Alert archive / Florida / Tornado Watches in 2002

Tornado Watch 817

December 31, 20028 counties in Alabama; 12 counties in Florida; 8 counties in Georgia

The Storm Prediction Center issued this tornado watch at Dec 31, 2002, 7:35 AM CST for 8 counties in Alabama; 12 counties in Florida; 8 counties in Georgia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Dec 31, 2002, 7:35 AM CST (13:35 UTC)
Expired: Dec 31, 2002, 1:00 PM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 28 counties

Coffee County, AL, Conecuh County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Clay County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Miller County, GA, Seminole County, GA

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 31, 9:10 AM CST	Tornado Warning	MOB	Escambia, Santa Rosa	35 min
Dec 31, 9:45 AM CST	Tornado Warning	MOB	Okaloosa	45 min
Dec 31, 9:47 AM CST	Tornado Warning	MOB	Santa Rosa	28 min
Dec 31, 11:20 AM CST	Tornado Warning	TAE	Bay	25 min

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 1.6 hours before the alert went out and 206 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: 1011 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 300 m²/s²
0-3 km storm-relative helicity: 360 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 311337
SEL7  
SPC WW 311335
ALZ000-FLZ000-GAZ000-CWZ000-311900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 817
STORM PREDICTION CENTER NORMAN OK
735 AM CST TUE DEC 31 2002

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

   SOUTHERN ALABAMA                            
   WESTERN AND CENTRAL FLORIDA PANHANDLE                          
   SOUTHWEST GEORGIA                            
   AND ADJACENT COASTAL WATERS                     

EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 735 AM UNTIL 100
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 ALONG AND 90 STATUTE MILES EAST AND WEST
OF A LINE FROM 70 MILES SOUTHWEST OF PANAMA CITY FLORIDA TO 25
MILES NORTH NORTHWEST OF DOTHAN 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO WATCH
NUMBER 816.  WATCH NUMBER 816 WILL NOT BE IN EFFECT AFTER 735 AM
CST.

DISCUSSION...VIGOROUS SQUALL LINE CONTINUES EWD AT AROUND 50 KT. 
LOW LEVEL FLOW IS AROUND 40 KT ACROSS THIS AREA ENHANCING
WARM/MOISTURE ADVECTION.  STRONG SHEAR STILL PRESENT FAVORING HP
TYPE SUPERCELLS.


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 23040.


...MCCARTHY

313,0840 292,0850 292,0880 313,0870

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 31, 2:50 AM CST	Tornado Watch	SPC	Baldwin, Conecuh, Covington, Escambia, Mobile, Washington	5 hr
Dec 31, 12:30 PM CST	Severe Thunderstorm Watch	SPC	Calhoun, Columbia, Gadsden, Gulf, Hamilton, Jefferson and 7 more	6 hr
Dec 31, 3:05 PM CST	Severe Thunderstorm Watch	SPC	Alachua, Charlotte, Citrus, DeSoto, Dixie, Flagler and 24 more	6 hr
Dec 31, 3:55 PM CST	Severe Thunderstorm Watch	SPC	Baker, Bradford, Clay, Columbia, Duval, Hamilton and 4 more	5 hr

Nearby

Tornado Watches in Florida, 2002 Tornado Watches in Alabama, 2002 Tornado Watches in Georgia, 2002 Every tornado watch in 2002

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.