Alert archive / Alabama / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 204, NWS Mobile, AL

September 30, 2012Washington County, Alabama

NWS Mobile, AL issued this severe thunderstorm warning at Sep 30, 2012, 11:10 PM CDT for Washington County, Alabama. It was in force for 50 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 30, 2012, 11:10 PM CDT (04:10 UTC)
Expired
Oct 1, 2012, 12:00 AM CDT
In force
50 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon

County Washington County, AL

The radar

The Mobile radar (KMOB), 86 km from the middle of the area, began a volume at 04:10 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 30, 5:50 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 4.2 hours before the alert went out and 199 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 00:00Z on 2012-10-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1860 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 00:00Z on 2012-10-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 235 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
1860 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
486 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
235 m²/s²
0-3 km storm-relative helicity
248 m²/s²
Significant tornado parameter
1.8
Supercell composite
12.4

Open this sounding in Storm Lab

The text

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

434 
WUUS54 KMOB 010410
SVRMOB
ALC129-010500-
/O.NEW.KMOB.SV.W.0204.121001T0410Z-121001T0500Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOBILE AL
1110 PM CDT SUN SEP 30 2012

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WASHINGTON COUNTY IN SOUTHWEST ALABAMA...

* UNTIL MIDNIGHT CDT

* AT 1105 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING
  DAMAGING WINDS OVER 60 MPH WAS LOCATED 11 MILES SOUTH OF CHATOM...
  OR 4 MILES SOUTHEAST OF TIBBIE...AND MOVING NORTHEAST AT 35 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WAGARVILLE...         VINEGAR BEND...       TIBBIE...
  SAINT STEPHENS...     MILLRY...             MCINTOSH...
  LEROY...              DEER PARK...          CHATOM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEEK SAFE SHELTER INDOORS IF YOU ARE IN THE PATH OF THIS STORM. 

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. REMEMBER...
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES.

&&

LAT...LON 3160 8808 3148 8791 3114 8809 3117 8840
      3168 8837
TIME...MOT...LOC 0409Z 211DEG 30KT 3134 8820

$$
1 follow-up statement
184 
WWUS54 KMOB 010432
SVSMOB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
1132 PM CDT SUN SEP 30 2012

ALC129-010500-
/O.CON.KMOB.SV.W.0204.000000T0000Z-121001T0500Z/
WASHINGTON AL-
1132 PM CDT SUN SEP 30 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT
FOR WASHINGTON COUNTY...

AT 1128 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING
WINDS OVER 60 MPH WAS LOCATED 10 MILES SOUTHEAST OF CHATOM...OR 7
MILES SOUTHWEST OF WAGARVILLE...MOVING NORTHEAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  WAGARVILLE...         TIBBIE...             SAINT STEPHENS...
  MILLRY...             MCINTOSH...           LEROY...
  CHATOM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. PREPARE FOR DAMAGING WINDS. PEOPLE OUTSIDE
SHOULD MOVE INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. SEVERE 
THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. IF A 
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY.

&&

LAT...LON 3160 8808 3148 8791 3122 8805 3135 8839
      3168 8837
TIME...MOT...LOC 0432Z 224DEG 22KT 3140 8810

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 30, 9:49 PM CDTSpecial Marine WarningMOB86 min
Oct 1, 12:44 AM CDTSpecial Marine WarningMOB91 min
Oct 1, 9:20 AM CDTRip Current StatementMOB15 hr

Nearby

Severe Thunderstorm Warnings in Alabama, 2012Every severe thunderstorm 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.