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000
FXUS61 KPHI 301758
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1258 PM EST FRI JAN 30 2015

.SYNOPSIS...
WINDY AND PROGRESSIVELY COLDER CONDITIONS ARE MOVING OVER THE AREA
BEHIND A COLD FRONT THAT MOVED THROUGH THIS MORNING. HIGH
PRESSURE WILL BUILD ACROSS THE AREA FOR TONIGHT THROUGH EARLY
SUNDAY. A LOW PRESSURE SYSTEM WILL AFFECT THE AREA SUNDAY NIGHT
THROUGH MONDAY. ANOTHER HIGH WILL MOVE IN FOR TUESDAY AND
WEDNESDAY. A COASTAL DISTURBANCE MAY AFFECT THE AREA NEXT
THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT HAS MOVED THROUGH MOST OF THE AREA. TEMPERATURES
ARE HOLDING STEADY, BUT WILL BEGIN TO DROP LATER THIS
AFTERNOON. STRONG NORTHWEST WINDS WILL CONTINUE, WITH GUSTS OVER
40 MPH POSSIBLE AT TIMES. SOME RESIDUAL SNOW SHOWER
ACTIVITY...ESPECIALLY OVER THE NORTH...WITH SUBSIDE AS THE
AFTERNOON WEARS ON. SKIES WILL REMAIN CLOUDY.
&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
LOW PRESSURE WILL RAPIDLY DEEPENS OFF THE NEW ENGLAND COAST THIS
EVENING. MEANWHILE, HIGH PRESSURE OVER THE MIDWEST WILL BUILD
EASTWARD. A TIGHTENING PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS
WILL PRODUCE WINDY CONDITIONS ACROSS THE MID ATLANTIC. AS MENTIONED
IN THE NEAR TERM, A WINDY ADVISORY WAS ISSUED FOR THE ENTIRE AREA
AND GOES THROUGH TONIGHT. MOMENTUM TRANSFER ALGORITHMS ON GFS BUFKIT
SOUNDINGS SUPPORT MIXING OF 40 KT WINDS DOWN TO THE SURFACE WHILE THE
WIND PROFILE FROM THE NAM ARE SLIGHTLY WEAKER. VERY STEEP LAPSE
RATES WILL BE PRESENT IN THE BOUNDARY LAYER UNDER STRONG CAA AS THE
ARCTIC AIRMASS MOVES IN. THE DEEPER MIXING ADVERTISED BY THE GFS AND
SEVERAL SREF MEMBERS WAS FAVORED IN THIS SETUP, WHICH SUPPORTED A
WIND ADVISORY.

LOW TEMPS TONIGHT RANGE FROM NEAR ZERO IN THE POCONOS TO MID TEENS
IN THE DELMARVA. COMBINED WITH THE WINDS, WIND CHILLS ARE FORECAST
TO BE AT OR BELOW ZERO ACROSS JUST ABOUT THE ENTIRE AREA BY EARLY
SATURDAY MORNING. THE WIND CHILL ADVISORY THAT WAS ALREADY IN EFFECT
FOR THE POCONOS WAS EXPANDED TO SUSSEX COUNTY, NJ FOR WIND CHILL
VALUES OF -10F TO -20F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
SATURDAY THRU SUNDAY AFTERNOON...
HIGH PRESSURE TO THE WEST WILL CONTINUE TO USHER COLD AND WINDY
CONDITIONS SATURDAY WITH TEMPERATURES SOME 20 DEGREES BELOW NORMAL.
WIND ADVISORIES WILL BE IN EFFECT FOR THE CWA FOR THE MORNING
SATURDAY. WINDS WILL SUBSIDE BY LATE IN THE DAY SAT AS THE HIGH
CRESTS OVER THE AREA. DRY WEATHER IS FORECAST THROUGH SUNDAY
MORNING. SKY COVER...PARTLY TO MOSTLY SUNNY SAT AND MOSTLY CLOUDY
SKIES SUNDAY.

SUNDAY EVENING THROUGH MONDAY...
THE NEXT SIGNIFICANT WEATHER PRODUCER FOR OUR AREA WILL ARRIVE FROM
THE OHIO VALLEY SUNDAY AND THE CENTER OF THE LOW WILL MOVE ACROSS
THE DELMARVA MONDAY MORNING. THE MOST RECENT MODELS ARE OFFERING A
MORE NORTHWARD TREND WITH THE SYSTEM WHEN COMPARED TO THU`S MODEL
RUNS. CLOUDS WILL THICKEN SUNDAY AND SNOW WILL ARRIVE OVER THE
DELMARVA AND SE PA LATE IN THE AFTERNOON. THE PRECIPITATION WILL
OVERSPREAD THE WHOLE AREA SUNDAY NIGHT AND CONTINUE INTO MONDAY.
WHILE SNOW WILL BE THE PREDOMINANT P-TYPE...SOME SLEET WILL OCCUR
OVER THE DELMARVA AND SRN NJ LATER SUN NIGHT AND INTO MONDAY.
PRELIMINARY SNOWFALL ACCUMS LOOK TO BE 4 TO 5 INCHES ACROSS THE SE
PA BERKS COUNTY--LEHIGH VALLEY--NRN NJ  REGION WITH LIGHTER AMOUNTS
BOTH NORTH AND SOUTH.  SLEET AND RAIN (FAR SOUTH DEL) WILL REDUCE
THE ACCUMS OVER THE DELMARVA AND SRN NJ AREAS. IF THE TRACK
CONTINUES A NORTHWARD TREND...THEN MORE RAIN WILL MIX IN OVER THE
SRN FORECAST AREA. THE PRECIP WILL END AS SNOW ONCE THE LOW SWEEPS
BY MONDAY AFTERNOON BRINGING IN COLDER AIR BEHIND IT. HWO PRODUCT
WILL HIGHLIGHT THE POTENTIAL FOR A SUNDAY NIGHT/MONDAY WINTRY
WEATHER EVENT. FUTURE FCSTS WILL OFFER BETTER SNOWFALL FCST AND
POSSIBLE HEADLINES...SO CHECK BACK LATER TODAY AND SAT/SUN FOR
UPDATES.

MONDAY NIGHT THRU WEDNESDAY...
ANOTHER HIGH PRESSURE SYSTEM WITH COLD AIR WILL AFFECT THE AREA.
HIGH TEMPERATURES TUE WILL BE IN THE TEENS AND LOW 20S...SO READINGS
AGAIN WILL BE 15 TO 20 DEGREES BELOW NORMAL. MORE WIND CHILL
HEADLINES POSSIBLE ACROSS THE FAR NORTH. MODERATING TEMPS WED WITH
HIGHS IN THE UPPER 20S TO MID 30S OVER THE REGION.

WEDNESDAY NIGHT THRU THURSDAY...
THE 00Z GFS AND OLDER 12Z EC MODELS BOTH SHOW ANOTHER H5 TROUGH
SWINGING ACROSS THE GREAT LAKES WITH A SFC LOW PRESSURE DEVELOPING
AHEAD OF IT. BOTH OF THESE MODELS ALSO SHOW THE LOW PRESSURE SYSTEM
DEVELOPING ACROSS THE DEEP SOUTH AND MOVING UP THE EAST COAST. THE
LATEST 00Z EC SHOWED THE LOW ALSO...BUT PUSHED IT OFFSHORE THU NGT
INTO FRIDAY WITH HIGHER QPF ONLY NEAR THE COAST. WE HAVE GONE ALONG
WITH THE WPC AND RAISED POPS UP A BIT FOR THESE PERIODS. THEY ARE
STILL ONLY IN THE CHC RANGE HOWEVER.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

EXPECT MVFR CEILINGS BETWEEN 2000 AND 4000 FEET AT MANY TAF SITES
THIS AFTERNOON...THEN IMPROVING THIS EVENING AS SKIES CLEAR. THE
BIG ISSUE WILL BE THE STRONG NORTHWEST WINDS, GUSTING BETWEEN 30
AND 40 KT AT TIMES. THESE WINDS WILL CONTINUE THROUGH MOST OF
SATURDAY BEFORE SUBSIDING LATE SATURDAY AFTERNOON.

OUTLOOK...
SATURDAY...VFR WITH WINDY CONDITIONS.
SATURDAY NIGHT THRU SUN AFTERNOON...VFR. INCREASING CLOUDS SUNDAY.
SUN NIGHT THRU MONDAY...WIDESPREAD IFR/LIFR. SNOW AND MIXED
PRECIP. ACCUMULATING SNOW AT PHL.
MONDAY NIGHT THRU TUE...IMPROVING CONDITION MON EVE. VFR MON NGT
HRU TUE.

&&

.MARINE...
NO CHANGES TO THE MARINE HEADLINES. GALE WARNING CONTINUE. EXPECT GUSTS
IN THE 35-40 KT LATE THIS AFTERNOON INTO TONIGHT. SEAS WILL ALSO
BUILD TO 5-8 FT BY TONIGHT.

OUTLOOK...
SAT AND SAT NIGHT...GALES DIMINISH SAT. SCA CONDITIONS EARLY SAT NIGHT.
SUN AND SUN NIGHT...SUB-SCA CONDITIONS. SNOW AND SLEET LATE SUN NIGHT.
MON AND MON NIGHT...SCA CONDITIONS EXPECTED.
TUE...SCA SEAS ON THE OCEAN EARLY THEN SUB-SCA CONDITIONS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST SATURDAY
     FOR PAZ054-055-060>062-070-071-101>106.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
     SATURDAY FOR PAZ054-055.
NJ...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST SATURDAY
     FOR NJZ001-007>010-012>027.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
     SATURDAY FOR NJZ001.
DE...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST SATURDAY
     FOR DEZ001>004.
MD...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST SATURDAY
     FOR MDZ008-012-015-019-020.
MARINE...FREEZING SPRAY ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST
     SATURDAY FOR ANZ430-431-450>455.
     GALE WARNING UNTIL 6 PM EST SATURDAY FOR ANZ430-431-450>455.

&&

$$
SYNOPSIS...O`HARA/MIKETTA
NEAR TERM...MIKETTA
SHORT TERM...KLEIN/MIKETTA
LONG TERM...O`HARA
AVIATION...KLEIN/MIKETTA/O`HARA
MARINE...KLEIN/MIKETTA/O`HARA