Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 251950
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
250 PM EST THU DEC 25 2014

.SYNOPSIS...
MILD SOUTHERN HIGH PRESSURE WILL BUILD THROUGH FRIDAY...BEFORE
MOVING OFFSHORE ON SATURDAY. A WEAK COLD FRONT WILL PUSH IN FROM
THE NORTHWEST SUNDAY. THEN LOW PRESSURE FROM THE DEEP SOUTH WILL
RIDE UP ALONG THAT FRONT AND PASS JUST SOUTH OF US MONDAY. COLDER
HIGH PRESSURE WILL FOLLOW FOR MID WEEK.
&&

.NEAR TERM /THROUGH FRIDAY/...
HIPRES CENTERED OVER TN WL BE ADVCG TWD CWFA TAFTN-TNGT...AND WL BE
OVHD FRI. THERES A BIT OF A P-GRAD ACRS MD/VA...BUT WINDS HV BEEN IN
THE MEAN MIXED LVL...ARND 25 KT. ALSO HV HAD BKN CLDS IN THERMAL
TROF. AS SUBSIDENCE INCREASES LT TDA INTO TNGT...BOTH OF THESE WL
DECR.

DEWPTS BACK IN NERN KY IN THE LWR 30S ATTM. THATS A HINT OF WHERE
RADL COOLING WL TAKE OUR TEMPS TNGT. MOS CONCURS. SINCE SOURCE RGN
CONTINENTAL...WENT MUCH CLOSER TO MAV MAXT TMRW.
&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
TEMPS OVERNIGHT WILL ONLY TOUCH THE FREEZING MARK ACROSS THE
SHELTERED VLYS/LOW LANDS OVER THE PIEDMONT/SHEN VLY. HIGHER TERRAIN
WILL ACTUALLY HAVE THE WARMEST VALUES IN THE AREA W/ THE ELEVATED
INVERSION. CLEAR/CALM CONDITIONS EVEN AS A WEAK UPPER TROUGH PASSES
OVERHEAD AND WEAKENS AS IT APPROACHES THE COAST - A PRECURSOR THE
NEXT UPPER WAVE.

MUCH OF SATURDAY WILL REMAIN CLEAR AND QUIET...W/ ONLY A FEW PASSING
CLOUDS AND RELATIVELY WARM CONDITIONS. THE CENTER OF THE HIGH WILL
BE DRIFTING OFF THE CAROLINA COAST AND ALLOW FOR TEMPS TO REACH THE
M-U50S ACROSS MUCH OF THE REGION. OUR BRIEF REPRIEVE FROM ACTIVE WX
WILL BE INTERRUPTED BY LATE SAT NIGHT...AS THE BEGINNINGS OF THE
NEXT WAVE OF LOW PRESSURE ARRIVE IN THE FORM OF DENSE MID-UPPER
LEVEL CLOUDS. THE ONSLAUGHT OF DENSE CLOUD COVER WILL PREVENT TEMPS
FROM DROPPING BACK TOWARD THE FREEZING MARK...UNLIKE THE PREVIOUS
COUPLE OF NIGHTS. THIS WILL ALSO BE KEY IN MITIGATING THE POTENTIAL
FOR FROZEN PRECIP OVER THE REGION DURING THE INITIAL STAGES OF THE
INCOMING SYSTEM.
&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL PUSH ACROSS THE REGION SUNDAY BEFORE SLIDING INTO
THE CAROLINAS SUNDAY NIGHT. SOME STRATIFORM RAIN WILL ACCOMPANY THE
FRONT SUNDAY THROUGH MONDAY. SOME LIGHT SNOW COULD MIX WITH A LITTLE
RAIN IN THE POTOMAC HIGHLANDS AND ALONG PORTIONS OF THE MASON-DIXON
LINE SUNDAY NIGHT AS COLDER AIR IS EXPECTED TO PUSH INTO THESE AREAS
FIRST. WE`LL HANG ONTO A SLIGHT CHANCE OF SOME LIGHT RAIN OR SNOW
MONDAY NIGHT...MAINLY ACROSS THE SOUTH...AS THERE IS STILL SOME
DEGREE OF UNCERTAINTY OF A LOW DEVELOPING ALONG THE FRONT TO THE
SOUTH. THE 00Z EURO TRIES TO FORM A LOW ALONG THE NORTH AND SOUTH
CAROLINA BORDER. THE LATEST 12Z GFS WANTS TO FORM A LOW 12 HOURS
EARLIER AND ALONG THE VIRGINIA AND NORTH CAROLINA BORDER BEFORE
QUICKLY KICKING THE LOW OUT TO SEA.

HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT AND
TUESDAY...THUS PERSISTING WEDNESDAY AND THURSDAY. DRIER AND COOLER
AIR WILL MOVE INTO THE REGION...ESCORTED BY THE HIGH.
&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR THRU VALID TAF PD. WLY WNDS G25KT TAFTN...RAPIDLY DECRSG TNGT
AFTR SUNSET. SHUD HV LTL WND BY MIDNGT...CONTG INTO FRI. WHEN WINDS
DO PICK UP AGN...ITLL BE MIDDAY AND THE DIRECTION WL BE SLY. BKN
CLDS /CIGS 050-060/ WL ALSO BE DSPTG BY SUNSET.

HIGH PRESSURE REMAINS OVERHEAD FOR LATE FRI INTO MUCH OF SAT...W/
CALM WINDS AND SOLID VFR CONDS.

MVFR TO IFR CONDITIONS MAY OCCUR WITH LIGHT RAIN SUNDAY INTO SUNDAY
NIGHT. WINDS SOUTHWEST SHIFTING NORTH 5 TO 10 KNOTS WITH FRONTAL
PASSAGE.

MVFR CONDITIONS POSSIBLE MONDAY WITH LINGERING LIGHT RAIN. WINDS
NORTHEAST 5 TO 10 KNOTS.
&&

.MARINE...
FOR THE MOST PART...WINDS HV STUCK IN SCA LVL AS ANTICIPATED. TPLM2
WAS THE EXCEPTION...BRIEFLY VENTURING INTO GLW. HIPRES BLDG ACRS
WATERS FOR THE REST OF THE AFTN INTO TNGT. WNDS WL BE DECRSG FM
HERE...DROPPING BLO SCA BY ELY EVNG...AND LESS THAN 10 KT OVNGT.
WNDS WL BECOME SLY FRI...STILL ARND 10 KT.

LIGHT WINDS OVER THE WATERS TO END THE WEEK W/ ONLY SOME MINOR SLY
CHANNELING SAT NIGHT AS A SFC HIGH MOVES OFF THE CAROLINA COAST.

&&

.TIDES/COASTAL FLOODING...
TIDAL DEPARTURES DROPPING TO LESS THAN A FOOT...AND WILL CONTINUE TO
DECLINE IN WLY WINDS. NO ADDTL ISSUES ANTICIPATED ATTM.
&&

.EQUIPMENT...
KLWX 88D WILL REMAIN OUT OF SERVICE UNTIL SATURDAY...WHEN PARTS TO
REPAIR WILL ARRIVE.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>534-537>543.
     SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ535-
     536.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...GMS
LONG TERM...KLW
AVIATION...HTS/GMS/KLW
MARINE...HTS/GMS
TIDES/COASTAL FLOODING...HTS
EQUIPMENT...HTS







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