Alert archive / Alabama / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 25, NWS Birmingham, AL

February 28, 2011Bibb County, Shelby County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Feb 28, 2011, 2:59 PM CST for Bibb County, Shelby County, Alabama. It was in force for 61 min. 4 reports 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: Feb 28, 2011, 2:59 PM CST (20:59 UTC)
Expired: Feb 28, 2011, 4:00 PM CST
In force: 61 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon

Counties Bibb County, AL, Shelby County, AL

The radar

The Birmingham radar (KBMX), 13 km from the middle of the area, began a volume at 20:59 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

Time	Report	Where	Remark
Feb 28, 3:05 PM CST	HAIL 1.5	1 N Chelsea, AL	HAIL AS LARGE AS PING PONG BALLS IN BROOK HIGHLAND.
Feb 28, 3:26 PM CST	TSTM WND DMG	Montevallo, AL	LARGE OLD OAK TREE WAS BLOWN DOWN ONTO A HOME.
Feb 28, 3:36 PM CST	TSTM WND DMG	2 Ne Harpersville, AL	TREE DOWN AT HIGHWAY 25 AT LOW ROAD AND MYRTLEWOOD DRIVE.
Feb 28, 3:36 PM CST	TSTM WND DMG	2 Sse Vincent, AL	AT LEAST 5 TREES WERE EITHER SNAPPED OFF OR UPROOTED NEAR VINCENT. SOME TREE DAMAGE ALSO OCCURRED NEAR VINCENT ELEMENTARY SCHOOL AND ONE TREE WAS BLOWN DOWN AT HIGHWAY 25 AT LOW ROAD AND MYRTLEWOOD DRIVE. THERE WAS NO EVIDENCE OF A TORNADO AT THIS LOCATION.

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.

Issued	Product	Office	Lasted
Feb 28, 12:29 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 9.0 hours before the alert went out and 13 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: 652 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 498 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 256 m²/s²
0-3 km storm-relative helicity: 425 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 5.9

Open this sounding in Storm Lab

The text

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

245 
WUUS54 KBMX 282059
SVRBMX
ALC007-117-282200-
/O.NEW.KBMX.SV.W.0025.110228T2059Z-110228T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
259 PM CST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN BIBB COUNTY IN CENTRAL ALABAMA...
  SHELBY COUNTY IN CENTRAL ALABAMA...

* UNTIL 400 PM CST

* AT 254 PM CST...THE NATIONAL WEATHER SERVICE INDICATED A LINE OF
  SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED
  ALONG A LINE EXTENDING FROM IRONDALE TO BEVILLE LOCK AND DAM...AND
  MOVING EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  HELENA...PELHAM...ALABASTER...CHELSEA...MONTEVALLO...CALERA...
  COLUMBIANA AND WILSONVILLE.

THIS INCLUDES...
INTERSTATE 65 EXIT NUMBERS 228 THROUGH 247...

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 3314 8728 3314 8719 3324 8715 3323 8710
      3325 8698 3353 8652 3355 8652 3354 8649
      3351 8649 3351 8638 3340 8638 3337 8635
      3330 8636 3328 8644 3319 8650 3313 8646
      3305 8657 3308 8662 3306 8731
TIME...MOT...LOC 2059Z 276DEG 42KT 3351 8666 3317 8722

$$

1 follow-up statement

418 
WWUS54 KBMX 282121
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
321 PM CST MON FEB 28 2011

ALC007-117-282200-
/O.CON.KBMX.SV.W.0025.000000T0000Z-110228T2200Z/
BIBB AL-SHELBY AL-
321 PM CST MON FEB 28 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SHELBY AND
NORTH CENTRAL BIBB COUNTIES UNTIL 400 PM CST...

AT 317 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING GOLF BALL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 5 MILES EAST OF VANDIVER TO 8
MILES EAST OF WEST BLOCTON...MOVING EAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  CHELSEA...MONTEVALLO...CALERA...COLUMBIANA...WILSONVILLE...
  WESTOVER...UNIVERSITY OF MONTEVALLO...SHELBY COUNTY AIRPORT...
  VINCENT AND AMERICAN VILLAGE.

THIS INCLUDES...
INTERSTATE 65 EXIT NUMBERS 228 THROUGH 247...

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.

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

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

LAT...LON 3354 8649 3351 8649 3351 8638 3340 8638
      3337 8635 3335 8637 3330 8636 3328 8644
      3319 8650 3313 8646 3305 8657 3308 8662
      3309 8716 3319 8707 3353 8652 3355 8652
TIME...MOT...LOC 2121Z 276DEG 42KT 3348 8637 3315 8694

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 28, 1:53 PM CST	Special Weather Statement	BMX	Marshall	37 min
Feb 28, 2:11 PM CST	Severe Thunderstorm Warning	BMX	Cherokee	34 min
Feb 28, 2:19 PM CST	Special Weather Statement	BMX	Jefferson, Tuscaloosa	41 min
Feb 28, 2:21 PM CST	Severe Thunderstorm Warning	BMX	Cherokee, Etowah	24 min
Feb 28, 2:32 PM CST	Severe Thunderstorm Warning	BMX	Jefferson, Tuscaloosa	43 min
Feb 28, 2:44 PM CST	Severe Thunderstorm Warning	BMX	Cherokee	19 min
Feb 28, 2:58 PM CST	Tornado Warning	BMX	Barbour, Bullock, Pike	15 min
Feb 28, 3:09 PM CST	Severe Thunderstorm Warning	BMX	Calhoun, St. Clair, Talladega	51 min
Feb 28, 3:15 PM CST	Special Weather Statement	BMX	Cherokee	15 min
Feb 28, 3:39 PM CST	Tornado Warning	BMX	Shelby, Talladega	36 min
Feb 28, 3:53 PM CST	Severe Thunderstorm Warning	BMX	Cleburne	37 min
Feb 28, 4:00 PM CST	Severe Thunderstorm Warning	BMX	Clay, Coosa, Randolph, Talladega, Tallapoosa	45 min
Feb 28, 4:16 PM CST	Severe Thunderstorm Warning	BMX	Autauga, Chilton, Dallas	44 min
Feb 28, 4:22 PM CST	Severe Thunderstorm Warning	BMX	Autauga, Dallas, Perry	38 min
Feb 28, 4:43 PM CST	Severe Thunderstorm Warning	BMX	Clay, Randolph	17 min
Feb 28, 4:47 PM CST	Severe Thunderstorm Warning	BMX	Autauga, Dallas, Lowndes	43 min
Feb 28, 5:11 PM CST	Special Weather Statement	BMX	Chambers	49 min
Feb 28, 5:15 PM CST	Severe Thunderstorm Warning	BMX	Dallas, Lowndes, Montgomery	45 min
Feb 28, 5:29 PM CST	Tornado Warning	BMX	Chambers	23 min
Feb 28, 5:56 PM CST	Severe Thunderstorm Warning	BMX	Bullock, Montgomery	49 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2011 Every severe thunderstorm warning 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.