Alert archive / Alabama / Tornado Watches in 2004

Tornado Watch 916

December 9, 200420 counties in Alabama; 10 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Dec 9, 2004, 4:45 AM CST for 20 counties in Alabama; 10 counties in Mississippi. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Dec 9, 2004, 4:45 AM CST (10:45 UTC)
Expired: Dec 9, 2004, 10:00 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 30 counties

Autauga County, AL, Bibb County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Coosa County, AL, Dallas County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lowndes County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Wilcox County, AL, Clarke County, MS, Jasper County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Wayne County, MS, Winston County, MS

The radar

The Birmingham radar (KBMX), 129 km from the middle of the area, began a volume at 10:44 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 9, 4:58 AM CST	Tornado Warning	JAN	Jasper	47 min
Dec 9, 5:05 AM CST	Severe Thunderstorm Warning	JAN	Lauderdale	55 min
Dec 9, 5:53 AM CST	Tornado Warning	JAN	Noxubee	22 min
Dec 9, 5:57 AM CST	Tornado Warning	BMX	Pickens	33 min
Dec 9, 6:08 AM CST	Severe Thunderstorm Warning	BMX	Greene	37 min
Dec 9, 6:13 AM CST	Flash Flood Warning	BMX	Pickens	2 hr
Dec 9, 6:28 AM CST	Tornado Warning	BMX	Pickens	32 min
Dec 9, 6:35 AM CST	Tornado Warning	BMX	Tuscaloosa	40 min
Dec 9, 7:37 AM CST	Flash Flood Warning	BMX	Jefferson, Shelby	113 min
Dec 9, 7:40 AM CST	Severe Thunderstorm Warning	MOB	Choctaw	35 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, 10.8 hours before the alert went out and 128 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1707 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 68 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.

000 
WWUS20 KWNS 091043
SEL6  
SPC WW 091045
ALZ000-MSZ000-091600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 916
NWS STORM PREDICTION CENTER NORMAN OK
445 AM CST THU DEC 9 2004

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

       CENTRAL ALABAMA
       EAST CENTRAL MISSISSIPPI

EFFECTIVE THIS THURSDAY MORNING FROM 445 AM UNTIL 1000 AM 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 ALONG AND 65 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 30 MILES WEST OF MERIDIAN MISSISSIPPI TO 35
MILES NORTH NORTHEAST OF MONTGOMERY ALABAMA.

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...ORGANIZED CONVECTIVE SYSTEM/SURFACE MESOLOW APPEARS TO
HAVE FORMED ALONG THE SURFACE WARM FRONT BETWEEN JAN AND MEI.  THE
WARM FRONT WILL CONTINUE TO LIFT NWD ACROSS CENTRAL AL...WHICH WILL
MARK THE LIKELY PATH OF THE MESOLOW INTO CENTRAL AL.  BOUNDARY LAYER
DEWPOINTS OF 65-68 F WILL SUPPORT SBCAPE VALUES OF 500-1000 J/KG
ALONG AND S OF THE WARM FRONT...AND LOW-LEVEL SHEAR WILL BE
MAXIMIZED ALONG THIS BOUNDARY. A FEW TORNADOES AND DAMAGING WIND
GUSTS WILL BE THE MAIN SEVERE THREATS WITH COMPLEX SUPERCELL/BOW
ECHO STRUCTURES.

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 500.
MEAN STORM MOTION VECTOR 24040.


...THOMPSON

331,0891 334,0860 314,0860 312,0891

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 9, 4:22 AM CST	Mesoscale Discussion	SPC	Autauga, Baldwin, Chilton, Choctaw, Clarke, Conecuh and 10 more	83 min
Dec 9, 6:04 AM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Choctaw, Clarke, Dallas and 10 more	86 min
Dec 9, 7:46 AM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Choctaw, Clarke, Coosa and 9 more	89 min
Dec 9, 10:24 AM CST	Mesoscale Discussion	SPC	Barbour, Dale, Geneva, Henry, Houston, Russell	2 hr

Nearby

Tornado Watches in Alabama, 2004 Tornado Watches in Mississippi, 2004 Every tornado watch in 2004

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.