Alert archive / Florida / Tornado Watches in 2004

Tornado Watch 799

September 5, 200432 counties in Florida; 4 counties in Georgia

The Storm Prediction Center issued this tornado watch at Sep 5, 2004, 6:10 AM EDT for 32 counties in Florida; 4 counties in Georgia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 5, 2004, 6:10 AM EDT (10:10 UTC)
Expired
Sep 5, 2004, 2:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
All 36 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Brevard County, FL, Citrus County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler County, FL, Gilchrist County, FL, Hamilton County, FL, Hernando County, FL, Hillsborough County, FL, Indian River County, FL, Lafayette County, FL, Lake County, FL, Levy County, FL, Madison County, FL, Marion County, FL, Nassau County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Polk County, FL, Putnam County, FL, Saint Johns County, FL, Seminole County, FL, Sumter County, FL, Suwannee County, FL, Union County, FL, Volusia County, FL, Brooks County, GA, Charlton County, GA, Echols County, GA, Lowndes County, GA

The radar

The Jacksonville radar (KJAX), 105 km from the middle of the area, began a volume at 10:12 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

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

IssuedProductOfficeCountiesLasted
Sep 5, 6:16 AM EDTTornado WarningJAXMarion29 min
Sep 5, 7:45 AM EDTTornado WarningJAXClay30 min
Sep 5, 9:16 AM EDTTornado WarningJAXFlagler, Saint Johns14 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

Jacksonville, FL (KJAX), launched 00:00Z, 10.2 hours before the alert went out and 107 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, Jacksonville, FL at 00:00Z on 2004-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2112 joules per kilogram.LCLEL10008507005003002001001 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, Jacksonville, FL at 00:00Z on 2004-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 square meters per square second.193958Sfc1 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
2112 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
585 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
133 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 051014
SEL9  
SPC WW 051010
FLZ000-GAZ000-CWZ000-051800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 799
NWS STORM PREDICTION CENTER NORMAN OK
610 AM EDT SUN SEP 5 2004

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

       CENTRAL AND NORTHERN FLORIDA
       FAR SOUTHEAST GEORGIA
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 610 AM UNTIL 200
PM EDT.

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

THE TORNADO WATCH AREA IS ALONG AND 65 STATUTE MILES EAST AND WEST
OF A LINE FROM 35 MILES EAST NORTHEAST OF VALDOSTA GEORGIA TO 10
MILES WEST SOUTHWEST OF AVON PARK 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 798. WATCH NUMBER 798 WILL NOT BE IN EFFECT AFTER 610
AM EDT. 

DISCUSSION...APPEARS BAROCLINIC ZONE/INSTABILITY GRADIENT IS
SUPPORTING DISCRETE STORMS OVER FAR NORTHERN FL EARLY THIS
MORNING...WHERE STRONG LOW LEVEL SHEAR IS IN PLACE.  THIS
ZONE...FROM NEAR I-4 NWD INTO FAR SRN GA...IS EXPECTED TO CONTAIN A
THREAT OF A FEW TORNADOES INTO THE EARLY AFTERNOON.  OTHER
MINI-SUPERCELLS AND POSSIBLY TORNADOES MAY EVOLVE WITHIN RAINBANDS
INTO CENTRAL FL...NORTH OF HURRICANE/S CENTER...AS DIURNAL HEATING
DESTABILIZES THE BOUNDARY LAYER BY THE MID MORNING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 400. MEAN STORM MOTION VECTOR 07035.


...EVANS

305,0813 273,0802 273,0823 305,0835

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 5:14 AM EDTMesoscale DiscussionSPCAlachua, Brevard, Citrus, DeSoto, Dixie, Flagler and 25 more91 min
Sep 5, 1:40 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 24 more7 hr
Sep 5, 5:09 PM EDTMesoscale DiscussionSPCBaker, Clay, Duval, Flagler, Nassau, Saint Johns2 hr

Nearby

Tornado Watches in Florida, 2004Tornado Watches in Georgia, 2004Every 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.