Alert archive / Alabama / Tornado Watches in 2009

Tornado Watch 3

January 6, 200930 counties in Alabama; 11 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 6, 2009, 2:03 PM CST for 30 counties in Alabama; 11 counties in Mississippi. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jan 6, 2009, 2:03 PM CST (20:03 UTC)
Expired
Jan 6, 2009, 7:00 PM CST
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 41 counties

Baldwin County, AL, Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Cleburne County, AL, Dallas County, AL, DeKalb County, AL, Etowah County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Marengo County, AL, Marshall County, AL, Mobile County, AL, Monroe County, AL, Perry County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Wilcox County, AL, Clarke County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Jones County, MS, Lamar County, MS, Marion County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Birmingham radar (KBMX), 23 km from the middle of the area, began a volume at 20:04 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jan 6, 2:52 PM CSTTornado WarningBMXBlount, Etowah23 min
Jan 6, 3:09 PM CSTFlash Flood WarningBMXBlount, Etowah, St. Clair4 hr
Jan 6, 3:13 PM CSTFlash Flood WarningHUNDeKalb6 hr
Jan 6, 3:14 PM CSTTornado WarningBMXCherokee, Etowah31 min
Jan 6, 3:20 PM CSTTornado WarningHUNDeKalb25 min
Jan 6, 3:40 PM CSTFlash Flood WarningBMXCherokee4 hr
Jan 6, 3:53 PM CSTTornado WarningBMXCherokee16 min
Jan 6, 4:26 PM CSTFlash Flood WarningHUNCullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more7 hr
Jan 6, 4:36 PM CSTTornado WarningMOBWashington24 min
Jan 6, 5:09 PM CSTFlash Flood WarningBMXFayette, Jefferson, Lamar, Marion, Pickens, Tuscaloosa and 2 more3 hr
Jan 6, 5:27 PM CSTTornado WarningBMXCalhoun, Clay, Cleburne33 min
Jan 6, 5:49 PM CSTTornado WarningBMXClay26 min
Jan 6, 6:56 PM CSTFlash Flood WarningBMXBlount, Etowah, St. Clair3 hr

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 12:00Z, 8.1 hours before the alert went out and 22 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 2009-01-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 163 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 12:00Z on 2009-01-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 240 square meters per square second.1939587897117Sfc1 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
163 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
560 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
240 m²/s²
0-3 km storm-relative helicity
258 m²/s²
Significant tornado parameter
0.3
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

205 
WWUS20 KWNS 062003
SEL3  
SPC WW 062003
ALZ000-MSZ000-070100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 3
NWS STORM PREDICTION CENTER NORMAN OK
205 PM CST TUE JAN 6 2009

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

       CENTRAL AND NORTHEAST ALABAMA
       SOUTHEAST MISSISSIPPI

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 205 PM UNTIL
700 PM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES EAST NORTHEAST OF
GADSDEN ALABAMA TO 210 MILES SOUTHWEST OF BIRMINGHAM ALABAMA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

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.

DISCUSSION...THUNDERSTORMS ARE SLOWLY INCREASING ALONG SURFACE
BOUNDARY EXTENDING FROM SOUTHERN MS INTO NORTHEAST AL.  WEAK
THERMODYNAMICS WILL LIKELY LIMIT INITIATION AHEAD OF FRONT. 
HOWEVER...STRONG VERTICAL SHEAR PROFILES INDICATE A RISK OF
SUPERCELLS/BOW STRUCTURES WITH STORMS ALONG BOUNDARY THROUGH THE
AFTERNOON AND EVENING.  DAMAGING WINDS AND ISOLATED TORNADOES APPEAR
TO BE THE MAIN THREATS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.
MEAN STORM MOTION VECTOR 25030.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 6, 9:43 AM CSTMesoscale DiscussionSPCBaldwin, Butler, Choctaw, Clarke, Conecuh, Dallas and 8 more2 hr
Jan 6, 3:57 PM CSTMesoscale DiscussionSPCAutauga, Bibb, Calhoun, Cherokee, Chilton, Choctaw and 12 more93 min

Nearby

Tornado Watches in Alabama, 2009Tornado Watches in Mississippi, 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.