Alert archive / Florida / Tornado Watches in 2004

Tornado Watch 839

September 25, 200420 counties in Florida

The Storm Prediction Center issued this tornado watch at Sep 25, 2004, 11:10 PM EDT for 20 counties in Florida. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Sep 25, 2004, 11:10 PM EDT (03:10 UTC)
Expired
Sep 26, 2004, 6:00 AM EDT
In force
7 hr
Issued by
the Storm Prediction Center

Counties Brevard County, FL, Flagler County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Highlands County, FL, Indian River County, FL, Lake County, FL, Marion County, FL, Martin County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Polk County, FL, Putnam County, FL, Saint Lucie County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 50 km from the middle of the area, began a volume at 03:09 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

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

IssuedProductOfficeCountiesLasted
Sep 25, 11:58 PM EDTTornado WarningMLBBrevard62 min
Sep 26, 12:28 AM EDTTornado WarningJAXFlagler32 min
Sep 26, 12:35 AM EDTFlash Flood WarningMLBBrevard, Indian River, Martin, Okeechobee, Osceola, Saint Lucie5 hr
Sep 26, 2:30 AM EDTFlash Flood WarningMFLPalm Beach4 hr
Sep 26, 2:32 AM EDTTornado WarningMLBIndian River58 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 00:00Z, 3.2 hours before the alert went out and 167 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, Tampa Bay, FL at 00:00Z on 2004-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 00:00Z on 2004-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 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
77 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
681 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 260312
SEL9  
SPC WW 260310
FLZ000-CWZ000-261000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 839
NWS STORM PREDICTION CENTER NORMAN OK
1110 PM EDT SAT SEP 25 2004

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

       EASTERN FLORIDA PENINSULA
       COASTAL WATERS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1110 PM
UNTIL 600 AM EDT.

TORNADOES...THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS
LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES NORTH NORTHWEST OF DAYTONA BEACH FLORIDA
TO 45 MILES WEST SOUTHWEST OF WEST PALM 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 838. WATCH NUMBER 838 WILL NOT BE IN EFFECT AFTER
1110 PM EDT. 

DISCUSSION...HURRICANE JEANNE MOVING ONSHORE VICINITY ST. LUCIE AND
MARTIN COUNTIES. THE VERY STRONG SHEAR WILL CONTINUE THREAT OF
TROPICAL TORNADOES IN CONVECTIVE BANDS ASSOCIATED WITH JEANNE AS IT
MOVES SLOWLY INLAND.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 07055.


...HALES

295,0802 262,0795 262,0813 295,0821

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 25, 8:48 PM EDTMesoscale DiscussionSPCBrevard, Flagler, Glades, Hendry, Highlands, Indian River and 10 more117 min
Sep 26, 2:37 AM EDTMesoscale DiscussionSPCBrevard, Flagler, Highlands, Indian River, Lake, Marion and 6 more113 min
Sep 26, 4:50 AM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 22 more12 hr
Sep 26, 8:21 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 18 more114 min
Sep 26, 11:13 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 22 more2 hr
Sep 26, 3:11 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 22 more2 hr
Sep 26, 4:25 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 8 more9 hr
Sep 26, 7:16 PM EDTMesoscale DiscussionSPCBaker, Duval, Nassau119 min

Nearby

Tornado Watches in Florida, 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.