Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 300300
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1000 PM EST THU JAN 29 2015

.SYNOPSIS...
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT. HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING WINDY AND COLD CONDITIONS
FRIDAY AND FRIDAY NIGHT. THE HIGH WILL BUILD OVER THE AREA
SATURDAY...BUT LOW PRESSURE MAY IMPACT THE AREA LATER SUNDAY INTO
MONDAY. COLD HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF
NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST OF THE PRECIP HAS MOVED OUT OF THE CWA...AND THUS THE LARGE
PORTION OF THE ADVISORIES HAVE BEEN CANCELLED.

THERE ARE A COUPLE OF EXCEPTIONS. HAVE EXTENDED WINTER WEATHER
ADVISORIES FOR PORTIONS OF NORTHERN MARYLAND AND THE EASTERN WEST
VIRGINIA PANHANDLE /EAST OF THE ALLEGHENY FRONT/ UNTIL 1 AM AS A
VORT MAX WILL LIKELY BRING SOME ADDITIONAL LATE EVENING PRECIP
JUST SOUTH OF THE MASON DIXON LINE. EXPECT P-TYPE TO EVENTUALLY
TRANSITION TO SNOW...BUT INITIALLY THERE COULD BE SOME FREEZING
RAIN OR FREEZING DRIZZLE IN THOSE AREAS THAT ARE BELOW FREEZING AT
THE SURFACE. RUC FOR EXAMPLE SHOWS A BRIEF PERIOD OF -ZR AT HGR/MRB
LATE THIS EVENING. WILL HAVE TO WATCH FURTHER EAST TOWARD
BALTIMORE...BUT BY THE TIME THIS NEXT ROUND OF PRECIP WOULD GET
THERE THINK P-TYPE WOULD BE JUST SNOW AND LITTLE ACCUMULATION IS
EXPECTED THUS NO ADVISORY EXTENSION THAT FAR EAST.

WINTER WEATHER ADVISORIES ALSO CONTINUE ON THE WESTERN SLOPES OF
THE POTOMAC HIGHLANDS AS PRECIPITATION WILL TRANSITION TO SNOW AND
SNOW COULD BE HEAVY AT TIMES LATE TONIGHT INTO FRIDAY MORNING.

SYNOPTICALLY...AS WAS MENTIONED EARLIER A VORT MAX ASSOCIATED WITH
AN UPPER TROUGH WILL MOVE THROUGH TONIGHT AND WILL BE ACCOMPANIED
BY A COLD FRONTAL PASSAGE. FROPA WILL INITIATE A WIND SHIFT TO THE
NORTHWEST. NORTHWEST WINDS WILL BEGIN TO BECOME GUSTY OVER THE
POTOMAC HIGHLANDS LATE TONIGHT. RE-POPULATED WINDS USING THE NAM
AND WINDS REMAIN BELOW WIND ADVISORY CRITERIA THROUGH
TONIGHT...BUT ARE EXPECTED TO REACH CRITERIA DURING THE DAY
FRIDAY /SEE SHORT TERM/.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
HAVE ISSUED A WIND ADVISORY FOR MUCH OF THE CWA EXCEPT FOR THE
CENTRAL VA FOOTHILLS AREA. BUFKIT POINT FORECAST SOUNDINGS FROM NAM
AND GFS SUGGEST AOA 40 KT ABLE TO MIX DOWN TO THE SURFACE
PARTICULARLY IN THE AFTERNOON AND EVENING HOURS. WBCNPWLWX HAS
ALREADY BEEN ISSUED. STRONG VORT MAY ALSO PRODUCE SCATTERED SNOW
SHOWERS WHICH ARE REFLECTED IN THE FORECAST.

PREV...

HIGH PRES BLDG INTO THE MID ATLC WL LEAD TO A STRNG PRES GRAD
ACROSS THE AREA. THIS IN TURN WL LEAD TO A WINDY DAY. BUFKIT
X-SXNS ARE SHOWING INXS OF 40 KT A FEW THOUSAND FT OFF THE GRND.
THIS WL HV THE PTNL TO BE BROUGHT TO THE SFC. WE ARE ADVSRTSG THE
PSBLTY OF A WIND ADVSRY - MOST LKLY AREAS WL BE ABV 1500 FT AND
ACROSS THE NRN 1/2 OF THE FCST AREA.

HIGHS IN THE LM30S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
HIGH PRES BLDG OVR THE RNG FRI NGT WL LEAD TO CHILLY TEMPS. LOWS
IN THE TEENS ACROSS MUCH OF THE AREA. WINDS WL BE DIMINISHING
OVRNGT...BUT W/ COLD TEMPS WINDS CHILLS XPCTD TO BE IN THE SINGLE
DIGITS E OF THE MTNS. PRSNTLY SEEING VALUES AS LOW AS -14 IN THE
HIGHLANDS. IF THIS TREND CONTS A WIND CHILL ADVSRY WL BE NEEDED
FOR OUR FAR WRN AREA.

SAT LOOKS TO BE M SUNNY BUT COLD W/ HIGHS RANGING FM THE U20S TO
THE MU30S OVR MOST OF THE AREA.

SAT NGT WL BE COLD...BUT A LTL WARMER THAN FRI NGT. NO WINDS SO
WIND CHILL WL NOT BE A CONCERN.

WHAT HAD BEEN A SPLIT IN THE MODELS BETWEEN A LOW TRACK TO OUR NORTH
AND ANOTHER TRACK TO OUR SOUTH SEEMS TO BE CONSOLIDATING AROUND THE
SOUTHERN TRACK NOW...TAKING IT EAST THRU S VA OR NC. THAT SUPPORTS
SNOW FOR MUCH IF NOT ALL OF OUR REGION. WOULD BE PASSING THRU AT A
GOOD CLIP BUT ACCUMULATING SNOW CERTAINLY A POSSIBILITY FOR SUN
AFTERNOON INTO MONDAY MORNING.

HIGH PRESSURE WILL FOLLOW FOR TUE. NEXT COLD FRONT POISED FOR
WEDNESDAY.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
CAN/T RULE OUT BRIEF LIGHT SNOW OR FREEZING DRIZZLE AT MRB
TONIGHT...OTHERWISE REST OF THE TERMINALS LOOK DRY WITH VFR CLOUD
DECK AROUND 5K FT. COLD FRONT MOVES THROUGH AFTER MIDNIGHT. THIS
WILL ALLOW FOR A WIND SHIFT SPREADING EAST THROUGH THE TERMINALS.
WINDS WILL BE VERY GUSTY DURING THE DAY ON FRIDAY...POSSIBLY AOA
40 KT FROM AFTERNOON INTO EVENING. WILL ALSO HAVE TO WATCH FOR
AFTERNOON SNOW SHOWERS AND FLURRIES BUT CONFIDENCE TOO LOW TO
MENTION IN TAF ATTM.

WINDY CONDS FRI AND FRI NGT AS HIGH PRES BLDS INTO THE AREA. NO
PROBS XPCTD AVIATION-WISE SAT OR SAT NGT.

SNOW AND IFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON INTO MONDAY
MORNING AS LOW PRESSURE SLIDES BY TO OUR SOUTH. VFR FOR TUESDAY.

&&

.MARINE...
SCA CONDITIONS CONTINUE UP THE BAY TONIGHT DUE TO S/SE WINDS. WIND
SHIFT OCCURS WITH A COLD FRONTAL PASSAGE LATE TONIGHT...AND GALES
ARE EXPECTED ON FRIDAY LASTING INTO FRIDAY NIGHT.

A GALE WRNG IS IN EFFECT FM FRI MRNG THRU THE ERLY HRS OF SAT
MRNG..AND THEN AN SCA WL LKLY GO INTO EFFECT AFTRWARDS FOR THE
RMNDR OF THE NGT. WINDS WL BE DIMINISHING FOR SAT AND SAT NGT.

GUSTY WINDS AND A SMALL CRAFT ADVISORY ARE POSSIBLE ON MONDAY INTO
MONDAY NIGHT AS LOW PRESSURE INTENSIFIES OFFSHORE.

&&

.TIDES/COASTAL FLOODING...
ANOMALIES HAVE INCREASED TO AROUND 1.5 FT ON THE WESTERN SHORE OF
THE CHESAPEAKE BAY...CLOSER TO 1 FT ON THE UPPER TIDAL POTOMAC
RIVER. HOWEVER DUE TO THE RELATIVELY LOW ASTRONOMICAL
TIDES...THESE ANOMALIES ARE NOT EXPECTED TO RESULT IN MINOR TIDAL
FLOODING OVERNIGHT. IN ADDITION...WINDS SHIFT TO THE NORTHWEST
LATE TONIGHT INTO FRIDAY MORNING AND ANOMALIES SHOULD BEGIN TO
DECREASE.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WIND ADVISORY FROM NOON FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR DCZ001.
MD...WIND ADVISORY FROM 10 AM FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR MDZ003-501-502.
     WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR MDZ003>005-
     502.
     WIND ADVISORY FROM NOON FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR MDZ004>006-011-013-014-016>018-503>508.
     WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MDZ501.
VA...WIND ADVISORY FROM 10 AM FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR VAZ025>031-503-504-507-508.
     WIND ADVISORY FROM NOON FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR VAZ040-051>055-057-501-502-505-506.
     WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR VAZ503.
WV...WIND ADVISORY FROM 10 AM FRIDAY TO MIDNIGHT EST FRIDAY NIGHT
     FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR WVZ051>053.
     WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR WVZ501-503-
     505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
     537>543.
     GALE WARNING FROM 6 AM FRIDAY TO 1 AM EST SATURDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BPP
NEAR TERM...BPP
SHORT TERM...ABW
LONG TERM...CAS
AVIATION...BPP/CAS/ABW
MARINE...BPP/CAS/ABW
TIDES/COASTAL FLOODING...







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