Alert archive / Virginia / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 481

June 27, 20025 states

The Storm Prediction Center issued this severe thunderstorm watch at Jun 27, 2002, 5:45 PM EDT for 5 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jun 27, 2002, 5:45 PM EDT (21:45 UTC)
Expired: Jun 27, 2002, 10:00 PM EDT
In force: 4 hr
Issued by: the Storm Prediction Center

All 82 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Howard 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, Salem County, NJ, Delaware County, PA, York County, PA, Accomack County, VA, Amelia County, VA, Arlington County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, 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, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Gloucester 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 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, Nottoway County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 107 km from the middle of the area, began a volume at 21:47 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

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

Issued	Product	Office	Counties	Lasted
Jun 27, 6:28 PM EDT	Severe Thunderstorm Warning	CTP	York	62 min
Jun 27, 6:43 PM EDT	Severe Thunderstorm Warning	LWX	Prince George's	47 min
Jun 27, 7:18 PM EDT	Severe Thunderstorm Warning	LWX	Calvert, Saint Mary's	57 min
Jun 27, 7:25 PM EDT	Severe Thunderstorm Warning	PHI	Talbot	50 min

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 9.8 hours before the alert went out and 119 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: 1378 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 686 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 272137
SEL1  
SPC WW 272133
DCZ000-DEZ000-MDZ000-NJZ000-VAZ000-CWZ000-280200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 481
STORM PREDICTION CENTER NORMAN OK
533 PM EDT THU JUN 27 2002

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

   DISTRICT OF COLUMBIA
   DELAWARE                           
   MARYLAND                           
   SOUTHERN NEW JERSEY                         
   CENTRAL AND EASTERN VIRGINIA                           
   COASTAL WATERS                     

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 545 PM UNTIL
1000 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 65 STATUTE MILES
EAST AND WEST OF A LINE FROM 60 MILES WEST SOUTHWEST OF NORFOLK
VIRGINIA TO 15 MILES WEST NORTHWEST OF PHILADELPHIA PENNSYLVANIA.

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...  CONTINUE...WW 478...WW 479...WW 480...

DISCUSSION...BROKEN LINE OF STORMS WILL LIKELY BE MAINTAINED AS IT
MOVES ACROSS INSTABILITY AXIS NOW IN PLACE OVER VA AND THE MID
ATLANTIC COAST.  SHEAR IS NOT IMPRESSIVE...THOUGH IT WILL REMAIN
SUFFICIENT FOR LINEAR/MULTICELLULAR ORGANIZATION AND ENHANCE THE
THREAT OF ISOLATED WIND DAMAGE/BOW ECHOES THROUGH THE EVENING.


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.


...EVANS

363,0782 395,0764 395,0741 363,0760

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 27, 2:15 PM EDT	Severe Thunderstorm Watch	SPC	Garrett	6 hr
Jun 27, 2:00 PM EDT	Severe Thunderstorm Watch	SPC	Bergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 7 more	6 hr

Nearby

Severe Thunderstorm Watches in Virginia, 2002 Severe Thunderstorm Watches in Maryland, 2002 Severe Thunderstorm Watches in New Jersey, 2002 Every 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.