Clarke, Washington40 min
Apr 15, 12:35 PM CDTTornado WarningMOBMonroe, Wilcox24 min
Apr 15, 12:44 PM CDTTornado WarningMOBWashington46 min
Apr 15, 12:51 PM CDTTornado WarningMOBClarke, Wilcox33 min
Apr 15, 1:09 PM CDTTornado WarningMOBWashington51 min
Apr 15, 1:22 PM CDTTornado WarningMOBClarke, Washington21 min
Apr 15, 1:46 PM CDTTornado WarningMOBClarke, Washington44 min
Apr 15, 2:06 PM CDTSevere Thunderstorm WarningMOBChoctaw27 min
Apr 15, 2:22 PM CDTTornado WarningMOBClarke, Monroe, Wilcox38 min
Apr 15, 2:55 PM CDTTornado WarningMOBMonroe, Wilcox50 min
Apr 15, 3:18 PM CDTTornado WarningMOBButler, Conecuh, Monroe, Wilcox57 min
Apr 15, 3:41 PM CDTTornado WarningMOBClarke, Washington32 min
Apr 15, 4:02 PM CDTTornado WarningMOBChoctaw58 min
Apr 15, 4:27 PM CDTTornado WarningMOBClarke, Monroe48 min
Apr 15, 4:57 PM CDTTornado WarningMOBChoctaw42 min
Apr 15, 5:09 PM CDTTornado WarningMOBButler, Conecuh, Monroe, Wilcox51 min
Apr 15, 5:44 PM CDTTornado WarningMOBMonroe, Wilcox31 min
Apr 15, 5:47 PM CDTTornado Warning EmergencyMOBChoctaw58 min
Apr 15, 5:54 PM CDTTornado WarningMOBWilcox51 min
Apr 15, 5:59 PM CDTTornado WarningMOBButler26 min
Apr 15, 6:23 PM CDTTornado WarningMOBWilcox32 min
Apr 15, 6:34 PM CDTTornado WarningMOBChoctaw41 min
Apr 15, 6:44 PM CDTTornado WarningMOBChoctaw, Clarke, Washington61 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.