Alert archive / Florida / Tornado Watches in 2002

Tornado Watch 807

December 24, 200215 counties in Florida

The Storm Prediction Center issued this tornado watch at Dec 24, 2002, 1:30 PM EST for 15 counties in Florida. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 24, 2002, 1:30 PM EST (18:30 UTC)
Expired: Dec 24, 2002, 7:00 PM EST
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Alachua County, FL, Bradford County, FL, Citrus County, FL, Clay County, FL, Dixie County, FL, Flagler County, FL, Gilchrist County, FL, Hernando County, FL, Lake County, FL, Levy County, FL, Marion County, FL, Putnam County, FL, Saint Johns County, FL, Sumter County, FL, Volusia County, FL

The radar

The Jacksonville radar (KJAX), 143 km from the middle of the area, began a volume at 18:30 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

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

Issued	Product	Office	Counties	Lasted
Dec 24, 3:52 PM EST	Tornado Warning	MLB	Volusia	38 min
Dec 24, 3:54 PM EST	Tornado Warning	MLB	Volusia	36 min

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 6.5 hours before the alert went out and 144 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: 101 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 495 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 251 m²/s²
0-3 km storm-relative helicity: 285 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 241826
SEL7  
WWUS20 KWNS 241830
SPC WW 241830
FLZ000-CWZ000-250000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 807
STORM PREDICTION CENTER NORMAN OK
130 PM EST TUE DEC 24 2002

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

   NORTHERN FLORIDA                            
   COASTAL WATERS                     

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 700
PM EST.

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 50 STATUTE MILES EITHER SIDE OF
A LINE FROM 50 MILES SOUTHWEST OF CROSS CITY FLORIDA TO 30 MILES
NORTHEAST OF DAYTONA BEACH FLORIDA.

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 806.  WATCH NUMBER 806 WILL NOT BE IN EFFECT AFTER 130 PM
EST.

DISCUSSION...LINE OF STRONG/SEVERE THUNDERSTORMS HAVE BECOME
ORIENTED E/W ACROSS NERN FL WWD INTO NERN GULF.  LINE WILL SLOWLY
MOVE SWD THRU AFTERNOON. CONTINUED STRONG DEEP LAYER SHEAR WILL
PREVAIL S OF LINE FAVORABLE FOR ISOLATED TORNADIC 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 500. 
MEAN STORM MOTION VECTOR 24035.


...HALES

284,0803 282,0833 295,0834 301,0804

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 24, 3:30 AM EST	Tornado Watch	SPC	Escambia, Okaloosa, Santa Rosa	7 hr
Dec 24, 6:20 AM EST	Tornado Watch	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 8 more	6 hr
Dec 24, 9:20 AM EST	Tornado Watch	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 9 more	5 hr

Nearby

Tornado Watches in Florida, 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; radar from the NEXRAD Level II archive.