667 
FXUS61 KPHI 060906
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
406 AM EST SUN JAN 6 2013

.SYNOPSIS...
A WEAK WARM FRONT FROM PENNSYLVANIA INTO VIRGINIA WILL PASS EAST OF 
NEW JERSEY JUST AFTER DAYBREAK AS LOW PRESSURE IN THE UPPER GREAT 
LAKES HEADS EAST FOR NORTHERN NEW ENGLAND LATE TODAY. THAT LOW WILL 
TRAIL A COLD FRONT SOUTHWARD INTO THE MID ATLANTIC STATES MONDAY 
MORNING. STRONG HIGH PRESSURE WILL FOLLOW LATE MONDAY INTO EARLY 
THURSDAY...BRIEFLY GIVING WAY TO ANOTHER COLD FRONTAL PASSAGE 
WEDNESDAY AFTERNOON.  THEREAFTER...SOUTHERN PLAINS LOW PRESSURE 
HEADS NORTHEAST INTO THE GREAT LAKES ON FRIDAY AND PULLS ITS WARM 
FRONT JUST TO THE NORTHEAST OF OUR REGION ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FAST MOVING SHORT WAVE IN THE FLOW ALOFT WILL CONTINUE TO BRING 
LIGHT WINTRY PCPN TO THE AREA BEFORE SUNRISE. ONLY THE LIGHTEST OF 
SNOW ACCUMULATIONS ARE EXPECTED. THE PCPN WILL EXIT OFF TO THE 
NORTHEAST EARLY. 

CLOUDS WILL DECREASE THIS MORNING AS THE WEAK SYSTEM MOVES 
AWAY...THE MODELS ARE SHOWING THAT SOME LOW LEVEL MOISTURE MAY 
RETURN LATE TODAY...BUT OVERALL PARTLY TO MOSTLY SUNNY SKIES MUCH OF 
TODAY. HIGH TEMPERATURES WILL REACH THE MID 40S ACROSS THE DELMARVA 
AND MOST OF SRN/ERN NJ WHILE UPPER 30S TO LOW 40S ELSEWHERE. WINDS 
WILL MOSTLY BE FROM THE SW OR W AT AROUND 10 MPH. 

0.3 SFALL AT THE MOUNT HOLLY OFFICE. PAVEMENTS SLUSHY. ALL OTHER
SURFACES WELL COVERED.  WILL UPDATE PNS AS TIME AVAILS AFTER 4AM. 
SPS POSTED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
MOSTLY FAIR WEATHER TONIGHT AS HIGH PRESSURE BUILDS IN FROM THE OHIO 
VALLEY. AN AREA OF MOISTURE MOVING ACROSS THE AREA MAY BRING EXTRA 
CLOUDINESS TO THE REGION...BUT NO ORGANIZED PCPN IS EXPECTED. A FEW 
FLURRIES ARE POSSIBLE HOWEVER. TEMPERATURES WILL DROP INTO THE 20S 
IN MANY AREAS...WITH LOW 30S OVER PHILADELPHIA AND THE DELMARVA. 
WINDS WILL BE W OR NW AT 5 TO 10 MPH.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
CALENDAR AVG TEMPERATURES: ABOVE NORMAL THROUGHOUT THIS 6 DAY PERIOD...
POSSIBLY 10 DEGREES OR MORE ABOVE NORMAL ONE 1 OR TWO DAYS IN THE
PERIOD WED-SAT.

500 MB: TO START THE PERIOD A SHORT WAVE HAS JUST PASSED OFF THE MID 
ATLC COAST WITH WEAK RIDGING FOLLOWING. DEEP CLOSED LOW PRESSURE 
OVER TEXAS ON WEDNESDAY SLOWLY LIFTS NEWD INTO ITS CONFLUENCE ZONE 
WITH THE NORTHERN STREAM. IT THEN WEAKENS AS IT HEADS ACROSS THE 
OHIO VALLEY FRIDAY. THE LARGE SCALE FLOW IS SOUTHWESTERLY NEXT 
WEEKEND INTO A BROAD TROUGH OVER THE PLAINS STATES AND A RIDGE OFF
THE SE COAST OF THE USA INTO THE GMEX. A VERY LARGE SPREAD EXISTS 
REGARDING SHORT WAVE POSITIONING FROM THE WESTERN GREAT LAKES
ACROSS THE NORTHEAST UNITED STATES NEXT WEEKEND.

THE DAILIES...

ALL BELOW IS 00Z/6 BLENDED NCEP HPC EXTENDED AND 00Z/6 GFS MEXMOS
GUIDANCE BLENDED WITH THE PRIOR 330 PM SATURDAY KPHI FCST AND
00Z/6 ECMWF...UNLESS OTRW NOTED.

MONDAY...FAIR AND MAYBE 1 TO 3 DEGREES COOLER THAN SUNDAY BUT STILL 
A BIT ABOVE NORMAL WITH A GUSTY NNW WIND TO 20 MPH THRU MIDDAY. 
NAM METMOS DURING THE DAY...PER EC SUGGESTION OF SLIGHTLY WARMER.
DRIER AND BOUNTIFUL SUNSHINE.  VERY NICE FOR JANUARY!

MONDAY NIGHT...EXCELLENT RADIATOR AND USED THE COLDER MAV NUMBERS
FROM 00Z/8 ONWARD. LIGHT OR CALM WIND-CLEAR SKY. FROSTY! ISOLATED
PATCHY FOG POSSIBLE TOWARD DAWN TUE OR PROBABLY JUST TOO COLD FOR
FOG IN THIS THERMAL ENVIRONMENT?

TUESDAY...MOSTLY CLEAR AND MILDER WITH A SW WIND GUSTY TO 20 MPH
IN THE AFTN. PATCHY CI. ANOTHER BEAUTY.

WEDNESDAY...MOSTLY CLEAR. GUSTY WEST WINDS BECOME NW IN THE AFTN
WITH GUSTING 25 TO 30 MPH...PER A SECONDARY WEAK COLD FRONTAL PASSAGE.
BEST COLD AIR ADVECTION AND MOMENTUM TRANSFER LATE IN THE DAY.

OTHER THAN THIS MORNINGS SNOW AND RAIN...WHICH WILL BE LESS THAN
0.10 MELTED...IT HASNT PRECIPITATED FROM THE 30TH THROUGH PROBABLY
WEDNESDAY THE 9TH. MIN RH ON WEDNESDAY SHOULD BE JUST ABOVE FIRE
WEATHER CRITERIA. HOWEVER...GUSTY WINDS AND RECENT DRYNESS WILL
BE MONITORED FOR MODEST FIRE WEATHER CONCERNS WEDNESDAY AFTERNOON.

MEANWHILE...I DONT HAVE A GOOD READ ON THE THURSDAY-SATURDAY SCENARIO
AS THERE IS QUITE A BIT OF MODEL SPREAD AND MY CONFIDENCE ON
THESE LAST 3 DAYS OF THE FORECAST WRITTEN BELOW IS BELOW AVERAGE. 
THE 00Z/6 ECMWF AND RECENT GEFS TRENDS THROUGH THE 00Z/6 CYCLE INDICATE
THAT IF ITS GOING TO RAIN..IT MAY BE DELAYED TIL FRIDAY.

THURSDAY...INCREASING CLOUDS.  WAA SHOWERS POSSIBLE AT NIGHT WITH
A SSE FLOW.

FRIDAY...WAA SHOWERS POSSIBLE...OTRW A DEVELOPING SSW FLOW.
DAYTIME HIGHS COULD BE 15 DEGREES ABOVE NORMAL IF THE WARM FRONT
PASSES BY TO OUR NORTH BY NOON. CONSIDERABLE CLOUDINESS AND
CONSIDERABLE UNCERTAINTY ON THE DETAILS INCLUDING PROBABILITY OF
RAIN.

SATURDAY...PROBABLY A SW FLOW OF MILD AIR WITH A BACK DOOR COOL
FRONT POSSIBLY POSITIONED NEARBY TO OUR NORTH. DAYTIME HIGHS 
COULD BE 15 DEGREES ABOVE NORMAL...ESPECIALLY IN THE DE/MD SECTOR
OF OUR FCST AREA .

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

LOWER CONDITIONS ARE ACROSS PHL AND OTHER NEARBY TERMINALS EARLY 
THIS MORNING AS -SN HAS DEVELOPED ASSD WITH THE SHORTWAVE ALOFT. 
THIS FEATURE WILL QUICKLY EXIT TO THE NE BEFORE DAWN AND VFR 
CONDITIONS WILL RETURN. SKY MAY BECOME SCT LATER THIS MORNING...BEFORE
ANOTHER BATCH OF LOW/MID LEVEL MOISTURE BRINGS MORE CLOUDS LATER
TODAY AND TONIGHT. VFR CONDITIONS WILL BE OVER THE AREA TODAY AND
TONIGHT. WINDS WILL BE MOSTLY WEST TODAY AT AROUND 10 KTS AND THEN
BECOME NW TONIGHT.

OUTLOOK...
MONDAY...VFR NNW G 15-20 KTS THRU EARLY AFTN THEN NEARLY CALM AT
NIGHT. ISOLATED PATCHES OF COUNTRYSIDE FOG POSSIBLE NEAR 11Z
TUESDAY?

TUESDAY...VFR. MAYBE PATCHY CIRRUS BUT A BEAUTIFUL DAY. SW G15
KT IN THE AFTN.

TUESDAY NIGHT...MAINLY VFR. THERE IS A SMALL CHANCE OF LATE 
NIGHT AND EARLY MORNING VISIBILITY RESTRICTIONS.

WEDNESDAY...VFR.  GUSTY WSW WIND 20 KTS IN THE MORNING BECOME NW G 
25 KTS IN THE AFTN/EVE IN ASSOCIATION WITH A WEAK SECONDARY COLD
FRONTAL PASSAGE WITH BEST COLD AIR ADVECTION AND MOMENTUM TRANSFER
LATE IN THE DAY.

THURSDAY...VFR CIGS WITH POSSIBLE SHOWERS AT NIGHT.  SLY FLOW.

&&

.MARINE...
LOW PRESSURE MOVING BY WELL TO THE NORTH AND HIGH PRESSURE TO THE 
SOUTH WILL KEEP A RATHER RELAXED PRESSURE GRADIENT OVER THE WATERS 
TODAY AND TONIGHT. WINDS MAY INCREASE A BIT TODAY BEHIND THE 
DEPARTING SHORTWAVE...BUT SPEEDS SHOULD STAY MOSTLY IN THE 10 TO 15 
KT RANGE. SEAS...RATHER LIGHT FOR WINTER...PRESENTLY 1-2 FT ON THE 
OCEAN. THESE MAY INCREASE A FOOT TODAY.  

OUTLOOK...
MONDAY-TUESDAY...SCA NW GUSTS 20 TO 25 KTS POSSIBLE TO START MONDAY
MORNING...BUT MARGINAL AND NO SCA ATTM. THEN LIGHT WIND MONDAY NIGHT
BECOME G SW 15-20 KTS TUESDAY AFTN.

WEDNESDAY...A BETTER CHC OF SCA CONDITIONS IS EMERGING WEDNESDAY 
AFTERNOON WITH MORNING WINDS WSW GUST 15-20 KTS SHIFTING NW G25-30
KTS IN THE AFTN/EVE.

THURSDAY...SOUTH OR SOUTHEAST FLOW DEVELOPING.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DRAG
NEAR TERM...O'HARA
SHORT TERM...O'HARA
LONG TERM...DRAG 406A
AVIATION...DRAG/O'HARA
MARINE...DRAG/O'HARA