Severe Thunderstorm Warning 3, NWS Baltimore/Washington

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1036 AM EDT FRI APR 19 2002

WILL MAKE A FEW MINOR ADJSMTS TO FORECAST. SHWRS BEGINNING TO BREAK
OUT ALREADY IN CULPEPER COUNTY AND MOVING INTO THE WESTERN ZONES.
BASED ON 10AM TMPS WILL LOWER MAX TMPS SLIGHTLY. WINDS SOUTHWEST AT
10 MPH.

STRONG

----------------
320 AM WBCAFDLWX

SHORT TERM: RDG FLATTENING AS SVRL WEAK S/WVS GET EJECTED AHD OF
CDFNT ACRS GRTLKS. AMS AHD OF CDFNT WL BE QUITE UNSTBL AGN TDA...W/
LI/S ARND -4 TO -6 AND B+ 1500-2000 J/KG. WUD APPR THAT BEST INSTAB
WUD BE ERN CWFA DUE TO INSOLATION...HWVR...SPC PROGGED NWRN CWFA
UNDR SLGT RISK DUE TO CDFNT PROVIDING GOOD FOCUS. REGARDLESS...CONDS
RIPE FOR AFTN CNVCTN AGN...W/ AREAL CVRG BEING THE QSTN...NOT RISK.
POPS IN THE CHC RNG...USING SCT WRDG. PWAT STILL NEAR 1.5 INCH...BUT
A 10-20 KT WND FIELD EXISTS IN THE STEERING FLW...SO LESS OF A FLASH
FLOOD THREAT...UNLESS TRAINING OCCURS. CLDS WL BE A LTL MORE
PLENTIFUL TDA...AND FWC/MAV FINALLY CLSR TO ETA 2M TEMPS. FCST WL
CONCUR W/ COMPUTER SOLN.

AVN A BIT QUIKER THAN ETA IN SWEEPING CDFNT THRU TNGT. CONSIDERING
INITIALIZATION AND FLOW BCMG PARALLEL W/ FNT TNGT...PREFER SLOWER
SOLN. THIS WL KEEP THREAT GOING MUCH OF THE NGT AS FRNTL BNDRY WL
PROVIDE FOCUS...SFC DEWPTS STILL 60-65F...PWAT STILL ARND 1.5
INCHES...AND MSTR WL BE ADVECTED AHD OF S/WV RIDING ALNG FRNT. ATMOS
WL STABLIZE THO...AND WL ONLY MNTN CHC SHRA AFTR MDNGT. MIN/T NEAR
DEWPTS.

MSTR ADVECTING ALNG BNDRY W/ MOIST/MARGINALLY UNSTBL AIR JUST TO THE
S WL PERMIT RAFL TO BE ENHANCED AGN TMRW. PREFER WETTER FWC POPS FOR
THIS RSN...AND WENT LIKELY. ONLY CHC THUNDER THO AS GOOD INSTAB
SQUELCHED BY SATURATED AMS. THIS WL ALSO HOLD TEMPS DWN...BUT GIVEN
RECENT HISTORY...WUD APPR THAT FWC/MAV A BIT ON THE COOL SIDE. SINCE
ETA MODEL OF CHOICE THIS PKG...AND STABILITY GRADIENT POISED JUST N
OF M-D LINE...WL ONCE AGN FCST W/ ETA 2M TEMPS...WHICH ARE A CAT OR
TWO ABV MOS GDNC.    HTS

LONG TERM:  COLD FRONT PASSING THROUGH THE AREA ON SATURDAY PROGGED
BY BOTH ETA AND AVN TO BECOME NEARLY STATIONARY JUST TO THE SOUTH OF
US. SOME LIGHT SHOWERS POSSIBLE INTO SATURDAY EVENING ALONG WITH
THIS FRONT. NORTHERLY FLOW BEHIND THIS SYSTEM NOT VERY EFFICIENT IN
CLEARING SKY COVER OVER AREA. ETA/AVN LOW LEVEL RH FIELDS SHOWING
QUITE A BIT OF MOISTURE REMAINING BEHIND THE FRONT... SO WILL GO
WITH MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. FLOW TURNS TO THE
NORTHEAST AND EVENTUALLY EAST ON SUNDAY ALLOWING MARINE LAYER TO
SETTLE IN PLACE. LIGHT RAIN OR DRIZZLE SHOULD CONTINUE THROUGH THE
DAY ON SUNDAY... WITH TEMPS STRUGGLING TO GET OUT OF THE 50S.

AVN... CANADIAN... UKMET AND NOGAPS ALL OFFERING SIMILAR FORECAST
PATTERNS THROUGH NEXT WEEK... THOUGH SOME DIFFERENCES IN TIMING
EXIST FROM MODEL TO MODEL.  WAVE EXPECTED TO DEVELOP ALONG
STATIONARY FRONT SUNDAY NIGHT AND MONDAY... BRINGING THE BEST CHANCE
OF PRECIP FOR THE UPCOMING WEEK. AVN/MRF TRY TO PUSH WAVE THROUGH
THE AREA BY MID MORNING MONDAY... WHILE REST OF THE EXTENDED MODELS
ALL 6-12 HOURS SLOWER. WILL REMOVE TIMING OF PRECIP FROM MONDAYS
FORECAST... BASED ON CONSENSUS FROM CANADIAN/UKMET/NOGAPS. HIGH
PRESSURE BUILDING IN MID WEEK... FOLLOWED BY ANOTHER COLD FRONT
ASSOCIATED WITH A LOW MOVING UP THROUGH THE GREAT LAKES. AVN/MRF
AGAIN ABOUT 6-12 HOURS FASTER THAN THE REST OF THE EXTENDED
MODELS... BRINGING IN PRECIP BY WEDNESDAY EVENING. AVN/MRF RUN TO
RUN COMPARISON SHOWING A SLOWING TREND... COMING IN CLOSER AGREEMENT
TO THE OTHER MODELS. WILL BE REMOVING PRECIP FROM WEDNESDAYS
FORECAST BASED ON AGREEMENT OF CANADIAN/UKMET AND NOGAPS. CHANCE OF
SHOWERS ON THURSDAY AS FRONT MOVES THROUGH THE AREA.  MARGRAF

.LWX...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.

DCZ001-MDZ002>007-009>011-013-014-016>018-VAZ021-025>031-036>042-
050>056-WVZ048>055-200400-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1100 AM EDT FRI APR 19 2002

...SCATTERED THUNDERSTORMS EXPECTED ACROSS THE MID ATLANTIC TODAY...

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE MID
ATLANTIC REGION THIS AFTERNOON AND THIS EVENING. THE THUNDERSTORMS
THIS AFTERNOON AND THIS EVENING COULD PRODUCE SOME HEAVY
DOWNPOURS... FREQUENT LIGHTNING... GUSTY WINDS AND SMALL HAIL.
HAZARDOUS DRIVING CONDITIONS COULD OCCUR DURING THE EVENING RUSH
HOUR AS A RESULT OF THESE STORMS.

THE STORM PREDICTION CENTER HAS INDICATED THAT THERE IS A SLIGHT
RISK FOR SEVERE THUNDERSTORMS TONIGHT FOR WESTERN MARYLAND... THE
NORTHERN SHENANDOAH VALLEY... AND THE POTOMAC HIGHLANDS.
THUNDERSTORMS WILL OCCUR OVER THIS AREA AS A RESULT OF A COLD FRONT
MOVING IN FROM THE NORTHWEST OVERNIGHT. THE PRIMARY THREAT IN THE
SEVERE WEATHER RISK AREA WILL BE DAMAGING WIND.

SKYWARN ACTIVATION MAY BE NECESSARY TONIGHT. STAY TUNED TO NOAA
WEATHER RADIO OR OTHER LOCAL MEDIA OUTLETS FOR FURTHER UPDATES TO
THIS POSSIBLE SEVERE WEATHER EVENT.

STRONG

VAZ027-029-191730-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1231 PM EDT FRI APR 19 2002

A THUNDERSTORM WILL MOVE EAST FROM SOUTHERN SHENANDOAH COUNTY INTO
PAGE COUNTY BETWEEN 12:30 AND 1:30 THIS AFTERNOON. NEW MARKET...
STANLEY... AND LURAY ARE ALL IN THE PATH OF THIS STORM. IT WILL
QUICKLY PRODUCE ONE TO TWO INCHES OF RAIN AND CLOUD TO GROUND
LIGHTNING. ALSO... GUSTY WINDS UP TO 35 MILES AN HOUR AND SMALL HAIL
ARE POSSIBLE. IF YOU ARE OUTDOORS... SEEK SHELTER FROM THIS STORM.

STRONG

VAZ027-029-WVZ055-191730-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1249 PM EDT FRI APR 19 2002

...STRONG THUNDERSTORMS AFFECTING SHENANDOAH VALLEY AND EASTERN WEST
VIRGINIA PANHANDLE...

A THUNDERSTORM WILL MOVE EAST FROM SOUTHERN SHENANDOAH COUNTY INTO
PAGE COUNTY BETWEEN 1:00 AND 1:30 PM THIS AFTERNOON. NEW MARKET...
STANLEY...AND LURAY ARE ALL IN THE PATH OF THIS STORM. ANOTHER
THUNDERSTORM WILL MOVE EAST THROUGH HARDY COUNTY AND WILL AFFECT
AREAS AROUND MOOREFIELD AND LOST RIVER. THESE STORMS WILL QUICKLY
PRODUCE ONE TO TWO INCHES OF RAIN AND CLOUD TO GROUND LIGHTNING.
ALSO...GUSTY WINDS UP TO 35 MILES AN HOUR AND SMALL HAIL ARE
POSSIBLE. IF YOU ARE OUTDOORS... SEEK SHELTER FROM THESE STORMS.

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT
HTTP://WWW.NWS.NOAA.GOV/ER/LWX

ARTHUR/STRONG

VAZ041-051-191845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
150 PM EDT FRI APR 19 2002

...STRONG THUNDERSTORMS AFFECTING CULPEPER AND FAUQUIER COUNTIES...

A THUNDERSTORM WILL MOVE SLOWLY EAST THROUGH SOUTHERN CULPEPER
COUNTY THIS AFTERNOON. RAINFALL AMOUNTS UP TO AN INCH...SMALL HAIL
AND WIND GUSTS IN EXCESS OF 30 MPH WILL ACCOMPANY THIS STORM.

A CLUSTER OF THUNDERSTORMS WILL AFFECT NORTHERN FAUQUIER COUNTY
THROUGH 230 PM. RAINFALL AMOUNTS OF AN INCH PER HOUR...WINDS IN
EXCESS OF 40 MPH AND SMALL HAIL WILL BE POSSIBLE WITH THESE STORMS
AS THEY MOVE THROUGH DELAPLANE...THE PLAINS AND WARRENTON.

RAINFALL AND GUSTY WINDS WILL CREATE POOR VISIBILITY IN THESE AREAS.
USE CAUTION IF YOU WILL BE TRAVELLING THIS AFTERNOON. SEEK SHELTER
FROM THE STORMS INDOORS.

STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER
DETAILS OR UPDATES.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT
HTTP://WWW.NWS.NOAA.GOV/ER/LWX

ARTHUR