FXUS61 KLWX 272002
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
302 PM EST FRI NOV 27 2009
.SYNOPSIS...
LOW PRESSURE OFF THE NORTHEAST COAST WILL MOVE UP INTO THE
CANADIAN MARITIMES SATURDAY. HIGH PRESSURE WILL COVER THE MID
ATLANTIC STATES THIS WEEKEND...THEN A COLD FRONT WILL MOVE ACROSS
THE REGION ON MONDAY. HIGH PRESSURE RETURNS ON TUESDAY. LOW
PRESSURE WILL LIKELY IMPACT THE AREA DURING THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
BREEZY DAY ACROSS THE REGION. SCATTERED SHOWERS HAVE /FOR THE MOST
PART/ EXITED THE AREA AND OFF TO THE SE. ISOLATED AND MUCH LIGHTER
SHOWERS WILL CONTINUE TO STREAM DOWN THE POTOMAC RVR VLY FROM THE
POTOMAC HIGHLANDS THRU THE NEXT SEVERAL HRS /NOTHING LIKE THE
EARLIER ACTIVITY/. THIS EARLIER ACTIVITY WAS A BATCH OF SCATTERED
SHOWERS W/ EMBEDDED SMALL ICE PELLETS/GRAUPEL AS CAN OCCUR W/ SUCH A
DEEP AND STRONG UPPER VORT LOBE SLIDING DOWN FROM THE NW.
ONE LAST UPPER VORT WILL SLIDE DOWN CNTRL PA IN THE COMING HRS
TOWARD NERD MD...GRADUALLY WEAKENING INTO THE MAIN UPPER LOW AND THE
SYSTEM AS A WHOLE WILL ROTATE OFF THE NEW ENGLAND COASTLINE INTO SRN
NOVA SCOTIA OVERNIGHT. THE LINGERING EFFECTS OF THE SYSTEM AS IT
EXITS WILL BE BREEZY CONDITIONS WELL INTO THE LATE NIGHT HRS...ON
INTO SAT AFTN.
LOWS WILL DROP INTO THE 30S OVERNIGHT...BELOW FREEZING ACROSS MUCH
OF THE WRN HALF OF THE CWA AND M-U30S FOR THE PIEDMONT-COASTAL
AREAS. DRY-DOWNSLOPING WINDS WILL BEEN PERSISTENT TODAY...AND WILL
CONTINUE THRU TOMORROW. WITH THE LOWER HUMIDITIES...TEMPS WILL BE
ALLOWED TO DROP SEVERAL DEGREES FROM LAST NIGHT/S LOWS.
&&
.SHORT TERM /SATURDAY/...
OUTSIDE OF ANOTHER BREEZY DAY /THO A TOUCH LESS THAN TODAY/ A FAIRLY
QUIET DAY. THE UPSLOPE SNOW WILL DISSIPATE TO FLURRIES INTO THE
PRE-DAWN HRS AND END BY LATE MRNG. SKIES WILL GENERALLY CLEAR
THROUGHOUT THE DAY...THO TEMPS ONLY EXPECTED TO WARM-UP A COUPLE OF
DEGREES FROM TODAY/S MAXIMA. BROAD SFC HIGH WILL SET-UP OVER THE
DEEP SOUTH...W/ THE NRN EDGE OF THE HIGH SPILLING INTO THE MID ATLC
ON SAT. THE GUSTY WILL STILL MAKE CONDITIONS FEEL MUCH COLDER THAN
THE AMBIENT TEMP TOMORROW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WEAKENS OVER THE AREA SUNDAY...ALLOWING A COLD FRONT
TO APPROACH/MOVE THROUGH FROM THE WEST MONDAY. HAVE INCREASED POPS
TO LIKELY ACROSS THE AREA BY MONDAY AFTERNOON...REDUCING DURING THE
EVENING.
LIGHT UPSLOPE PRECIP MAY OCCUR OVERNIGHT MONDAY INTO EARLY
TUESDAY...OTHERWISE HIGH PRESSURE RETURNS TUESDAY/TUESDAY NIGHT
BEFORE MOVING OFF THE COAST WEDNESDAY.
MODELS INDICATE LOW PRESSURE NEAR THE GULF COAST WEDNESDAY MOVING
NORTHEAST WEDNESDAY NIGHT INTO THURSDAY. GFS IS OFF THE COAST WHILE
THE ECMWF IS INLAND. SO TRACK AND ALSO TIMING DIFFERENCES WILL NEED
TO BE RESOLVED IN FUTURE FORECASTS...BUT IT LOOKS AS IF SUCH A
SYSTEM WILL HAVE SOME IMPACT ON THE CWA WITH SOME RAIN DURING THE
MID WEEK TIME FRAME. THIS MAY BE FOLLOWED BY UPSLOPE PRECIP LATE IN
THE WEEK AS AN UPPER TROUGH MAY CONTINUE TO INFLUENCE THE REGION.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
GUSTY WINDS /20-30KT/ STILL THE STORY FOR AREA TAF SITES. PEAK WIND
GUSTS FOR THE METRO AREAS WILL KEEP COMING IN FOR THE NEXT SEVERAL
HRS...W/ A SLIGHT DECREASE AFTER SUNSET. THE AREA WILL STILL BE
UNDER AN ACTIVE PORTION OF AN EXITING UPPER LOW PRESSURE AREA...SO
WINDS AT THE SFC AND THRU THE LOWEST FEW THOU FT WILL STILL GUST
INTO THE 20-30KT RANGE THRU LATE TONIGHT AND 15-25KT FOR THE DAYTIME
HRS ON SAT.
HIGH PRESSURE GIVES WAY TO AN APPROACHING COLD FRONT ON MONDAY THAT
MAY PRODUCE MVFR SHOWERS. WINDS SHIFT BEHIND THE FRONT MONDAY. HIGH
PRESSURE RETURNS TUESDAY.
&&
.MARINE...
GALE CONDITIONS EXPECTED IN INTERMITTENT BURSTS OVER ALL THE CWA
WATERS /BAY-TP/ WELL INTO THE LATE NIGHT HRS. ADDED THE 2 WRN TP
ZONES AS CONSISTENT SHOWER ACTIVITY HAS BROUGHT STEADY +30KT GUSTS
TO THE AREA THRU THE LAST FEW HRS. AS THE LAST ROUND OF UPPER ENERGY
SLIDES DOWN THRU THE REGION...WINDS WILL REMAIN BREEZY INTO THE
OVERNIGHT HRS...TAPERING OFF A BIT INTO THE PRE-DAWN HRS SAT BUT
PICKING BACK UP INTO SOLID SCA CONDITIONS FOR THE DAYTIME HRS SAT.
HIGH PRESSURE WEAKENS SUNDAY AND IS FOLLOWED BY A COLD FRONTAL
PASSAGE MONDAY. SMALL CRAFT ADVISORY WINDS MAY SETTLED IN BEHIND THE
FRONT MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE RETURNS BRIEFLY
TUESDAY NIGHT INTO WEDNESDAY AHEAD OF THE NEXT SYSTEM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR VAZ021.
WV...WINTER WEATHER ADVISORY UNTIL 2 AM EST SATURDAY FOR WVZ054-501-
503.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR
ANZ530>533-535>542.
GALE WARNING UNTIL 6 AM EST SATURDAY FOR ANZ530>543.
SMALL CRAFT ADVISORY FROM 6 AM TO 9 PM EST SATURDAY FOR ANZ534-
543.
&&
$$
SYNOPSIS...GMS/PELOQUIN
NEAR TERM...GMS
SHORT TERM...GMS
LONG TERM...PELOQUIN
AVIATION...GMS/PELOQUIN
MARINE...GMS/PELOQUIN