Alert archive / Virginia / Tornado Watches in 2000

Tornado Watch 821

December 17, 20006 states

The Storm Prediction Center issued this tornado watch at Dec 17, 2000, 7:00 AM EST for 6 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Dec 17, 2000, 7:00 AM EST (12:00 UTC)
Expired: Dec 17, 2000, 12:00 PM EST
In force: 5 hr
Issued by: the Storm Prediction Center

All 57 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Calvert County, MD, Caroline County, MD, Cecil County, MD, Dorchester County, MD, Kent County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, 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, City of Chesapeake, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Gloucester County, VA, Isle of Wight County, VA, James City County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, Northumberland County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 106 km from the middle of the area, began a volume at 12:03 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.

Issued	Product	Office	Counties	Lasted
Dec 17, 7:03 AM EST	Flash Flood Warning	PHI	New Castle	3 hr
Dec 17, 7:29 AM EST	Flash Flood Warning	PHI	Delaware	3 hr
Dec 17, 7:42 AM EST	Flash Flood Warning	PHI	Burlington, Camden, Gloucester, Mercer	3 hr
Dec 17, 7:55 AM EST	Severe Thunderstorm Warning	PHI	Burlington, Camden	35 min
Dec 17, 9:25 AM EST	Severe Thunderstorm Warning	PHI	New Castle	35 min
Dec 17, 9:33 AM EST	Flash Flood Warning	PHI	Chester	117 min
Dec 17, 10:00 AM EST	Flash Flood Warning	PHI	New Castle	3 hr
Dec 17, 10:00 AM EST	Flash Flood Warning	PHI	Delaware	3 hr
Dec 17, 11:01 AM EST	Flash Flood Warning	PHI	Burlington, Camden, Gloucester, Mercer	3 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 0.0 hours before the alert went out and 71 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: 341 J/kg
Mixed-layer CIN: -72 J/kg
Mixed-layer LCL: 554 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 394 m²/s²
0-3 km storm-relative helicity: 369 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

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

080 
WWUS9 KMKC 171126
SEL1  

SEL1  
MKC WW 171116
DEZ000-MDZ000-NCZ000-NJZ000-PAZ000-VAZ000-CWZ000-171700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 821
STORM PREDICTION CENTER NORMAN OK
616 AM EST SUN DEC 17 2000

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

   DELAWARE                           
   EASTERN MARYLAND                           
   NORTHEASTERN NORTH CAROLINA                     
   SOUTHERN NEW JERSEY                         
   SOUTHEAST PENNSYLVANIA                       
   EXTREME EASTERN VIRGINIA                           
   ADJACENT COASTAL WATERS                     

EFFECTIVE THIS SUNDAY MORNING FROM 700 AM UNTIL NOON EST.

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 60 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF ELIZABETH CITY NORTH
CAROLINA TO 20 MILES NORTHEAST OF PHILADELPHIA PENNSYLVANIA.

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 819...TORNADO WATCH NUMBER 820.  WATCH NUMBER 819...820 WILL
NOT BE IN EFFECT AFTER 700 AM EST.

DISCUSSION...LINE OF STRONG TO SEVERE STORMS CONTINUE TO MOVE
RAPIDLY NEWD ACROSS AREA.  WINDS CONTINUE TO BE VERY STRONG WITH 60
KT AT LOW LEVELS AND 90 KT AT MID LEVELS.  AIR MASS IS MARGINALLY
UNSTABLE WITH LIFTED INDICES TO -4 OVER NERN NC.  STRONG SPEED
SHEAR INDICATES THE ISOLATED THREAT OF TORNADOES.

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

355,0772 400,0760 400,0735 355,0751

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 17, 2:15 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	Cherokee, Graham, Swain	4 hr
Dec 16, 11:00 PM EST	Tornado Watch	SPC	Bladen, Brunswick, Columbus, New Hanover, Onslow, Pender and 1 more	6 hr
Dec 17, 12:30 AM EST	Tornado Watch	SPC	Anson, Beaufort, Bertie, Camden, Carteret, Chatham and 42 more	7 hr

Nearby

Tornado Watches in Virginia, 2000 Tornado Watches in Maryland, 2000 Tornado Watches in North Carolina, 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; radar from the NEXRAD Level II archive.