Alert archive / Virginia / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 270

May 9, 2002Somerset County, Maryland; 9 counties in North Carolina; 45 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at May 9, 2002, 6:15 PM EDT for Somerset County, Maryland; 9 counties in North Carolina; 45 counties in Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2002, 6:15 PM EDT (22:15 UTC)
Expired
May 9, 2002, 11:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
All 55 counties

Somerset County, MD, Caswell County, NC, Forsyth County, NC, Granville County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Vance County, NC, Warren County, NC, Yadkin County, NC, Accomack County, VA, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Hopewell, VA, City of Martinsville, VA, City of Petersburg, VA, City of Richmond, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 126 km from the middle of the area, began a volume at 22:17 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

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

IssuedProductOfficeCountiesLasted
May 9, 6:16 PM EDTSevere Thunderstorm WarningRNKHenry, City of Martinsville44 min
May 9, 6:19 PM EDTSevere Thunderstorm WarningAKQCaroline, Hanover31 min
May 9, 6:51 PM EDTSevere Thunderstorm WarningAKQHanover, King William29 min

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 10.3 hours before the alert went out and 101 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, Roanoke, VA at 12:00Z on 2002-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 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, Roanoke, VA at 12:00Z on 2002-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.19395878Sfc1 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
139 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
537 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
128 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 092221
SEL0  
SPC WW 092217 COR
NCZ000-VAZ000-CWZ000-100300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 270...CORRECTED BEGIN TIME
STORM PREDICTION CENTER NORMAN OK
617 PM EDT THU MAY 9 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHERN NORTH CAROLINA
SOUTHEAST VIRGINIA
SOUTHERN CHESAPEAKE BAY
AND ADJACENT COASTAL WATERS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 615 PM UNTIL
1100 PM EDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 75 STATUTE MILES
EAST AND WEST OF A LINE FROM 25 MILES EAST OF GREENSBORO NORTH
CAROLINA TO 40 MILES WEST NORTHWEST OF WALLOPS VIRGINIA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 269.  WATCH NUMBER 269 WILL NOT BE
IN EFFECT AFTER 615 PM EDT.  CONTINUE...WW 270...

DISCUSSION...LINE OF THUNDERSTORMS CONTINUES TO INTENSIFY OVER
CENTRAL VA.  THESE STORMS SHOULD SPREAD EASTWARD ACROSS SOUTHEAST
VA AND NORTHERN NC DURING THE NEXT SEVERAL HOURS.  DAMAGING WINDS
ARE LIKELY THE MAIN THREAT.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 27035.

CORRECTED ISSUANCE TIME.

...HART

380,0744 360,0780 360,0804 380,0773

WWUS20 KWNS 092221
SEL0  
SPC WW 092217 COR
NCZ000-VAZ000-CWZ000-100300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 270...CORRECTED BEGIN TIME
STORM PREDICTION CENTER NORMAN OK
617 PM EDT THU MAY 9 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHERN NORTH CAROLINA
SOUTHEAST VIRGINIA
SOUTHERN CHESAPEAKE BAY
AND ADJACENT COASTAL WATERS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 615 PM UNTIL
1100 PM EDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 75 STATUTE MILES
EAST AND WEST OF A LINE FROM 25 MILES EAST OF GREENSBORO NORTH
CAROLINA TO 40 MILES WEST NORTHWEST OF WALLOPS VIRGINIA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 269.  WATCH NUMBER 269 WILL NOT BE
IN EFFECT AFTER 615 PM EDT.  CONTINUE...WW 270...

DISCUSSION...LINE OF THUNDERSTORMS CONTINUES TO INTENSIFY OVER
CENTRAL VA.  THESE STORMS SHOULD SPREAD EASTWARD ACROSS SOUTHEAST
VA AND NORTHERN NC DURING THE NEXT SEVERAL HOURS.  DAMAGING WINDS
ARE LIKELY THE MAIN THREAT.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 27035.

CORRECTED ISSUANCE TIME.

...HART

380,0744 360,0780 360,0804 380,0773

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 2:30 PM EDTSevere Thunderstorm WatchSPCAllegany, Carroll, Frederick, Garrett, Howard, Montgomery and 1 more5 hr
May 9, 11:30 AM EDTSevere Thunderstorm WatchSPCAshe, Avery, Buncombe, Burke, Caldwell, Cherokee and 16 more6 hr
May 9, 7:00 PM EDTSevere Thunderstorm WatchSPCCabarrus, Catawba, Cleveland, Davidson, Gaston, Iredell and 7 more4 hr
May 9, 11:15 AM EDTTornado WatchSPCBland, Buchanan, Dickenson, Lee, Russell, Scott and 5 more5 hr

Nearby

Severe Thunderstorm Watches in Virginia, 2002Severe Thunderstorm Watches in North Carolina, 2002Severe Thunderstorm Watches in Maryland, 2002Every severe thunderstorm watch in 2002

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.