Alert archive / Alabama / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 415, NWS Birmingham, AL

September 27, 20114 counties in Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Sep 27, 2011, 7:07 AM CDT for 4 counties in Alabama. It was in force for 26 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 27, 2011, 7:07 AM CDT (12:07 UTC)
Expired
Sep 27, 2011, 7:33 AM CDT
In force
26 min
Issued by
NWS Birmingham, AL
Area
Storm-based polygon

Counties Greene County, AL, Hale County, AL, Pickens County, AL, Tuscaloosa County, AL

The radar

The Columbus AFB radar (KGWX), 95 km from the middle of the area, began a volume at 12:09 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 12:00Z, 0.1 hours before the alert went out and 100 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, Birmingham, AL at 12:00Z on 2011-09-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 894 joules per kilogram.LCLLFCEL10008507005003002001001 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, Birmingham, AL at 12:00Z on 2011-09-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
894 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
553 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

997 
WUUS54 KBMX 271207
SVRBMX
ALC063-065-107-125-271245-
/O.NEW.KBMX.SV.W.0415.110927T1207Z-110927T1245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
707 AM CDT TUE SEP 27 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GREENE COUNTY IN WEST CENTRAL ALABAMA...
  NORTHEASTERN HALE COUNTY IN WEST CENTRAL ALABAMA...
  SOUTHERN PICKENS COUNTY IN WEST CENTRAL ALABAMA...
  SOUTHWESTERN TUSCALOOSA COUNTY IN WEST CENTRAL ALABAMA...

* UNTIL 745 AM CDT

* AT 707 AM CDT...THE NATIONAL WEATHER SERVICE INDICATED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND DAMAGING
  WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR BENEVOLA...
  OR 12 MILES SOUTHEAST OF CARROLLTON...AND MOVING EAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  NORTHPORT...TUSCALOOSA...HOLT...JENA...KNOXVILLE...COKER...LAKE
  LURLEEN STATE PARK AND BRYANT DENNY STADIUM.

THIS INCLUDES...
INTERSTATE 20 EXIT NUMBERS 52 THROUGH 76...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES LEADING KILLERS. REMEMBER...
IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY
LIGHTNING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

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

LAT...LON 3320 8813 3339 8746 3296 8742 3296 8815
TIME...MOT...LOC 1207Z 258DEG 20KT 3315 8793

$$
2 follow-up statements
315 
WWUS54 KBMX 271220
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
720 AM CDT TUE SEP 27 2011

ALC063-065-107-125-271245-
/O.CON.KBMX.SV.W.0415.000000T0000Z-110927T1245Z/
GREENE AL-HALE AL-PICKENS AL-TUSCALOOSA AL-
720 AM CDT TUE SEP 27 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHWESTERN
TUSCALOOSA...EAST CENTRAL PICKENS...NORTHEASTERN HALE AND
NORTHEASTERN GREENE COUNTIES UNTIL 745 AM CDT...

AT 718 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
JENA...OR 11 MILES SOUTH OF GORDO...MOVING EAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  NORTHPORT...TUSCALOOSA...HOLT...KNOXVILLE...COKER...LAKE LURLEEN
  STATE PARK...BRYANT DENNY STADIUM...UNIVERSITY MALL...MCFARLAND
  MALL AND MOUNDVILLE.

THIS INCLUDES...
INTERSTATE 20 EXIT NUMBERS 52 THROUGH 76...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS IF YOU ARE IN
THE PATH OF THIS STORM. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURE'S LEADING KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

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

LAT...LON 3296 8800 3324 8799 3339 8746 3296 8742
TIME...MOT...LOC 1220Z 258DEG 20KT 3316 8785

$$
453 
WWUS54 KBMX 271233
SVSBMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
733 AM CDT TUE SEP 27 2011

ALC063-065-107-125-271242-
/O.CAN.KBMX.SV.W.0415.000000T0000Z-110927T1245Z/
GREENE AL-HALE AL-PICKENS AL-TUSCALOOSA AL-
733 AM CDT TUE SEP 27 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN TUSCALOOSA...EAST
CENTRAL PICKENS...NORTHEASTERN HALE AND NORTHEASTERN GREENE COUNTIES
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED ACROSS THE WARNED 
AREA.

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

LAT...LON 3296 8800 3324 8799 3339 8746 3296 8742
TIME...MOT...LOC 1232Z 258DEG 20KT 3318 8777

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 26, 10:18 PM CDTDense Fog AdvisoryBMXAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 25 more11 hr
Sep 27, 6:26 AM CDTSpecial Weather StatementBMXPickens49 min
Sep 27, 7:33 AM CDTSpecial Weather StatementBMXHale, Tuscaloosa42 min
Sep 27, 7:39 AM CDTSpecial Weather StatementBMXSumter36 min
Sep 27, 8:08 AM CDTSpecial Weather StatementBMXBibb, Jefferson, Perry, Shelby67 min
Sep 27, 8:25 AM CDTSpecial Weather StatementBMXDallas, Marengo65 min
Sep 27, 12:35 PM CDTSpecial Weather StatementBMXBarbour40 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2011Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.