Alert archive / Florida / Tornado Watches in 2004
Tornado Watch 798
The Storm Prediction Center issued this tornado watch at Sep 4, 2004, 7:55 PM EDT for 31 counties in Florida. It was in force for 12 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 4, 2004, 7:55 PM EDT (23:55 UTC)
- Expired
- Sep 5, 2004, 8:00 AM EDT
- In force
- 12 hr
- Issued by
- the Storm Prediction Center
All 31 counties
Alachua County, FL, Brevard County, FL, Citrus County, FL, DeSoto County, FL, Dixie County, FL, Flagler County, FL, Gilchrist County, FL, Glades County, FL, Hardee County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Indian River County, FL, Lake County, FL, Levy County, FL, Manatee County, FL, Marion County, FL, Martin County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Pinellas County, FL, Polk County, FL, Putnam County, FL, Saint Johns County, FL, Saint Lucie County, FL, Sarasota County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL
The radar
The Melbourne radar (KMLB), 124 km from the middle of the area, began a volume at 23:55 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
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 8:11 PM EDT | Tornado Warning | MLB | Brevard | 64 min |
| Sep 4, 9:15 PM EDT | Tornado Warning | MLB | Brevard | 30 min |
| Sep 4, 11:11 PM EDT | Tornado Warning | TBW | Polk | 34 min |
| Sep 4, 11:15 PM EDT | Tornado Warning | MLB | Volusia | 60 min |
| Sep 5, 12:31 AM EDT | Tornado Warning | TBW | Hillsborough, Pasco | 29 min |
| Sep 5, 2:40 AM EDT | Tornado Warning | JAX | Putnam, Saint Johns | 50 min |
| Sep 5, 4:51 AM EDT | Tornado Warning | JAX | Saint Johns | 24 min |
| Sep 5, 6:16 AM EDT | Tornado Warning | JAX | Marion | 29 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
Tampa Bay, FL (KTBW), launched 12:00Z, 11.9 hours before the alert went out and 134 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.
- Mixed-layer CAPE
- 372 J/kg
- Mixed-layer CIN
- -151 J/kg
- Mixed-layer LCL
- 1007 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 122 m²/s²
- 0-3 km storm-relative helicity
- 130 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 042353
SEL8
SPC WW 042355
FLZ000-CWZ000-051200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 798
NWS STORM PREDICTION CENTER NORMAN OK
755 PM EDT SAT SEP 4 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL AND NORTHERN FLORIDA PENINSULA
COASTAL WATERS
EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 755 PM UNTIL
800 AM EDT.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 80 STATUTE MILES EAST AND WEST
OF A LINE FROM 20 MILES NORTH NORTHWEST OF GAINESVILLE FLORIDA TO
50 MILES SOUTH 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.
DISCUSSION...RADAR TRENDS SUGGEST AN INCREASE IN CELLULAR CONVECTIVE
ACTIVITY OFF THE EAST COAST OF FL PENINSULA...NORTH OF EYE OF
HURRICANE FRANCES. VERY STRONG VERTICAL SHEAR PROFILES ARE IN PLACE
THROUGHOUT THE PENINSULA...SUGGESTING THAT THREAT OF ISOLATED
TORNADOES WILL INCREASE OVERNIGHT AS FRANCES MAKES LANDFALL.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.
MEAN STORM MOTION VECTOR 07040.
...HART
295,0810 265,0800 265,0823 295,0834SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 7:16 AM EDT | Mesoscale Discussion | SPC | Brevard, Broward, Indian River, Martin, Okeechobee, Palm Beach and 1 more | 89 min |
| Sep 4, 7:30 PM EDT | Mesoscale Discussion | SPC | Alachua, Brevard, Charlotte, Citrus, DeSoto, Flagler and 23 more | 90 min |
Nearby
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.