Alert archive / Virginia / Tornado Watches in 2004

Tornado Watch 797

August 30, 2004Currituck County, North Carolina; 50 counties in Virginia

The Storm Prediction Center issued this tornado watch at Aug 30, 2004, 12:50 PM EDT for Currituck County, North Carolina; 50 counties in Virginia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Aug 30, 2004, 12:50 PM EDT (16:50 UTC)
Expired
Aug 30, 2004, 8:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
All 51 counties

Currituck County, NC, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Lunenburg County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 60 km from the middle of the area, began a volume at 16:52 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

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

IssuedProductOfficeCountiesLasted
Aug 30, 1:27 PM EDTTornado WarningAKQCharles City, Henrico, Prince George, City of Hopewell33 min
Aug 30, 1:35 PM EDTTornado WarningAKQChesterfield25 min
Aug 30, 1:53 PM EDTTornado WarningAKQJames City22 min
Aug 30, 3:35 PM EDTTornado WarningAKQGloucester, James City, York, City of Williamsburg25 min
Aug 30, 3:58 PM EDTFlash Flood WarningAKQChesterfield, Hanover, Henrico, City of Richmond2 hr
Aug 30, 4:01 PM EDTTornado WarningAKQHanover14 min
Aug 30, 4:21 PM EDTTornado WarningAKQHanover, New Kent24 min
Aug 30, 5:54 PM EDTFlash Flood WarningAKQChesterfield, Hanover, Henrico, King William, New Kent, City of Richmond2 hr
Aug 30, 7:58 PM EDTFlash Flood WarningAKQCaroline, Charles City, Chesterfield, Essex, Hanover, Henrico and 4 more2 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 4.8 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, Washington/Dulle, VA at 12:00Z on 2004-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 joules per kilogram.LCLLFCEL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2004-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.1939Sfc1 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
15 J/kg
Mixed-layer CIN
-157 J/kg
Mixed-layer LCL
771 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
52 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 301653
SEL7  
SPC WW 301650
NCZ000-VAZ000-CWZ000-310000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 797
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM EDT MON AUG 30 2004

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

       NORTHEAST NORTH CAROLINA
       SOUTHEAST VIRGINIA
       COASTAL WATERS

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL 800
PM 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 50 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 65 MILES WEST OF RICHMOND VIRGINIA TO 35
MILES EAST NORTHEAST OF NORFOLK VIRGINIA.

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...CENTER OF TD GASTON CONTINUES TO TRACK NORTHEASTWARD
ACROSS NORTHEAST NC.  BANDS OF CONVECTION AHEAD OF CENTER ARE IN
ZONE OF RATHER STRONG LOW LEVEL VERTICAL SHEAR /1KM SHEAR OVER 20
KNOTS/.  SURFACE DEWPOINTS IN THE MID 70S AND POCKETS OF STRONG
DAYTIME HEATING SHOULD AID IN THUNDERSTORM INTENSIFICATION THIS
AFTERNOON.  ISOLATED TORNADOES APPEAR POSSIBLE.

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 14030.


...HART

381,0783 374,0753 362,0753 364,0783

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 29, 9:13 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, Craven, Cumberland, Duplin and 18 more92 min
Aug 30, 12:07 PM EDTMesoscale DiscussionSPCCamden, Chowan, Currituck, Gates, Hertford, Pasquotank and 3 more113 min
Aug 30, 3:06 PM EDTMesoscale DiscussionSPCAccomack, Amelia, Brunswick, Caroline, Charles City, Chesterfield and 45 more114 min
Aug 30, 6:40 PM EDTMesoscale DiscussionSPCAccomack, Amelia, Brunswick, Caroline, Charles City, Chesterfield and 46 more2 hr

Nearby

Tornado Watches in Virginia, 2004Tornado Watches in North Carolina, 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.