-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPHI 091137
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
637 AM EST MON DEC 9 2013

.SYNOPSIS...
A  LOW PRESSURE SYSTEM WILL MOVE THROUGH THE GREAT LAKES REGION
TODAY, DRAGGING A COLD FRONT THROUGH OUR AREA AS ANOTHER LOW
PRESSURE SYSTEM CONTINUES TO MOVE UP ALONG THE MIDDLE ATLANTIC
COAST. A SECONDARY FRONT WILL MOVE THROUGH THE REGION LATE TUESDAY
INTO WEDNESDAY. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FROM
THE WEST ON WEDNESDAY BEFORE SHIFTING EAST OF THE AREA AT THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
THE AREA IS STILL FEELING TH IMPACT OF THE LOW PRESSURE THAT WILL
GRADUALLY DEPART THE REGION LATER TODAY.  THE WELL ADVERTISED, BUT
MAJORLY DELAYED, CHANGE TO RAIN OF THE PRECIPITATION HAS BEGUN.
AREAS FROM PHL S AND E ARE NOW RAIN, ALBEIT A VERY COLD RAIN.  TEMPS
ARE ABOVE FREEZING IN ALL OF THESE LOCATIONS.  THE RAIN LINE WILL
SLOWLY (EMPHASIS NEEDED) WORK ITS WAY NWWD THRU THE MRNG AND INTO
THE AFTN.  WHERE TEMPS HAVE RISEN ABV FREEZING, THE ADVY HAS BEEN
DROPPED.  WILL CONTINUE TO PARE OF PIECES OF THE ADVY THRU THE MRNG
HOURS.  ALSO EXTENDED THE EXPIRATION TIME OF SOME OF THE MORE NRN
AND WRN SECTIONS DUE TO THE TEMPS IN THE 20S IN THOSE LOCATIONS.

PRECIP SHOULD BEGIN TO WIND DOWN BY LATE MRNG ERLY AFTN AND BE OVER
WITH BY EVE, IF NOT SOONER.

WITH SNOW COVER IN SOME AREAS AND AN ABUNDANCE OF CLOUDS, WENT BELOW
MOS GUID BY A FEW DEGREES.  THE GFS SEEMED WAY TO WARM AS IT WAS
DURG THIS ENTIRE EVENT.  THE NAM MOS WAS COOLER AND WENT BELOW EVEN
THAT.

BASED ON THE LATEST TEMPS WILL REMOVE A FEW MORE NJ COUNTIES FROM
THE WINTER WX ADVY. SEVERAL OTHER AREAS REMAIN RIGHT AT 32
DEGREES. ONCE THEY CLIMB ABOVE THE MAGIC NUMBER ADDITIONAL
COUNTIES WILL BE ABLE TO BE TAKEN OUT LATER TODAY.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT WILL BE THE LULL AS THE CURRENT SYS MOVES OUT AND HIGH
PRESSURE RIDGES IN FROM THE MID SECTION OF THE COUNTRY.  HOWEVER, BY
MRNG, SOME PRECIP CUD BE APPROACHING THE SRN ZONES ASSOCD WITH THE
NEXT SYS.  THE GFS IS A LOT MORE ROBUST WITH ITS PRECIP SHIELD THAN
THE NA,/WRF AND ECMWF AND WENT WITH A MORE CONSERVATIVE PRECIP
SHIELD AND CONFINED IT MAINLY TO THE DELMARVA AND SRN NJ TWD THE END
OF THE PD.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
WITH THE ONGOING WEATHER IN THE NEAR TERM DECIDED TO NOT ADJUST THE
LONGTERM PORTION OF THE FORECAST TOO MUCH BEYOND THURSDAY GIVEN THE
ARCTIC HIGH THAT WILL BE ENCOMPASSING THE REGION. INSTEAD WANTED TO
FOCUS A BIT MORE ON THE NEXT AND LAST EVENT IN THIS SERIES OF
SURFACE WAVES...TUESDAY.

THE GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT SHOWING ANOTHER
QUICK MOVING WAVE DEVELOPING ALONG THE VERY OLD BAROCLINIC ZONE TO
OUR SOUTHEAST. THIS CONDUIT HAS CONTINUED TO USHER MOISTURE INTO THE
REGION FOR THE PAST SEVERAL DAYS AND WILL GIVE ONE LAST HOORAH
DURING THE DAYTIME HOURS ON TUESDAY. THERMAL PROFILES ACROSS A
BETTER PORTION OF THE REGION SHOW WE ARE COLD ENOUGH FOR ALL SNOW
AND BY THE LATE MORNING HOURS CLOUD TEMPERATURES DROP TO -40C SO
THERE WILL BE ICE IN THE CLOUD...NEEDED FOR SNOW. DYNAMICALLY
SPEAKING THE REGION IS IN A PRIME LOCATION FOR LARGE SCALE LIFT WITH
A PASSING UPPER LEVEL JET AND US IN ITS RIGHT REAR QUADRANT AND THE
STRUNG OUT MID-LEVEL CHANNELIZED VORTICITY. DEEP SOUTHWEST SURGE IN
THE LOW AND MID-LEVELS SHOULD ALLOW FOR AT LEAST A QUARTER INCH OF
LIQUID TO STREAM IN, THOUGH THE HIGHER RES GUIDANCE HAS MUCH MORE.

IN THE SNOW GROWTH REGION THERE IS A DECENT AMOUNT OF WIND TO ALLOW
FOR SOME CRYSTAL FRACTURING WHILE SOME OMEGA DOES EXIST JUST BELOW
THIS LAYER...GOOD FOR GROWTH. DID NOT WANT TO GO CRAZY WITH QPF AND
ULTIMATELY SNOW TOTALS AT THIS POINT...CAN`T MAKEUP FOR SUNDAYS
FORECAST NOW. EITHER WAY EXPECTING GREATER THAN THE 10:1 RATIO GIVEN
THE LIFTING AND COLDER PROFILES PLACE. TOTALS AS ALWAYS ARE SUSPECT
BUT IT DOES APPEAR THAT SOME 850-700MB FGEN FORCING WILL PUSH
THROUGH FROM SOUTHWEST TO NORTHEAST ACROSS THE CENTRAL PORTIONS OF
THE CWA AND THIS WHERE THE HEAVIEST SNOW WILL FALL.

AFTER THE QUICK SHOT OF SNOW ON TUESDAY ANOTHER ARCTIC HIGH PRESSURE
NOSES IN AND CLEANS US OUT. TEMPERATURES REALLY TAKE A DOWNWARD
TREND THROUGH THE END OF THE WEEK WITH THURSDAY LOOKING TO BE THE
COLDEST DAY OF THE WEEK...MAY NOT REACH MUCH ABOVE THE FREEZING MARK
ACROSS A BETTER PORTION OF THE CWA. A SLIGHT MODERATION IS THEN
EXPECTED BY SATURDAY AS THE FLOW BEGINS TO VEER SLIGHTLY TOWARDS THE
WEST-SOUTHWEST. THE NEXT POTENTIAL SYSTEM LOOKS TO SKIRT BY THE
COAST SATURDAY NIGHT INTO SUNDAY THROWING SOME MOISTURE BACK ACROSS
THE REGION.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VERY POOR CONDS WERE OCCURRING ACRS THE REGION.  MOST LOCATIONS WERE
IFR OR LIFR IN RAIN OR FREEZING RAIN.  EXPECT THESE CONDS TO
CONTINUE THRU MUCH OF THE DAY.  THERE WILL BE SOME IMPROVEMENT TWD
LATE AFTN OR ERLY EVENING WITH A RETURN TO MVFR AND VFR OVERNIGHT.

OVERALL, ANOTHER BAD DAY FOR THE AVIATION COMMUNITY.  WIND WILL
GENLY BE NE AROUND 10 KT AND BECOME MORE SE 5 TO 10 KTS DURG THE
MRNG AND THEN W 5 TO 10 KTS DURG THE AFTN AND EVENING AS DRIER AIR
MOVES IN.

OUTLOOK...
TUESDAY...HIGHER CONFIDENCE ON MVFR/IFR RESTRICTIONS IN SNOW DURING
THE LATE MORNING/EARLY AFTERNOON HOURS AT OUR TERMINALS. WINDS WILL
GENERALLY BE OUT OF THE NORTHWEST AROUND 5 TO 10 KNOTS. WE BECOME
VFR BY LATE IN THE EVENING.

WEDNESDAY - FRIDAY...VFR.

&&

.MARINE...
THE SCA FLAG ON THE OCEAN HAS BEEN EXTENDED UNTIL 6PM.  SEAS WERE
AROUND 6 FT AT BUOY 44009.  CONDS WILL GRADUALLY DECREASE DURG THE
DAY AS LOW PRES PASSES OFFSHORE.  WIND WILL INCREASE AGAIN BY TUE
MRNG AS ANOTHER SYS BEGINS TO APPROACH FROM THE SW AND ANOTHER SCA
MAY BE NEEDED ON THE HEELS OF THIS ONE.

OUTLOOK...
TUESDAY - WEDNESDAY...A FAIRLY TIGHT GRADIENT WILL PERSIST THROUGH
WEDNESDAY WITH WINDS PICKING UP OUT OF THE WEST OR NORTHWEST. WE
SHOULD HAVE ENOUGH MIXING TO BRING SOME HIGHER WINDS FROM ALOFT TO
THE SURFACE AND WE MAY NEAR GALE FORCE GUSTS TUESDAY NIGHT AND
WEDNESDAY MORNING, ESPECIALLY ACROSS THE NORTHERN OCEAN WATERS.
CONFIDENCE IS HIGH THAT A SMALL CRAFT WILL BE NEEDED BUT NOT THAT
HIGH FOR POTENTIAL GALES.

THURSDAY AND FRIDAY...WINDS AND SEAS WILL SUBSIDE BELOW SMALL CRAFT
ADVISORY LEVELS AS HIGH PRESSURE BUILDS ACROSS THE REGION AND REMAIN
BELOW AS WE END THE WORK WEEK.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ101-
     103>106.
     WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     PAZ054-055.
     WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
     PAZ060>062.
NJ...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ009.
     WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     NJZ001.
     WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
     NJZ007-008.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
     ANZ450>455.
-- End Changed Discussion --

&&

$$
SYNOPSIS...HEAVENER/MEOLA
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...HEAVENER
AVIATION...HEAVENER/NIERENBERG/MEOLA
MARINE...HEAVENER/NIERENBERG/MEOLA