Alert archive / Alabama / Tornado Watches in 2009

Tornado Watch 40

February 28, 200921 counties in Alabama

The Storm Prediction Center issued this tornado watch at Feb 28, 2009, 2:52 AM CST for 21 counties in Alabama. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Feb 28, 2009, 2:52 AM CST (08:52 UTC)
Expired
Feb 28, 2009, 11:49 AM CST
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 21 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Chambers County, AL, Chilton County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Russell County, AL, Sumter County, AL, Tallapoosa County, AL

The radar

The Birmingham radar (KBMX), 59 km from the middle of the area, began a volume at 08:54 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Feb 28, 3:30 AM CSTSevere Thunderstorm WarningBMXGreene, Hale, Pickens, Tuscaloosa45 min
Feb 28, 4:10 AM CSTSevere Thunderstorm WarningBMXBibb, Greene, Hale, Marengo, Pickens, Sumter and 1 more50 min
Feb 28, 4:55 AM CSTSevere Thunderstorm WarningBMXBibb, Chilton, Greene, Hale, Jefferson, Perry and 2 more50 min
Feb 28, 5:34 AM CSTSevere Thunderstorm WarningBMXAutauga, Chilton, Dallas, Hale, Perry41 min
Feb 28, 6:11 AM CSTSevere Thunderstorm WarningBMXAutauga, Chilton, Dallas, Perry49 min
Feb 28, 6:26 AM CSTSevere Thunderstorm WarningBMXChilton, Coosa49 min
Feb 28, 6:42 AM CSTTornado WarningBMXAutauga, Elmore, Lowndes, Macon, Montgomery48 min
Feb 28, 7:25 AM CSTTornado WarningBMXElmore, Lee, Macon, Tallapoosa50 min
Feb 28, 7:53 AM CSTTornado WarningBMXLee, Macon, Russell52 min
Feb 28, 7:59 AM CSTTornado WarningBMXChambers, Lee46 min
Feb 28, 8:48 AM CSTFlash Flood WarningBMXLee3 hr
Feb 28, 8:49 AM CSTSevere Thunderstorm WarningBMXRussell26 min
Feb 28, 9:05 AM CSTSevere Thunderstorm WarningBMXBullock, Lowndes, Macon, Montgomery40 min
Feb 28, 9:46 AM CSTSevere Thunderstorm WarningBMXRussell29 min
Feb 28, 10:01 AM CSTTornado WarningBMXBullock, Macon, Montgomery15 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 8.9 hours before the alert went out and 59 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 00:00Z on 2009-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 30 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2009-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -133 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
30 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
539 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-133 m²/s²
0-3 km storm-relative helicity
61 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.

912 
WWUS20 KWNS 280850
SEL0  
SPC WW 280850
ALZ000-281500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 40
NWS STORM PREDICTION CENTER NORMAN OK
250 AM CST SAT FEB 28 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       CENTRAL ALABAMA

EFFECTIVE THIS SATURDAY MORNING FROM 250 AM UNTIL 900 AM CST.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 50 MILES SOUTHWEST OF
TUSCALOOSA ALABAMA TO 50 MILES EAST NORTHEAST OF MONTGOMERY
ALABAMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 39...

DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO SLOWLY
INCREASE IN COVERAGE ACROSS PARTS OF MS/AL AHEAD OF APPROACHING
UPPER TROUGH.  A SURFACE BOUNDARY EXTENDS FROM SOUTH OF TUSCALOOSA
TO SOUTH OF MONTGOMERY...AND DEMARKS THE NORTHERN EDGE OF RICHER AND
MORE UNSTABLE AIRMASS.  THE REGION ALONG THIS BOUNDARY WILL POSE THE
GREATEST RISK OF SUPERCELLS AND ISOLATED TORNADOES THROUGH MID
MORNING AS IT LIFTS VERY SLOWLY NORTHWARD.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 26035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 27, 6:38 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 30 more97 min
Feb 27, 7:45 PM CSTTornado WatchSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 28 more7 hr
Feb 27, 8:48 PM CSTMesoscale DiscussionSPCColbert, Cullman, Franklin, Lamar, Lauderdale, Lawrence and 4 more117 min
Feb 27, 10:47 PM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Chambers, Chilton and 23 more118 min
Feb 28, 2:15 AM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Chambers, Chilton and 25 more90 min
Feb 28, 5:40 AM CSTMesoscale DiscussionSPCAutauga, Bullock, Butler, Chilton, Choctaw, Clarke and 17 more2 hr
Feb 28, 9:49 AM CSTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Coffee, Conecuh, Covington and 8 more86 min
Feb 28, 10:39 AM CSTTornado WatchSPCCoffee, Covington, Dale, Geneva, Henry, Houston7 hr
Feb 28, 3:57 PM CSTMesoscale DiscussionSPCColbert, Lauderdale4 hr
Feb 28, 5:43 PM CSTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston8 hr

Nearby

Tornado Watches in Alabama, 2009Every tornado watch in 2009

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.