620
FXUS61 KPHI 161723
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1223 PM EST TUE DEC 16 2025
SYNOPSIS
ARCTIC HIGH PRESSURE OVER THE MID-ATLANTIC SETTLES OVER THE
SOUTHEAST STATES THROUGH TONIGHT BEFORE MOVING OUT TO SEA. A WEAK
FRONT PASSES THROUGH WEDNESDAY EVENING, THEN A STRONG COLD FRONT
MOVES THROUGH OUR REGION THURSDAY NIGHT AND FRIDAY. HIGH PRESSURE
RETURNS INTO THE WEEKEND, HOWEVER A WEAK COLD FRONT PASSES THROUGH
SUNDAY NIGHT. HIGH PRESSURE ONCE AGAIN BUILDS IN FOR MONDAY.
NEAR TERM /THROUGH WEDNESDAY/
THE HIGH PRESSURE SYSTEM THAT HAS BEEN IN CONTROL IS NOW
SETTLING OVER THE SOUTHEAST US BEFORE SLIDING OFFSHORE TODAY
INTO TONIGHT. DUE TO THE HIGH PRESSURE SYSTEM MOVING OFFSHORE,
WE SEE THE WINDS THROUGH THE DAY CHANGE FROM OUT OF THE WEST TO
EVENTUALLY SOUTHWEST LATE IN THE DAY. ALTHOUGH WE SEE THAT
SOUTHWESTERLY WIND, IT IS LATE IN THE DAY AND WE STILL HAVE A
SOLID SNOWPACK, SO TEMPERATURES ONLY MODERATE SLIGHTLY. HIGHS
TODAY WILL BE MAINLY IN THE MID 20S TO MID 30S. THE INFLUENCE OF
THE HIGH PRESSURE SYSTEM WILL ALLOW FOR MINIMAL CLOUD COVER
THIS MORNING. SOME MID AND HIGH CLOUDS LOOK TO INCREASE THIS
AFTERNOON AND EVENING WITH A SIGNAL FOR A PIECE OF UPPER-LEVEL
ENERGY TO ROTATE THROUGH THE REGION. PRECIPITATION IS NOT
EXPECTED AS THIS DISTURBANCE MOVES THROUGH.
AS THE HIGH PRESSURE SYSTEM CONTINUES TO EXIT TONIGHT, IT ALLOWS FOR
A CLEAR SKY WITH WINDS RELATIVELY LIGHT. WHEN COMBINED WITH THE
LINGERING SNOWPACK, THIS WILL ALLOW TEMPERATURES TO RADIATE DOWN
INTO THE TEENS AND LOW 20S.
ONCE THE HIGH FULLY EXITS, WE SEE SOME UPPER-LEVEL TROUGHING THAT
MOVES INTO THE NORTHEAST WEDNESDAY. AT THE SURFACE, THERE IS A LOW
PRESSURE SYSTEM IN THE GREAT LAKES REGION WHICH MOVES INTO THE
NORTHEAST. A WEAK COLD FRONT ASSOCIATED WITH THIS LOW PASSES
THROUGH THE AREA WEDNESDAY. CLOUDS DO INCREASE AHEAD OF THIS
COLD FRONT WEDNESDAY BUT THE FRONTAL PASSAGE LOOKS OVERALL
PRETTY DRY. A SOUTHWEST WIND AHEAD OF THE COLD FRONT WILL ALLOW
TEMPERATURES TO RISE INTO THE 40S FOR MANY. AS THE COLD FRONT
PASSES THROUGH, WE SEE THE WINDS SHIFT TO BE MORE OUT OF THE
WEST WHICH WILL START TO USHER IN COLDER AIR. THERE WILL BE A
TIGHTENING PRESSURE GRADIENT BETWEEN THE DEPARTING HIGH AND THE
LOW MOVING INTO THE NORTHEAST. ALSO, THERE ARE STRONGER WINDS
ALOFT BUT THE POTENTIAL FOR THESE WINDS TO MIX DOWN MAY BE
LIMITED DUE TO THE MILDER AIR FILTERING IN. OVERALL, WIND GUSTS
LOOK TO BE 20-25 MPH ON WEDNESDAY WITH OCCASIONAL GUSTS TO 30
MPH IN THE HIGHER ELEVATIONS.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/
HIGH PRESSURE MOVES OVERHEAD ON WEDNESDAY NIGHT, RESULTING IN MOSTLY
CLEAR SKIES AND LIGHT WINDS. THIS WILL BRING A PERIOD OF IDEAL
RADIATIONAL COOLING CONDITIONS, ALBEIT NOT FOR THE ENTIRE NIGHT AS
THERE WILL BE A BIT OF A GRADIENT IN PLACE UNTIL THE HIGH MOVES
OVERHEAD. THIS WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER
TEENS/LOW TWENTIES, WITH MID TO UPPER 20S ALONG THE COAST AND OVER
LOWER DELMARVA.
HIGH PRESSURE MOVES OFFSHORE BY THURSDAY, WITH RETURN FLOW SETTING
UP AND WARM-AIR ADVECTION STRENGTHENING. TEMPERATURES CLIMB INTO THE
50S WITH SOUTHERLY FLOW TAKING HOLD AHEAD OF A STRONG COLD FRONT.
CLOUD COVER INCREASES AHEAD OF THE APPROACHING FRONTAL SYSTEM AS THE
DAY GOES ON, THOUGH THINGS SHOULD STAY DRY THROUGH THE DAYTIME
HOURS.
RAIN MOVES IN ON THURSDAY NIGHT, SOME OF WHICH COULD BE HEAVY AT
TIMES. SOME GUIDANCE EVEN INDICATES A POTENTIAL SQUALL LINE SETTING
UP, AND WITH A STRONG WIND FIELD ALOFT, IT WOULD NOT TAKE MUCH FOR
SOME STRONGER GUSTS TO MAKE IT TO THE SURFACE. OVERALL THOUGH,
SEVERE PROBABILITIES REMAIN LOW WITH INSTABILITY LACKING, AND THIS
SHOULD PRIMARILY BE A BENEFICIAL RAIN. EVEN WITH MILD TEMPERATURES
AND A SNOWPACK IN PLACE, ENSEMBLE RIVER FORECASTS SHOW LESS THAN A
10% CHANCE OF STREAMS/RIVERS GETTING TO ACTION STAGE WITH THE RAIN +
ENSUING SNOWMELT. NBM PROBABILITIES OF 1" OR MORE OF RAIN HOVER
AROUND 40-60% FOR MOST OF THE REGION. THERE COULD BE A BIT OF A
RAIN/SNOW MIX ON THE BACKSIDE OF THE PRECIPITATION SHIELD, BUT NO
SIGNIFICANT SNOW ACCUMULATION IS ANTICIPATED.
LONG TERM /FRIDAY THROUGH MONDAY/
A STRONG COLD FRONT WILL MOVE THROUGH EARLY ON FRIDAY, WITH
MODEST COLD-AIR ADVECTION AND GUSTY WINDS IN ITS WAKE.
TEMPERATURES ACTUALLY SHOULD BE ON THE DECLINE THROUGH THE DAY
ON FRIDAY WITH WIND GUSTS UPWARD OF 30-40 MPH. MAY NEED TO
CONSIDER A WIND ADVISORY AT SOME POINT, WITH PROBABILITY OF MAX
GUSTS OVER 40 KT AROUND 20-25%. ANY PRECIPITATION LIKELY MOVES
OUT BY MIDDAY.
BREEZY WINDS LIKELY CONTINUE THROUGH AT LEAST PART OF FRIDAY NIGHT,
THOUGH THE GRADIENT SHOULD BE WEAKENING WITH HIGH PRESSURE MOVING
IN. LOWS ON FRIDAY NIGHT SHOULD DROP INTO THE LOW TO MID 20S.
SATURDAY AND SUNDAY ACTUALLY LOOK PRETTY QUIET WITH HIGH PRESSURE
MOVING IN. TEMPERATURES LOOK TO BE MORE SEASONABLE ON SATURDAY, WITH
A POTENTIAL RETURN TO ABOVE NORMAL TEMPERATURES POSSIBLE ON SUNDAY.
IT SHOULD MAINLY BE DRY, THOUGH A WEAK FRONTAL SYSTEM COULD BRING
SOME PRECIPITATION LATE SUNDAY INTO MONDAY. THAT FRONT ALSO LIKELY
DROPS TEMPERATURES BACK TO NEAR NORMAL LEVELS TO START NEXT WEEK.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 00Z...VFR. WEST-SOUTHWEST WIND AROUND 5 KT. HIGH
CONFIDENCE.
TONIGHT...VFR. WIND BECOMING LGT/VRB WITH PERIODS OF CALM
POSSIBLE. HIGH CONFIDENCE.
WEDNESDAY...VFR. SCT MID-LEVEL CLOUDS AFTER 15-17Z. SOUTHWEST
WIND AROUND 5 KT INCREASING TO AROUND 10 KT WITH GUSTS 20-25 KT
DURING THE AFTERNOON. LLWS POSSIBLE BETWEEN 13Z AND 17Z FOR KRDG
AND KABE. LOWER CONFIDENCE IN LLWS FOR THE I-95 TERMINALS.
MODERATE CONFIDENCE.
OUTLOOK...
THURSDAY...VFR. NO SIGNIFICANT WEATHER EXPECTED.
THURSDAY NIGHT...MVFR/IFR CONDITIONS EXPECTED WITH PERIODS OF RAIN
AND LOW CLOUDS MOVING THROUGH. A STRONG LOW-LEVEL JET OVERHEAD COULD
RESULT IN SOME LLWS. SOUTHERLY WIND GUSTS 20-25 KT EXPECTED.
FRIDAY...SUB-VFR CONDITIONS POSSIBLE (50%) IN THE MORNING, IMPROVING
TO VFR AT SOME POINT IN THE DAY. WIND GUSTS OUT OF THE
WEST/NORTHWEST 30-35 KT EXPECTED.
FRIDAY NIGHT...VFR. WIND GUSTS GRADUALLY DIMINISHING AS THE NIGHT
GOES ON THOUGH GUSTS 20-25 KT ANTICIPATED FOR THE FIRST HALF OF THE
NIGHT.
SATURDAY...VFR. NO SIGNIFICANT WEATHER.
MARINE
NO MARINE HEADLINES ARE EXPECTED THROUGH TUESDAY NIGHT.
FOR TODAY, A WEST-NORTHWEST WIND AROUND 10-15 KT EARLY WILL LESSEN
TO 5-10 KT THROUGH THE DAY WITH SEAS OF 1-3 FEET EXPECTED. FAIR
WEATHER.
OVERNIGHT TUESDAY, WINDS WILL INCREASE OUT OF THE SOUTHWEST AT 15-20
KT AND SEAS INCREASE TO 2-4 FEET.
ON WEDNESDAY, MARGINAL SCA CONDITIONS ARE POSSIBLE WITH GUSTS NEAR
25 KT AND SEAS BUILDING TO 4-5 FEET.
OUTLOOK...
WEDNESDAY NIGHT THROUGH THURSDAY...NO MARINE HEADLINES EXPECTED.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...A PERIOD OF GALE FORCE WINDS
ARE LIKELY (60-80%) WITH SOUTHERLY WINDS AHEAD OF A COLD FRONT
POTENTIALLY GUSTING UP TO 40 KT ON THURSDAY NIGHT AND THEN A PERIOD
OF WEST/NORTHWEST WINDS ON FRIDAY AND FRIDAY NIGHT GUSTING UP TO 40
KT. SEAS WILL GENERALLY BE AROUND 5 TO 9 FEET.
SATURDAY...NO MARINE HEADLINES EXPECTED.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...HOEFLICH/MPS
NEAR TERM...GUZZO
SHORT TERM...HOEFLICH
LONG TERM...HOEFLICH
AVIATION...COOPER/HOEFLICH
MARINE...GUZZO/HOEFLICH
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