Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 300809
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
409 AM EDT THU OCT 30 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER OUR REGION TODAY. BY TOMORROW, A LOW
WILL BEGIN TO DIG SOUTHEAST FROM THE GREAT LAKES REGION. AT THE SAME
TIME, AN OFF SHORE LOW WILL LIFT NORTHEAST. BY SATURDAY NIGHT, THE
TWO LOWS WILL MERGE OFF SHORE RESULTING IN COOL AND UNSETTLED
WEATHER FOR OUR REGION. HIGH PRESSURE WILL THEN BUILD IN EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOG HAS DEVELOPED OVERNIGHT DUE TO THE MOIST LOW LEVELS LEFT OVER
FROM THE LIGHT RAIN YESTERDAY, AND THERE IS SOME DENSE FOG WITH
VISIBILITIES LESS THAN ONE HALF MILE. HOWEVER, LOOKING AT TRAFFIC
CAMERAS AND THE SATELLITE FOG TOOL, IT LOOKS LIKE THE DENSE FOG IS
PATCHY ENOUGH TO PRECLUDE THE NEED FOR A DENSE FOG ADVISORY FOR NOW.
ALSO, DRIER AIR IS EXPECTED TO FILTER ACROSS THE AREA OVER THE NEXT
FEW HOURS, WHICH SHOULD HELP DISSIPATE THE FOG SOME. SO WE`LL KEEP
WITH THE SPS.

ONCE THE FOG BURNS OFF AFTER SUNRISE, TODAY SHOULD END UP BEING A
PRETTY NICE DAY AS HIGH PRESSURE BUILDS TO OUR WEST AND TRIES TO
PUSH INTO OUR WESTERN AREAS. A SHORT WAVE/VORT MAX WILL MOVE
THROUGH THE AREA THIS MORNING, ALTHOUGH NO PRECIP IS EXPECTED ACROSS
OUR AREA AS ANY PRECIP TO THE NORTHWEST SHOULD DISSIPATE BEFORE IT
GETS HERE. BEHIND THIS, THERE COULD BE SOME STRATOCU MOVE DOWN
ACROSS THE AREA FROM THE NORTHWEST, ESPECIALLY ACROSS OUR
NORTHWESTERN AREAS.

HIGHS TODAY WERE A BLEND OF MAV/MET MOS AND BLENDED ECMWF 925MB
TEMPS WHICH KEEPS EVERYONE PRETTY CLOSE TO NORMAL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
HIGH PRESSURE WILL DISSIPATE AS IT MOVES INTO OUR AREA OVERNIGHT,
ALTHOUGH WE ARE STILL EXPECTING A QUIET NIGHT. ANY CLOUDS FROM THE
DAY SHOULD DISSIPATE AFTER SUNSET AND MOSTLY CLEAR SKIES ARE
EXPECTED EARLY IN THE NIGHT, BEFORE A RETURN OF SOME CLOUDS
OVERNIGHT. OVERNIGHT LOWS WERE A BLEND OF MAV/MET MOS WHICH KEEPS
EVERYONE PRETTY CLOSE TO NORMAL.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE BIGGEST STORY THROUGH THE LONG TERM WILL BE THE LOW THAT DIGS
SE FROM THE GREAT LAKES REGION FRIDAY, SLIDING OFF THE CAROLINA
COAST SATURDAY AND MERGING WITH AN OFF SHORE LOW.

FRIDAY AND FRIDAY NIGHT...THOUGH WE WILL TECHNICALLY STILL BE IN
THE WARM SECTOR OF THE SYSTEM, IT WON`T FEEL MUCH LIKE IT. THANKS
TO THE OFF SHORE SURFACE LOW, ONSHORE FLOW IS EXPECTED TO DEVELOP
RATHER EARLY IN THE DAY FRIDAY LEADING TO COOL AND CLOUDY WEATHER.
EXPECT MOST LOCATION TO SEE HIGHS IN THE 50S, WITH THE EXCEPTION
OF THE HIGHER TERRAIN OF THE POCONOS IT LIKELY WON`T GET OUT OF
THE 40S. PRECIP ASSOCIATED WITH THE CONTINENTAL LOW COULD BEGIN
TO MOVE INTO THE POCONOS FROM THE WEST AS EARLY AS FRIDAY
AFTERNOON. MEANWHILE, THE ONSHORE FLOW COULD RESULT IN LIGHT
PRECIP ALONG THE COAST. BY FRIDAY NIGHT, EXPECT THE ONSHORE, AND
UPSLOPE FLOW TO RESULT IN LIGHT PRECIP FURTHER INLAND.

SATURDAY AND SATURDAY NIGHT...THE NOW OCCLUDED COLD FRONT WILL
MOVE THROUGH ON SATURDAY, BRINGING SLIGHTLY COOLER CONDITIONS. ONE
INTERESTING THING TO WATCH WILL BE HOW QUICKLY THE DRIER AIR MOVES
IN. IF THE MID AND UPPER LEVELS DRY OUT AS QUICKLY AS THE GFS IS
SUGGESTING, SNOW SEEMS VERY UNLIKELY AS BY LATE SATURDAY EVENING,
ONLY THE BOUNDARY LAYER WILL BE NEARLY SATURATED. THIS WOULD
SUGGEST MORE OF A DRIZZLE/FREEZING DRIZZLE EVENT. HOWEVER, THE
ECMWF AND NAM STILL SHOW SOME CHANCE OF SEEDER FEEDER CLOUDS
THROUGH AT LEAST 09Z, WHICH COULD LEAD TO A BRIEF PERIOD OF SNOW
FOR THE POCONOS AND LEHIGH VALLEY. EVEN IF PRECIP DOES CHANGE
OVER, PRECIP AMOUNTS ARE EXPECTED TO BE VERY LIGHT.

SUNDAY NIGHT...AS SKIES CLEAR AND WINDS BEGIN TO DECREASE, THIS
WILL SET THE STAGE FOR PRIME RADIATIONAL COOLING CONDITIONS. AS A
RESULT...EXPECT MUCH OF THE REGION TO SEE LOWS NEAR OR BELOW
FREEZING, INCLUDING THE 15 REMAINING COUNTIES (PRIMARILY IN
DELMARVA, THE URBAN CORRIDOR, AND FAR SOUTHERN NJ) THAT HAVE NOT
YET HAD A HARD FREEZE.

MONDAY THROUGH TUESDAY...A BROAD HIGH AMPLITUDE RIDGE BEGINS TO
BUILD EAST. EXPECT MODEST WARMING EACH DAY THANKS BOTH TO AIR MASS
MODIFICATION AD INCREASING 1000-500MB THICKNESSES.

WEDNESDAY AND THURSDAY...COULD SEE AN UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT MOVE THROUGH THE REGION DURING THIS TIME.
HOWEVER BOTH THE GFS AND ECWMF ARE DISAGREE ABOUT TIMING AND TRACK
OF THIS FEATURE. THUS, HAVE STAYED CLOSE TO THE PREVIOUS FORECAST.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

FOG HAS DEVELOPED AT ALL AIRPORTS THIS MORNING DUE TO THE MOIST LOW
LEVELS LEFT OVER FROM THE LIGHT RAIN FROM YESTERDAY. LIFR VSBYS ARE
OCCURRING AT MOST OF THE SITES AS WELL. DRIER AIR IS STILL EXPECTED
TO FILTER ACROSS THE AREA WHICH SHOULD HELP DISSIPATE THE FOG SOME,
ALTHOUGH WE STILL EXPECT IFR VSBYS THROUGH SUNRISE. THE FOG SHOULD
CONTINUE TO DISSIPATE AFTER SUNRISE AND LIFT/DISSIPATE COMPLETELY
THROUGH THE MID-MORNING HOURS. THEN A VFR FORECAST IS EXPECTED FOR
THE REMAINDER OF THE PERIOD. THERE SHOULD BE SOME CLOUD COVER MOVE
IN ACROSS THE AREA FROM THE NORTHWEST DURING THE DAY WITH BASES
AROUND 4,000-5,000 FEET, AND SHOULD VARY FROM BROKEN TO SCATTERED
FROM NORTHWEST TO SOUTHEAST. WE DO NOT EXPECT ANY FOG TO DEVELOP
OVERNIGHT AS THE LOW LEVELS SHOULD BE DRY ENOUGH TO PREVENT FOG
FORMATION.

LIGHT AND VARIABLE WINDS EARLY EARLY WILL BECOME NORTHWEST 5-10
KNOTS THROUGH THE MORNING AND CONTINUE THROUGH THE DAY. WINDS MAY
BECOME LIGHT AND VARIABLE AGAIN OVERNIGHT, WITH ANY DIRECTION
BECOMING MORE NORTHERLY OVERNIGHT.

OUTLOOK...
FRIDAY...EXPECT CEILING TO LOWER THROUGH THE DAY, BECOMING MVFR AT
LEAST BY FRIDAY EVENING. -SHRA COULD MOVE IN BY FRIDAY NIGHT
RESULTING IN OCCASIONAL MVFR VISIBILITIES AS WELL

SATURDAY...IFR CEILINGS ARE POSSIBLE BY SATURDAY MORNING. BREEZY
NORTHERLY WINDS POSSIBLE.

SATURDAY NIGHT...CONDITIONS WILL SLOWLY IMPROVE FROM WEST TO EAST
THROUGH THE NIGHT. BREEZY NW WINDS MAY CONTINUE ESPECIALLY AT ACY.

SUNDAY AND MONDAY...MOSTLY VFR CONDITIONS.


&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED ACROSS THE WATERS
THROUGH TONIGHT AS HIGH PRESSURE NOSES IT`S WAY ACROSS THE AREA FROM
THE WEST.

OUTLOOK...
FRIDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.

FRIDAY NIGHT THROUGH SUNDAY...WINDS WILL BUILD INTO SCA CRITERIA,
AND THEN GALES, WITH PEAK GUSTS NEAR 40KT POSSIBLE DURING THE DAY
ON SATURDAY. GALE CONDITIONS COULD CONTINUE THROUGH MUCH OF THE DAY
SUNDAY.

SUNDAY NIGHT INTO MONDAY...WINDS WILL STAY IN SCA CRITERIA THROUGH
THIS PERIOD.

&&

.TIDES/COASTAL FLOODING...
AN ONSHORE COMPONENT OF THE BREEZY TO WINDY CONDITIONS ON SATURDAY
WILL LEAD TO ELEVATED WATER LEVELS THIS WEEKEND. MINOR TIDAL
FLOODING MAY OCCUR WITH THE HIGH TIDE CYCLES SATURDAY AND SATURDAY
NIGHT.

&&

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

&&

$$
SYNOPSIS...JOHNSON
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...JOHNSON
AVIATION...JOHNSON/ROBERTSON
MARINE...JOHNSON/ROBERTSON
TIDES/COASTAL FLOODING...






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