Alert archive / Pennsylvania / Tornado Watches in 2002

Tornado Watch 209

May 2, 20024 states

The Storm Prediction Center issued this tornado watch at May 2, 2002, 2:30 PM EDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 2, 2002, 2:30 PM EDT (18:30 UTC)
Expired
May 2, 2002, 9:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
All 67 counties

Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Cambria County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Mifflin County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV, Randolph County, WV, Tucker County, WV

The radar

The Sterling radar (KLWX), 76 km from the middle of the area, began a volume at 18:30 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

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

IssuedProductOfficeCountiesLasted
May 2, 3:10 PM EDTSevere Thunderstorm WarningLWXFairfax, Loudoun35 min
May 2, 3:15 PM EDTSevere Thunderstorm WarningCTPNorthumberland, Union60 min
May 2, 3:25 PM EDTSevere Thunderstorm WarningLWXMontgomery50 min
May 2, 3:44 PM EDTSevere Thunderstorm WarningLWXHoward46 min
May 2, 3:44 PM EDTSevere Thunderstorm WarningCTPAdams61 min
May 2, 3:49 PM EDTSevere Thunderstorm WarningLWXKing George, Spotsylvania, Stafford, City of Fredericksburg26 min
May 2, 4:05 PM EDTSevere Thunderstorm WarningLWXBaltimore, City of Baltimore40 min
May 2, 4:15 PM EDTSevere Thunderstorm WarningCTPYork60 min
May 2, 4:22 PM EDTSevere Thunderstorm WarningLWXHarford38 min
May 2, 4:41 PM EDTSevere Thunderstorm WarningCTPLancaster64 min
May 2, 4:56 PM EDTTornado WarningCTPYork19 min
May 2, 5:15 PM EDTTornado WarningLWXHarford30 min
May 2, 7:33 PM EDTSevere Thunderstorm WarningCTPLancaster42 min

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 6.5 hours before the alert went out and 199 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, Pittsburgh, PA at 12:00Z on 2002-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 406 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, Pittsburgh, PA at 12:00Z on 2002-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 275 square meters per square second.1939587897Sfc1 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
406 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
601 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
275 m²/s²
0-3 km storm-relative helicity
305 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 021827
SEL9  
SPC WW 021823
DCZ000-MDZ000-PAZ000-VAZ000-WVZ000-030100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 209
STORM PREDICTION CENTER NORMAN OK
223 PM EDT THU MAY 2 2002

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

   DISTRICT OF COLUMBIA
   WESTERN AND CENTRAL MARYLAND                           
   SOUTHERN PENNSYLVANIA                       
   NORTHERN VIRGINIA                           
   PANHANDLE OF WEST VIRGINIA                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 900
PM EDT.

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 90 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES SOUTH SOUTHWEST OF MARTINSBURG WEST
VIRGINIA TO 45 MILES NORTH OF HARRISBURG 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...  CONTINUE...WW 207...WW 208...

DISCUSSION...CONVECTION WILL CONTINUE TO INCREASE AHEAD OF STRONG
COLD FRONT MOVING ACROSS WW.  STRONG INSTABILITY AND ENHANCED LOW
LEVEL SHEAR WILL ENHANCE THE THREAT OF SUPERCELLS INCLUDING A FEW
TORNADOES AND SIGNIFICANT WIND DAMAGE.


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 500. 
MEAN STORM MOTION VECTOR 27040.


...EVANS

382,0801 405,0783 405,0750 382,0765

WWUS20 KWNS 021827
SEL9  
SPC WW 021823
DCZ000-MDZ000-PAZ000-VAZ000-WVZ000-030100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 209
STORM PREDICTION CENTER NORMAN OK
223 PM EDT THU MAY 2 2002

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

   DISTRICT OF COLUMBIA
   WESTERN AND CENTRAL MARYLAND                           
   SOUTHERN PENNSYLVANIA                       
   NORTHERN VIRGINIA                           
   PANHANDLE OF WEST VIRGINIA                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 900
PM EDT.

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 90 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES SOUTH SOUTHWEST OF MARTINSBURG WEST
VIRGINIA TO 45 MILES NORTH OF HARRISBURG 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...  CONTINUE...WW 207...WW 208...

DISCUSSION...CONVECTION WILL CONTINUE TO INCREASE AHEAD OF STRONG
COLD FRONT MOVING ACROSS WW.  STRONG INSTABILITY AND ENHANCED LOW
LEVEL SHEAR WILL ENHANCE THE THREAT OF SUPERCELLS INCLUDING A FEW
TORNADOES AND SIGNIFICANT WIND DAMAGE.


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 500. 
MEAN STORM MOTION VECTOR 27040.


...EVANS

382,0801 405,0783 405,0750 382,0765

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 2:45 PM EDTTornado WatchSPCSaint Mary's, Somerset6 hr
May 2, 3:30 PM EDTTornado WatchSPCCalvert, Caroline, Cecil, Dorchester, Kent, Queen Anne's and 1 more6 hr
May 2, 4:30 AM EDTSevere Thunderstorm WatchSPCFayette, Greene, Washington4 hr
May 1, 9:00 PM EDTTornado WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more4 hr
May 1, 11:30 PM EDTSevere Thunderstorm WatchSPCGrayson4 hr
May 2, 9:45 AM EDTTornado WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Wise and 2 more4 hr
May 2, 12:30 PM EDTSevere Thunderstorm WatchSPCAlbemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 45 more5 hr
May 2, 1:30 PM EDTSevere Thunderstorm WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more7 hr
May 2, 4:00 PM EDTTornado WatchSPCMecklenburg5 hr
May 2, 4:30 PM EDTSevere Thunderstorm WatchSPCAppomattox, Bedford, Bland, Botetourt, Campbell, Carroll and 21 more6 hr
May 2, 5:00 PM EDTSevere Thunderstorm WatchSPCAppomattox, Bedford, Bland, Botetourt, Campbell, Carroll and 21 more5 hr

Nearby

Tornado Watches in Pennsylvania, 2002Tornado Watches in Virginia, 2002Tornado Watches in Maryland, 2002Every tornado 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.