Alert archive / Alabama / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 310, NWS Birmingham, AL

December 25, 20124 counties in Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Dec 25, 2012, 6:45 PM CST for 4 counties in Alabama. It was in force for 30 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: Dec 25, 2012, 6:45 PM CST (00:45 UTC)
Expired: Dec 25, 2012, 7:15 PM CST
In force: 30 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon

Counties Bibb County, AL, Chilton County, AL, Perry County, AL, Shelby County, AL

The radar

The Birmingham radar (KBMX), 35 km from the middle of the area, began a volume at 00:47 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.

Issued	Product	Office	Lasted
Dec 25, 12:58 PM CST	Tornado Watch PDS	SPC	9 hr
Dec 25, 4:38 PM CST	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 0.8 hours before the alert went out and 35 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: 22 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 563 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 696 m²/s²
0-3 km storm-relative helicity: 921 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

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

808 
WUUS54 KBMX 260045
SVRBMX
ALC007-021-105-117-260115-
/O.NEW.KBMX.SV.W.0310.121226T0045Z-121226T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
645 PM CST TUE DEC 25 2012

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BIBB COUNTY IN ALABAMA...
  WEST CENTRAL CHILTON COUNTY IN ALABAMA...
  NORTHEASTERN PERRY COUNTY IN ALABAMA...
  SOUTHWESTERN SHELBY COUNTY IN ALABAMA...

* UNTIL 715 PM CST

* AT 642 PM CST...THE NATIONAL WEATHER SERVICE INDICATED A LINE OF
  SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM
  BRENT TO 6 MILES SOUTHEAST OF HARRISBURG...AND MOVING NORTHEAST AT
  50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  BRENT...CENTREVILLE...WEST CENTREVILLE...TALLADEGA NATIONAL
  FOREST...LAWLEY...ASHBY...CHILTON COUNTY MOTOR SPORTS PARK AND
  BRIERFIELD IRONWORKS PARK.

WINDS OF 60 TO 70 MPH WILL BREAK LARGE TREE LIMBS AND CAUSE SOME
DAMAGE...ESPECIALLY TO SMALLER STRUCTURES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION...MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF
YOUR HOME OR BUSINESS.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM CST TUESDAY EVENING
FOR SOUTHERN ALABAMA.

TO REPORT SEVERE WEATHER...
CALL 1-800-856-0758 OR TWEET YOUR REPORT USING HASHTAG ALWX

LAT...LON 3320 8699 3285 8674 3274 8723 3292 8738
TIME...MOT...LOC 0045Z 243DEG 42KT 3296 8719 3282 8713

$$

14

1 follow-up statement

140 
WWUS54 KBMX 260057
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
657 PM CST TUE DEC 25 2012

ALC105-260107-
/O.CAN.KBMX.SV.W.0310.000000T0000Z-121226T0115Z/
PERRY AL-
657 PM CST TUE DEC 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PERRY COUNTY IS
CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE 
WARNED AREA.

TO REPORT SEVERE WEATHER...CALL 1-800-856-0758.

LAT...LON 3320 8699 3285 8674 3283 8708 3284 8713
      3307 8717
TIME...MOT...LOC 0057Z 243DEG 42KT 3302 8704 3288 8698

$$

ALC007-021-117-260115-
/O.CON.KBMX.SV.W.0310.000000T0000Z-121226T0115Z/
BIBB AL-CHILTON AL-SHELBY AL-
657 PM CST TUE DEC 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHWESTERN
SHELBY...CENTRAL CHILTON AND EASTERN BIBB COUNTIES UNTIL 715 PM
CST...

AT 656 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM 5 MILES NORTHEAST OF CENTREVILLE TO TALLADEGA NATIONAL FOREST...
MOVING NORTHEAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  ASHBY...CHILTON COUNTY MOTOR SPORTS PARK...BRIERFIELD IRONWORKS
  PARK...SIX MILE...RANDOLPH...MARVEL AND CAMPBELL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

TO REPORT SEVERE WEATHER...CALL 1-800-856-0758.

LAT...LON 3320 8699 3285 8674 3283 8708 3284 8713
      3307 8717
TIME...MOT...LOC 0057Z 243DEG 42KT 3302 8704 3288 8698

$$

14

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 25, 6:10 PM CST	Severe Thunderstorm Warning	BMX	Dallas, Marengo, Perry	37 min
Dec 25, 6:15 PM CST	Severe Thunderstorm Warning	BMX	Chilton, Hale, Perry	45 min
Dec 25, 6:33 PM CST	Special Weather Statement	BMX	Bibb, Chilton, Jefferson, Shelby	57 min
Dec 25, 6:40 PM CST	Special Weather Statement	BMX	Pike	35 min
Dec 25, 6:44 PM CST	Tornado Warning	BMX	Barbour, Bullock, Pike	46 min
Dec 25, 7:00 PM CST	Areal Flood Advisory	BMX	Bibb, Chilton, Dallas, Jefferson, Perry, Shelby	3 hr
Dec 25, 7:08 PM CST	Severe Thunderstorm Warning	BMX	Autauga, Bibb, Chilton, Dallas, Perry, Shelby	52 min
Dec 25, 7:31 PM CST	Severe Thunderstorm Warning	BMX	Dallas, Lowndes	59 min
Dec 25, 7:34 PM CST	River Flood Warning	BMX	Sumter	7 hr
Dec 25, 7:38 PM CST	Severe Thunderstorm Warning	BMX	Autauga, Chilton, Clay, Coosa, Talladega	41 min
Dec 25, 7:58 PM CST	Special Weather Statement	BMX	Clay, Talladega	47 min
Dec 25, 8:07 PM CST	Tornado Warning	BMX	Lowndes	46 min
Dec 25, 8:40 PM CST	Tornado Warning	BMX	Autauga, Elmore, Montgomery	65 min
Dec 25, 9:51 PM CST	Severe Thunderstorm Warning	BMX	Montgomery	39 min
Dec 25, 10:18 PM CST	Tornado Warning	BMX	Pike	42 min
Dec 25, 10:22 PM CST	Severe Thunderstorm Warning	BMX	Bullock	38 min
Dec 25, 10:45 PM CST	Severe Thunderstorm Warning	BMX	Macon	45 min
Dec 25, 10:48 PM CST	Severe Thunderstorm Warning	BMX	Bullock, Pike	42 min
Dec 25, 11:24 PM CST	Special Weather Statement	BMX	Barbour, Lee, Russell	66 min
Dec 26, 12:14 AM CST	Special Weather Statement	BMX	Barbour	31 min
Dec 26, 8:57 AM CST	River Flood Warning	BMX	Greene, Hale, Marengo	24 hr

Nearby

Severe Thunderstorm Warnings in Alabama, 2012 Every 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.