Alert archive / Alabama / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 276, NWS Birmingham, AL

August 18, 2012Bibb County, Chilton County, Shelby County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 18, 2012, 6:48 AM CDT for Bibb County, Chilton County, Shelby County, Alabama. It was in force for 24 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: Aug 18, 2012, 6:48 AM CDT (11:48 UTC)
Expired: Aug 18, 2012, 7:12 AM CDT
In force: 24 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon

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

The radar

The Birmingham radar (KBMX), 19 km from the middle of the area, began a volume at 11:50 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 nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 11.8 hours before the alert went out and 19 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: 1024 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 881 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

092 
WUUS54 KBMX 181148
SVRBMX
ALC007-021-117-181230-
/O.NEW.KBMX.SV.W.0276.120818T1148Z-120818T1230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
648 AM CDT SAT AUG 18 2012

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN BIBB COUNTY IN ALABAMA...
  NORTHERN CHILTON COUNTY IN ALABAMA...
  SOUTHERN SHELBY COUNTY IN ALABAMA...

* UNTIL 730 AM CDT

* AT 648 AM CDT...THE NATIONAL WEATHER SERVICE INDICATED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN EXCESS OF 70
  MPH.  THIS STORM WAS LOCATED NEAR WEST BLOCTON...OR 11 MILES NORTH
  OF CENTREVILLE...AND MOVING EAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  MONTEVALLO...ALABASTER...CALERA...JEMISON...COLUMBIANA...
  WILSONVILLE...ASHBY AND BRIERFIELD IRONWORKS PARK.

THIS INCLUDES...
INTERSTATE 65 EXIT NUMBERS 219 THROUGH 238...

WINDS OF 70 TO 80 MPH WILL UPROOT TREES...DOWN POWER LINES AND CAUSE
DAMAGE TO HOMES AND STRUCTURES.

THIS IS A DANGEROUS STORM. IF YOUR ARE IN ITS PATH...PREPARE
IMMEDAITELY FOR DAMAGING WINDS AND DEADLY CLOUD TO GROUND LIGHTNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

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

LAT...LON 3324 8706 3334 8638 3328 8638 3327 8639
      3328 8643 3326 8642 3324 8646 3320 8646
      3320 8648 3318 8651 3312 8646 3309 8651
      3294 8652 3297 8705
TIME...MOT...LOC 1148Z 271DEG 41KT 3312 8705

$$

27

2 follow-up statements

180 
WWUS54 KBMX 181200
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
700 AM CDT SAT AUG 18 2012

ALC007-021-117-181230-
/O.CON.KBMX.SV.W.0276.000000T0000Z-120818T1230Z/
BIBB AL-CHILTON AL-SHELBY AL-
700 AM CDT SAT AUG 18 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN
SHELBY...NORTHERN CHILTON AND NORTHEASTERN BIBB COUNTIES UNTIL 730 AM
CDT...

AT 655 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
60 MPH.  THIS STORM WAS LOCATED NEAR WILTON...OR 5 MILES WEST OF
MONTEVALLO...MOVING EAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
  MONTEVALLO...ALABASTER...CALERA...JEMISON...COLUMBIANA...
  WILSONVILLE...UNIVERSITY OF MONTEVALLO...MAYLENE...AMERICAN VILLAGE
  AND SHELBY COUNTY AIRPORT.

THIS INCLUDES...
INTERSTATE 65 EXIT NUMBERS 219 THROUGH 238...

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

LAT...LON 3324 8706 3334 8638 3328 8638 3327 8639
      3328 8643 3326 8642 3324 8646 3320 8646
      3320 8648 3318 8651 3312 8646 3309 8651
      3294 8652 3297 8705
TIME...MOT...LOC 1200Z 271DEG 41KT 3311 8689

$$

27

296 
WWUS54 KBMX 181212
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
712 AM CDT SAT AUG 18 2012

ALC007-021-117-181222-
/O.CAN.KBMX.SV.W.0276.000000T0000Z-120818T1230Z/
BIBB AL-CHILTON AL-SHELBY AL-
712 AM CDT SAT AUG 18 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN SHELBY...NORTHERN
CHILTON AND NORTHEASTERN BIBB COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

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

LAT...LON 3324 8706 3334 8638 3328 8638 3327 8639
      3328 8643 3326 8642 3324 8646 3320 8646
      3320 8648 3318 8651 3312 8646 3309 8651
      3294 8652 3297 8705
TIME...MOT...LOC 1212Z 271DEG 41KT 3310 8673

$$

27

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 4:34 AM CDT	Special Weather Statement	BMX	Pickens	56 min
Aug 18, 5:04 AM CDT	Severe Thunderstorm Warning	BMX	Pickens	26 min
Aug 18, 5:14 AM CDT	Special Weather Statement	BMX	Greene, Sumter	46 min
Aug 18, 5:27 AM CDT	Severe Thunderstorm Warning	BMX	Greene, Hale, Pickens, Tuscaloosa	48 min
Aug 18, 6:08 AM CDT	Severe Thunderstorm Warning	BMX	Bibb, Hale, Tuscaloosa	52 min
Aug 18, 8:01 AM CDT	Special Weather Statement	BMX	Autauga, Coosa, Elmore	44 min
Aug 18, 4:58 PM CDT	Special Weather Statement	BMX	Sumter	32 min
Aug 18, 5:44 PM CDT	Special Weather Statement	BMX	Marengo	46 min
Aug 18, 6:07 PM CDT	Areal Flood Advisory	BMX	Winston	4 hr
Aug 18, 6:18 PM CDT	Special Weather Statement	BMX	Dallas, Perry	57 min
Aug 18, 6:34 PM CDT	Special Weather Statement	BMX	Bibb	56 min

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.