Severe Thunderstorm Warning 154, NWS Baltimore/Washington

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
330 PM EDT TUE JUL 9 2002

...SHORT TERM (TONIGHT-WED NGT)...

12Z MDLS MORE IN LINE THAN PREVIOUS RUNS WITH TIMING OF COLD FRONT
THAT WILL BE MOVING THROUGH THE REGION TONIGHT. BOTH THE 12Z ETA AND
AVN ARE IN LINE WITH THE AVN PICKING UP THE TIMING OF THE FRONT.
E-W-ORIENTED FRONTS TYPICALLY LAG A LITTLE...BUT THE CENTER OF HIGH
PRES OVER THE ERN GRT LAKES...1026 MB...IS PRETTY STRONG FOR THIS
TIME OF YEAR. ANY HIGH CENTER OF 1020 OR GREATER WILL NEARLY ALWAYS
PUSH A FRONT WELL S OF THE REGION...AS WILL BE THE CASE TONIGHT.

UNFORTUNATELY...OUR RAIN CHANCES STILL LOOK PRETTY SLIM...ALTHOUGH
FOR THIS PCKG I UPPPED THE POPS TO LKLY FOR TONIGHT OWING WHAT IS ON
RADAR NOW. THERE WILL BE NARROW LINES OF RW/TRW OVERNIGHT. ONE
INSTABLILITY AREA IS OVER W-CNTRL VA ATTM. THIS AREA WILL MOVE AWAY
FROM THE CWA SHORTLY. THEN A SECOND INSTABILITY LINE AHEAD OF THE
FRONT WAS JUST CROSSING THE OH RIVER INTO WV/PA. IT REMAINS
UNCERTAIN HOW MUCH SUPPORT THIS LINE WILL HAVE BY THE TIME IT MAKES
IT INTO OUR WRN ZNS LATER THIS EVENING. SFC DEW PTS HAVE RECOVERED
INTO THE U60S E OF THE BLUE RIDGE THIS AFTERNOON AND WL REMAIN THERE
OVERNIGHT.

FOR WED...HV DROPPED POPS OVER THE NRN 2/3RDS OF THE REGION BUT KEPT
A 30 CHC ACROSS THE SRN AREA THROUGH THE MORNING. DRIER AIR WL THEN
FILTER INTO THE REGION WED AFTN. TEMPS WL BE COOLER ON WED BY ABOUT
2 CATEGORIES.

WED NIGHT...JUST A FEW HIGH CLDS...AND WITH RELATIVELY DRY AIR IN
PLACE EXPECT TEMPS TO BE ON THE COOL SIDE COMPARED TO CLIMO.

SMZ

THU THRU TUE...

DRY NW FLOW WL BE OVR MID ATLC RGN THU AND THU NGT AS SFC HIGH PRES
BLDS SE INTO THE AREA. INFLUX OF COOL AIR FM THE N WL KEEP TEMPS BLO
NORMAL. GUIDANCE PROGS MAXES ONLY IN U70S ON THU. COOLG WL BE OFFSET
BY M/S SKIES HOWEVER SO WL CONT PREV FCST OF TEMPS IN L80S. LGT WNDS
AND SKC THU NIGHT WL PERMIT DECENT TEMP FALL SO LOWERED MINS INTO
L50S FAR W AND M50S ELSW.

LEFT RMNDR OF EXTENDED FCST UNCHGD. MOISTURE WL BGN INCRG OVR THE
AREA AGN LATE FRI AS UPR FLOW BCMS SW AHD OF S/W OVR MIDWEST. WAA
MOVS OVR RGN FRI NGT AND SAT AHD OF LOW PRES IN TN VLLY. PC FCST FOR
FRI W/L80S STILL LUKS RSNBL...W/NXT CHC FOR PCPN OVR THE WEEKEND.
PCPN MAY MOV OUT OF FA SUN MORN BUT WL WAIT FOR FUTURE MDL RUNS BFR
FINE TUNING THE TIMING.

DRY WX WL RETURN FOR MON AND TUE AS UPR RDG BLDS OVR AREA BHND
DEPARTING S/W.

ARTHUR

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