-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPHI 051728
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1228 PM EST THU DEC 5 2013

.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT NORTH OF THE AREA TODAY. A FRONTAL
BOUNDARY IS EXPECTED TO MOVE ACROSS TH EAST COAST THURSDAY NIGHT
INTO FRIDAY MORNING AND MOVE TO OUR SOUTH OVER THE WEEKEND. HIGH
PRESSURE WILL BRIEFLY BUILD ACROSS THE NORTHEAST SATURDAY NIGHT INTO
SUNDAY. AN AREA OF LOW PRESSURE WILL DEVELOP ACROSS THE LOWER
MISSISSIPPI RIVER VALLEY, THEN STRENGTHEN AS IT MOVES NORTHWARD INTO
THE GREAT LAKES SUNDAY NIGHT. THIS WILL LIFT ANOTHER FRONTAL SYSTEM
ACROSS OUR REGION MONDAY. A COUPLE OF WEAK CLIPPER SYSTEMS MAY SKIRT
ACROSS THE NORTHERN TIER OF THE COUNTRY NEXT WEEK BEFORE HIGH
PRESSURE BUILDS ACROSS THE REGION LATE IN THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
NOT MUCH TO CHANGE WITH THE LATEST UPDATE TO THE FORECAST. THE
MAIN CHANGE WAS TO SLOW DOWN THE ONSET OF PRECIPITATION. THERE IS
A SWATH OF RAIN TO THE WEST OF THE AREA AND IT WILL GRADUALLY PUSH
EASTWARD THROUGH THIS AFTERNOON. IT STILL LOOKS TO BE OVER AN HOUR
AWAY AND WE HAVE MADE ADJUSTMENTS TO THE POPS THROUGH THIS
EVENING.

TEMPERATURES ARE GENERALLY IN THE 50S ACROSS THE REGION AND WILL
CONTINUE TO WARM IN THE SOUTHERLY FLOW, ESPECIALLY IN THE AREAS TO
THE SOUTH OF A WARM FRONT THAT IS DRAPED ACROSS OUR AREA.

LOW PRESSURE WILL BE MOVING ACROSS THE UPPER GREAT LAKES AND ONTARIO
CANADA TODAY. THE ATTACHED WARM FRONT WILL BE CROSSING THROUGH THE
AREA THROUGH THIS AFTERNOON. AREAS TO THE FAR NORTH MAY REMAIN IN
THE FRONTAL ZONE INTO THE AFTERNOON WITH A CONTINUATION OF LOWER
CLOUDS AND DRIZZLE/LIGHT RAIN THERE. TEMPERATURES TODAY WILL BE
WELL ABOVE NORMAL WITH LOW/MID 60S CENTRAL/SOUTH AND MID TO UPPER
50S NORTH.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY TONIGHT. A COLD
FRONT WILL MOVE INTO THE WRN AREAS AFTER MIDNIGHT AND CROSS THROUGH
THE REST OF THE REGION BY AROUND DAWN. MOSTLY LIKELY OR CATEGORICAL
POPS FOR SHOWERS WILL BE ACROSS THE AREA. POPS ACROSS THE SRN
DELMARVA WILL REMAIN IN THE CHC RANGE FOR NOW. IT WILL REMAIN MILD
OVERNIGHT BEFORE TEMPERATURES DROP BEHIND THE FRONT. THE COLDER AIR
WILL ARRIVE ACROSS THE WRN AREAS BY DAWN BEFORE SPREADING EAST.
WINDS WILL SHIFT FROM SW TO NW BEHIND THE FRONT. OVERALL PRECIP THRU
12Z SAT WILL TOTAL .10 ACROSS THE DEL VALLEY AND CLOSER TO .50 IN
THE SRN POCONOS.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AN ACTIVE WEATHER PATTERN FOR A GOOD PORTION OF THE LONG TERM
FORECAST WITH A BREAK POSSIBLE TOWARD THE END.

THE BEGINNING OF THE LONG TERM PERIOD STARTS OFF WITH A FRONTAL
BOUNDARY THAT WILL BE MOVING OFF THE EAST COAST EARLY FRIDAY
MORNING. THE FRONT WILL SLOWLY PUSH OFFSHORE, BUT THERE WILL STILL
REMAIN QUITE A BIT OF MOISTURE LAGGING BEHIND THE FRONT AS SOUTH
WEST FLOW ALOFT WILL KEEP A GOOD MOISTURE INFLUX ACROSS THE AREA.
THERE MAY BE A BRIEF BREAK IN PRECIPITATION FRIDAY MORNING AS ONE
SHORT WAVE/VORTICITY IMPULSE SLIDES TO OUR NORTH, BEFORE ANOTHER
ROUND OF PRECIPITATION BEGINS LATER DURING THE DAY INTO FRIDAY
NIGHT AS A SECOND SHORT WAVE/VORTICITY IMPULSE APPROACHES AND
PASSES THROUGH THE AREA. PRECIPITATION WILL LIKELY START OUT AS RAIN
AS TEMPERATURES WILL BE FAIRLY WARM EARLY IN THE DAY, BEFORE
CHANGING OVER TO A WINTRY MIX BY FRIDAY EVENING AND OVERNIGHT. IN
FACT, THE HIGH TEMPERATURES WILL LIKELY OCCUR EARLY IN THE DAY AS
TEMPERATURES ARE EXPECTED TO DROP DURING THE DAY. THERE SHOULD BE
ENOUGH OF A COLD SURGE BEHIND THE FRONT TO ALLOW ALL PRECIPITATION
TO CHANGE OVER TO A RAIN/SLEET OR SNOW/SLEET MIXTURE. THERE IS THE
POSSIBILITY FOR SOME FREEZING RAIN TO OCCUR, MAINLY FOR OUR FAR
NORTHWESTERN ZONES.

SATURDAY INTO SATURDAY NIGHT MAY END UP BEING DRY FOR MOST AREAS AS
THE FRONT WILL HAVE PUSHED TO OUR SOUTH AND HIGH PRESSURE BEGINS TO
BRIEFLY BUILD TO OUR NORTH. DRIER AIR IS EXPECTED TO BUILD ACROSS
THE AREA AND THERE WILL NOT BE MUCH OF ANY VORTICITY IMPULSES TO
HELP CREATE ANY SHOWER ACTIVITY. THE ONLY EXCEPTION IS OUR SOUTHERN
AREAS WHERE THERE MAY BE SOME SHOWERS EARLY SATURDAY MORNING AS THE
LAST OF THE PRECIPITATION PUSHES SOUTHWARD.

THE HIGH PRESSURE LIFTS INTO THE NORTHEAST ON SUNDAY, WHICH WILL
ALLOW A WARM FRONT TO BEGIN LIFTING INTO THE AREA LATE SUNDAY INTO
SUNDAY NIGHT AS AN AREA OF LOW PRESSURE MOVES INTO THE GREAT LAKES
REGION. AS THE LOW CONTINUES TO LIFT INTO SOUTHEAST CANADA ON
MONDAY, IT WILL DRAG A COLD FRONT ACROSS OUR AREA. SEVERAL SHORT
WAVES/VORTICITY IMPULSES ARE EXPECTED TO AFFECT THE AREA DURING THIS
PERIOD WHICH WILL ALLOW PERIODS OF PRECIPITATION TO OCCUR THROUGH
THE TIME FRAME. WITH COLD AIR IN PLACE, THIS PRECIPITATION WILL
POSSIBLY START OUT AS A WINTRY MIXTURE FOR SUNDAY INTO SUNDAY NIGHT,
BEFORE POSSIBLY CHANGING TO RAIN MONDAY AS WARMER AIR MOVES IN. OUR
NORTHERN ZONES COULD HOLD ON THE THE WINTRY MIXTURE LONGER INTO
MONDAY MORNING AS COLD AIR COULD GET DAMMED UP BEFORE THE WARM SURGE
PUSHES THROUGH. THE PRECIPITATION SHOULD BEGIN TO DISSIPATE MONDAY
NIGHT INTO TUESDAY AS THE FRONTAL BOUNDARY PUSHES FARTHER OFFSHORE.
THERE STILL WILL BE A SMALL CHANCE HOWEVER UNTIL THE FRONT AND IT`S
MOISTURE COMPLETELY PULL AWAY.

DRIER WEATHER IS CURRENTLY EXPECTED FOR WEDNESDAY AS HIGH PRESSURE
BEGINS TO BUILD INTO THE AREA FROM THE WEST. A WEAK CLIPPER SYSTEM
MAY SKIRT TO OUR NORTH ON WEDNESDAY, BUT IS NOT EXPECTED TO AFFECT
OUR AREA.

&&

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

THE 18Z TAFS WILL REMAIN MVFR TO IFR THROUGHOUT WITH MORE OF AN
EMPHASIS ON CLOUDINESS AS BEING THE IMPACTOR.

FOR THIS AFTERNOON THERE IS STILL A PLETHORA OF LOW CLOUDINESS
SOUTH OF THE AREA THAT WILL BE MOVING NORTHWARD. WE KEPT
OCCASIONAL CIGS AS IFR WITH JUST A NARROW WINDOW OF EXCLUSIVE MVFR
LATE. A AT THE NORTHWEST TERMINALS CONFIDENCE IS LOW ABOUT
EVER BECOMING MVFR. SOUTH WINDS WILL AVERAGE 5 TO 10 KTS.

FOR THIS EVENING IFR CIGS WITH MVFR VSBYS PREVAILING. WE ARE
KEEPING SIMILAR WIND SPEEDS AND DIRECTION.

FOR THE OVERNIGHT, CONTINUING IFR CONDITIONS WITH RAIN MOVING IN
AS THE FRONT NEARS. WE WILL CARRY LLWS FOR SEVERAL HOURS
PRECEDING THE CFP AS THE LOW LEVEL JET IS FORECAST TO REACH 40 TO
50 KTS AT 2K. SOUTH TO SOUTHWEST SURFACE WINDS SHOULD REMAIN
RELATIVELY LIGHT AT SPEEDS OF 5 TO 10 KTS.

THERE WILL BE A PERIOD OF IMPROVEMENT TO MVFR CIGS AND VFR VSBYS
AFTER THE COLD FRONT MOVES THRU (APPROXIMATELY 09Z-12Z). NORTHWEST
WINDS SHOULD AVERAGE 10 KTS WITH SOME GUSTINESS FOR A FEW HOURS
FOLLOWING THE CFP.

THE NEXT SHOT OF OVERRUNNING RAIN SHOULD THEN BRING HIGHER
CONFIDENCE MVFR CONDITIONS LATE FRIDAY MORNING AND MORE LIKELY
FRIDAY AFTERNOON. WINDS SHOULD VEER TO THE NORTH AND BECOME
SLIGHTLY LIGHTER.

OUTLOOK...
FRIDAY NIGHT...MVFR/IFR WITH PERIODS OF RAIN IN THE EVENING,
POSSIBLE CHANGING TO WINTRY MIX OVERNIGHT FRIDAY. GUSTY WINDS
15-20 KT POSSIBLE.

SATURDAY-SATURDAY NIGHT...MOSTLY VFR. GUSTY WINDS 15-20 KT POSSIBLE.

SUNDAY-MONDAY NIGHT...MVFR/IFR PROBABLE WITH RAIN/WINTRY MIX
SUNDAY INTO MONDAY. POSSIBLE IMPROVEMENT MONDAY NIGHT.

&&

.MARINE...
WE HAVE EXTENDED THE DENSE FOG ADVISORY TO INCLUDE AREA WATERS.
TRAFFIC CAMS ALONG THE IMMEDIATE COAST ARE ALL SHOWING POOR
VISIBILITIES.

HIGH PRESSURE WILL REMAIN WELL OFFSHORE TODAY AND TONIGHT. LOW
PRESSURE WILL BE WINDING UP OVER THE GREAT LAKES HEADING FOR
ONTARIO. THE PRESSURE GRADIENT OVER THE WATERS SLOWLY IMPROVES
TODAY...BEHIND THE DEPARTING WARM FRONT. IT APPEARS THE LOW-END SCA
GUSTS WILL BE OVER THE WATERS TONIGHT AND THEN THE SEAS WILL BE UP
CLOSE TO 5 FT BY LATE TONIGHT AND INTO FRIDAY. THEREFORE...WE WILL
RAISE THE SCA FLAG FOR TONIGHT AND CARRY IT ON INTO FRI. SCT SHOWERS
TODAY AND A BETTER CHC FOR SHOWERS TONIGHT AS A COLD FRONT
APPROACHES. PATCHY FOG EXPECTED ON THE WATERS TODAY WITH THE HIGHER
DEW POINTS ARRIVING OVER THE CHILLY WATERS.

OUTLOOK...
FRIDAY-MONDAY...SMALL CRAFT ADVISORY, OR NEAR ADVISORY, CONDITIONS
ARE POSSIBLE THROUGH THE PERIOD AS SEAS MAY REMAIN NEAR 4-6 FEET AND
WINDS COULD GUST 20-25 KNOTS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ430-
     431-450>455.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST FRIDAY
     FOR ANZ450>455.

&&

$$
SYNOPSIS...ROBERTSON
NEAR TERM...GIGI/MEOLA/O`HARA
SHORT TERM...O`HARA
LONG TERM...ROBERTSON
AVIATION...GIGI/ROBERTSON/O`HARA
MARINE...GIGI/ROBERTSON/O`HARA