Alert archive / Virginia / Tornado Watches in 2005

Tornado Watch 762

August 30, 20055 counties in Maryland; 53 counties in Virginia; Jefferson County, West Virginia

The Storm Prediction Center issued this tornado watch at Aug 30, 2005, 6:35 PM EDT for 5 counties in Maryland; 53 counties in Virginia; Jefferson County, West Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Aug 30, 2005, 6:35 PM EDT (22:35 UTC)
Expired: Aug 31, 2005, 12:00 AM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 59 counties

Calvert County, MD, Charles County, MD, Frederick County, MD, Montgomery County, MD, Prince George's County, MD, Albemarle County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charlotte County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Highland County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Rappahannock County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Jefferson County, WV

The radar

The Sterling radar (KLWX), 66 km from the middle of the area, began a volume at 22:36 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

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

Issued	Product	Office	Counties	Lasted
Aug 30, 6:37 PM EDT	Tornado Warning	LWX	Madison	23 min
Aug 30, 6:46 PM EDT	Tornado Warning	LWX	Albemarle, City of Charlottesville	44 min
Aug 30, 6:59 PM EDT	Tornado Warning	LWX	Madison	22 min
Aug 30, 7:08 PM EDT	Tornado Warning	LWX	Culpeper, Rappahannock	55 min
Aug 30, 7:28 PM EDT	Tornado Warning	LWX	Greene	38 min
Aug 30, 7:51 PM EDT	Tornado Warning	LWX	Fauquier	55 min
Aug 30, 11:14 PM EDT	Severe Thunderstorm Warning	LWX	Frederick	51 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.6 hours before the alert went out and 69 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1066 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 461 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 110 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 302232
SEL2  
SPC WW 302232
DCZ000-MDZ000-VAZ000-CWZ000-310400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 762
NWS STORM PREDICTION CENTER NORMAN OK
635 PM EDT TUE AUG 30 2005

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

       DISTRICT OF COLUMBIA
       CENTRAL MARYLAND
       CENTRAL AND NORTHERN VIRGINIA
       COASTAL WATERS

EFFECTIVE THIS TUESDAY NIGHT FROM 635 PM UNTIL MIDNIGHT 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 APPROXIMATELY ALONG AND 55 STATUTE MILES
EITHER SIDE OF A LINE FROM 15 MILES NORTH NORTHEAST OF WASHINGTON
DISTRICT OF COLUM TO 15 MILES NORTHWEST OF LYNCHBURG VIRGINIA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).

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...CONTINUE...WW 760...WW 761...

DISCUSSION...ISOLATED THUNDERSTORMS OVER CENTRAL VA WILL CONTINUE TO
TRACK NORTHEASTWARD ACROSS THE WATCH AREA FOR SEVERAL MORE HOURS. 
VERY MOIST/TROPICAL AIR MASS...COUPLED WITH INCREASING VERTICAL
SHEAR...WILL POSE THE RISK OF ISOLATED TORNADOES IN STRONGER CELLS.

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 500.
MEAN STORM MOTION VECTOR 23030.


...HART

382,0762 364,0785 380,0795 394,0772

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 30, 12:42 PM EDT	Mesoscale Discussion	SPC	Albemarle, Alleghany, Amherst, Augusta, Bath, Bedford and 45 more	2 hr
Aug 30, 1:25 PM EDT	Tornado Watch	SPC	Alleghany, Bath, Bedford, Bland, Botetourt, Campbell and 27 more	8 hr
Aug 30, 1:55 PM EDT	Tornado Watch	SPC	Buchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more	7 hr
Aug 30, 4:37 PM EDT	Mesoscale Discussion	SPC	Alleghany, Amherst, Appomattox, Bedford, Bland, Botetourt and 30 more	83 min

Nearby

Tornado Watches in Virginia, 2005 Tornado Watches in Maryland, 2005 Tornado Watches in West Virginia, 2005 Every tornado watch in 2005

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.