Alert archive / South Carolina / Tornado Watches in 2004

Tornado Watch 807

September 6, 20047 counties in Florida; 14 counties in Georgia; 16 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Sep 6, 2004, 7:45 PM EDT for 7 counties in Florida; 14 counties in Georgia; 16 counties in South Carolina. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Sep 6, 2004, 7:45 PM EDT (23:45 UTC)
Expired
Sep 7, 2004, 5:00 AM EDT
In force
9 hr
Issued by
the Storm Prediction Center
All 37 counties

Bradford County, FL, Clay County, FL, Duval County, FL, Flagler County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Charlton County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Screven County, GA, Wayne County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Georgetown County, SC, Hampton County, SC, Jasper County, SC, Orangeburg County, SC, Williamsburg County, SC

The radar

The Jacksonville radar (KJAX), 88 km from the middle of the area, began a volume at 23:47 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

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

IssuedProductOfficeCountiesLasted
Sep 6, 8:06 PM EDTTornado WarningCHSColleton39 min
Sep 6, 8:21 PM EDTTornado WarningJAXClay39 min
Sep 6, 9:47 PM EDTFlash Flood WarningCHSCandler, Evans, Long, Tattnall6 hr
Sep 6, 9:57 PM EDTTornado WarningJAXWayne18 min
Sep 7, 12:58 AM EDTTornado WarningCHSBerkeley47 min
Sep 7, 2:29 AM EDTTornado WarningCHSDorchester46 min
Sep 7, 2:40 AM EDTTornado WarningCHSChatham35 min
Sep 7, 3:08 AM EDTTornado WarningCAECalhoun37 min
Sep 7, 3:13 AM EDTTornado WarningCHSBeaufort, Jasper32 min
Sep 7, 3:21 AM EDTTornado WarningCAEOrangeburg39 min
Sep 7, 3:47 AM EDTTornado WarningCHSDorchester28 min
Sep 7, 4:23 AM EDTTornado WarningCAECalhoun22 min
Sep 7, 4:29 AM EDTTornado WarningCAEOrangeburg31 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 12:00Z, 11.8 hours before the alert went out and 87 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 12:00Z on 2004-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 830 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 12:00Z on 2004-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 235 square meters per square second.19395878Sfc1 km3 km6 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
830 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
235 m²/s²
0-3 km storm-relative helicity
235 m²/s²
Significant tornado parameter
1.1
Supercell composite
4.8

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 062344
SEL7  
SPC WW 062345
FLZ000-GAZ000-SCZ000-CWZ000-070900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 807
NWS STORM PREDICTION CENTER NORMAN OK
745 PM EDT MON SEP 6 2004

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

       NORTHEAST FLORIDA
       EASTERN GEORGIA
       EASTERN SOUTH CAROLINA
       COASTAL WATERS

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 745 PM UNTIL
500 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 75 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES EAST SOUTHEAST OF GAINESVILLE FLORIDA TO
70 MILES NORTH NORTHWEST OF CHARLESTON SOUTH CAROLINA.

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 805...TORNADO WATCH NUMBER 806. WATCH NUMBER 805 806
WILL NOT BE IN EFFECT AFTER 745 PM EDT. 

DISCUSSION...OUTER BANDS OF TS FRANCES CONTINUE TO ROTATE INLAND
INTO FL/GA/SC...WITH THE THREAT OF ISOLATED TORNADOES. VERTICAL
SHEAR PROFILES REMAIN QUITE STRONG...WITH SPINUPS MOST LIKELY IN
STRONGER/MORE ISOLATED CONVECTIVE CELLS.  THREAT CLOSER TO
CIRCULATION CENTER OVER WESTERN GA APPEARS TO HAVE DIMINISHED.

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 12030.


...HART

291,0822 335,0814 335,0791 291,0795

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 8:35 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more9 hr
Sep 6, 12:12 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more2 hr
Sep 6, 4:06 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more84 min
Sep 6, 4:50 AM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 11 more9 hr
Sep 6, 7:48 AM EDTMesoscale DiscussionSPCBrevard, Charlotte, DeSoto, Hardee, Highlands, Lake and 8 more87 min
Sep 6, 7:55 AM EDTTornado WatchSPCBrevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 21 more6 hr
Sep 6, 12:28 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 36 more92 min
Sep 6, 1:20 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 38 more7 hr
Sep 6, 3:55 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 10 more2 hr
Sep 6, 7:12 PM EDTMesoscale DiscussionSPCBaker, Columbia, Duval, Nassau, Union2 hr
Sep 6, 1:21 AM EDTMesoscale DiscussionSPCRichmond84 min
Sep 6, 1:00 PM EDTTornado WatchSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 49 more7 hr

Nearby

Tornado Watches in South Carolina, 2004Tornado Watches in Georgia, 2004Tornado 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.