Alert archive / Virginia / Tornado Watches in 2000

Tornado Watch 820

December 17, 20005 states

The Storm Prediction Center issued this tornado watch at Dec 17, 2000, 2:15 AM EST for 5 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Dec 17, 2000, 2:15 AM EST (07:15 UTC)
Expired: Dec 17, 2000, 7:00 AM EST
In force: 5 hr
Issued by: the Storm Prediction Center

All 62 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Kent County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA, Accomack County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Petersburg, VA, City of Poquoson, VA, City of Richmond, VA, City of Williamsburg, VA, Dinwiddie County, VA, Essex County, VA, Gloucester County, VA, Hanover County, VA, Henrico County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Surry County, VA, Westmoreland County, VA, York County, VA

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 17, 3:29 AM EST	Tornado Warning	AKQ	Hanover	31 min
Dec 17, 6:06 AM EST	Flash Flood Warning	PHI	Chester	114 min
Dec 17, 6:13 AM EST	Severe Thunderstorm Warning	PHI	Chester	32 min

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 7.3 hours before the alert went out and 73 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 629 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 196 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.

389 
WWUS9 KMKC 170736
SEL0  

SEL0  
MKC WW 170733
VAZ000-NJZ000-PAZ000-DEZ000-MDZ000-171200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 820
STORM PREDICTION CENTER NORMAN OK
133 AM CST SUN DEC 17 2000

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

   EASTERN VIRGINIA                           
   SOUTHERN HALF OF NEW JERSEY                         
   SOUTHEAST PENNSYLVANIA                       
   DELAWARE                           
   EASTERN MARYLAND                           
   AND ADJACENT COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING FROM 115 AM UNTIL 600 AM CST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 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 50 MILES SOUTHEAST OF RICHMOND VIRGINIA TO 15 MILES
WEST NORTHWEST OF LAKEHURST NEW JERSEY.

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 818...WW 819...WW 820...

DISCUSSION...AIR MASS ACROSS ERN PARTS OF THE DELMARVA CONTINUES TO
DESTABILIZE AIR MASS WITH SURFACE DEW POINTS IN THE MID 60S AND
LIFTED INDICES BETWEEN 0 AND -4.  VAD WIND PROFILES CONTINUE TO
SHOW DEEP LAYER SHEAR SUPPORTIVE OF SUPERCELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. 
MEAN STORM MOTION VECTOR 22050.


...MCCARTHY

365,0780 400,0760 400,0730 365,0751

N

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 17, 7:00 AM EST	Tornado Watch	SPC	Kent, New Castle, Sussex	5 hr
Dec 17, 12:00 PM EST	Severe Thunderstorm Watch	SPC	Bergen, Essex, Hudson, Mercer, Middlesex, Monmouth and 5 more	5 hr
Dec 16, 7:00 PM EST	Severe Thunderstorm Watch	SPC	City of Bristol	4 hr
Dec 17, 12:30 AM EST	Tornado Watch	SPC	Brunswick, Greensville, Isle of Wight, Lunenburg, Mecklenburg, Southampton and 9 more	7 hr

Nearby

Tornado Watches in Virginia, 2000 Tornado Watches in Maryland, 2000 Tornado Watches in New Jersey, 2000 Every tornado watch in 2000

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.