402
FXUS61 KPHI 041728
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1228 PM EST SUN JAN 4 2026
SYNOPSIS
A WEAK AREA OF LOW PRESSURE TRACKS TO OUR NORTH THIS MORNING. HIGH
PRESSURE BUILDS IN FOR MONDAY BEFORE SHIFTING OFFSHORE INTO TUESDAY.
A WEAK SYSTEM WITH A WARM FRONT SLIDES TO OUR NORTH LATER MONDAY
INTO TUESDAY, THEN A COLD FRONT CROSSES OUR AREA BY LATER WEDNESDAY.
HIGH PRESSURE BRIEFLY ARRIVES ON THURSDAY, FOLLOWED BY A WARM FRONT
LIFTING NORTH ACROSS OUR AREA DURING FRIDAY. LOW PRESSURE WITH A
COLD FRONT ARRIVES DURING SATURDAY.
NEAR TERM /THROUGH TONIGHT/
CLOUDS BREAK FOR A DECENT AMOUNT OF SUNSHINE TODAY AS THE
SYSTEM'S FRONT PASSES THROUGH AND HIGH PRESSURE BEGINS BUILDING
BACK IN FROM THE WEST. WINDS MAY GUST UP TO AROUND 20 MPH BY
THIS AFTERNOON, BUT OVERALL NOT TOO BAD A DAY, ESPECIALLY WITH
TEMPS LIKELY NUDGING A FEW DEGREES WARMER THAN YESTERDAY AND A
LOT MORE SUNSHINE OVERALL. HIGHS MOSTLY MID- UPPER 30S, NEAR 40
SOUTHERN DELAWARE BUT STILL UPPER 20S IN THE POCONOS.
TONIGHT, MOSTLY CLEAR SKIES EARLY BEGIN CLOUDING BACK UP AHEAD
OF ANOTHER WEAK IMPULSE. HOWEVER, DON'T THINK ANY PRECIP ARRIVES
BEFORE DAWN (IF EVER). RADIATIONAL COOLING EARLY THANKS TO LIGHT
WINDS UNDER HIGH PRESSURE WILL ALLOW TEMPS TO DIVE WELL DOWN
INTO THE 20S, WITH TEENS IN THE COLDER SPOTS ESPECIALLY POCONOS
AND NW NJ.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
SURFACE HIGH PRESSURE SHIFTS OFFSHORE DURING THE DAY MONDAY AS A
SHORTWAVE SLIDES ACROSS THE INTERIOR NORTHEAST. THIS WAVE WILL
INCREASE THE WARM AIR ADVECTION AND ASSOCIATED ISENTROPIC LIFT,
PRODUCING AN AREA OF LIGHT SNOW. THIS SHOULD SLIDE ACROSS PORTIONS
OF OUR NORTHERN ZONES (MOSTLY NORTH OF A LINE FROM ABOUT FROM
ALLENTOWN, PA TO TRENTON, NJ). TIMING OF THIS LOOKS TO OCCUR MOSTLY
DURING THE AFTERNOON ON MONDAY, BEFORE ENDING BY EARLY MONDAY
EVENING. SOME GUIDANCE HOWEVER IS STRONGER WITH THE ISENTROPIC LIFT
WHICH BRINGS THE LIGHT SNOW FARTHER SOUTH. THERE LOOKS TO BE A
FAIRLY SHORT WINDOW OF TIME WHEN THE GREATER LIFT SLIDES NEARBY,
THEREFORE ANY SNOW ACCUMULATIONS LOOK TO BE LIMITED TO ABOUT A
POSSIBLE COATING ACROSS THE FAR NORTHERN AREAS. THE COLD CONTINUES,
ALTHOUGH NOT AS HARSH, WITH HIGH TEMPERATURES MONDAY IN THE 30S
(20S IN THE HIGHER TERRAIN), HOWEVER SOME LOW 40S IN DELMARVA TO
SOUTHEAST NEW JERSEY. IT WILL NOT BE AS COLD MONDAY NIGHT AS
PREVIOUS NIGHTS DUE TO THE WARM AIR ADVECTION REGIME AND ALSO
CLOUD COVER HANGING ON.
FOR TUESDAY, A WEAK SHORTWAVE WILL TRACK ON BY ALLOWING A WARM FRONT
TO LIFT TO OUR NORTH. THIS WILL BE THE BEGINNING OF A SHORT PATTERN
CHANGE FOR THE WEEK WHERE HIGH TEMPERATURES ARE EXPECTED TO BE
SEVERAL DEGREES ABOVE AVERAGE AND RANGING FROM THE LOW 40S TO LOW
50S (30S IN THE POCONOS AND NORTHWEST NEW JERSEY). SOME OVERRUNNING
TIED TO A NEARBY WARM FRONT MAY PRODUCE SOME LIGHT RAIN AT NIGHT,
ESPECIALLY ACROSS THE NORTHERN HALF OF THE AREA. WARMING ALOFT
COMBINED WITH SOME LINGERING COLD AIR AT THE SURFACE COULD RESULT IN
SOME POCKETS OF LIGHT FREEZING RAIN MAINLY IN THE POCONO PLATEAU TO
NEAR SUSSEX COUNTY, NJ.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
SUMMARY...A SHORT DURATION PATTERN CHANGE RESULTS IN TEMPERATURES
WELL ABOVE AVERAGE, THEN A STRONG COLD FRONT SATURDAY LOOKS TO
END THE WARM-UP.
SYNOPTIC OVERVIEW...A SHORTWAVE TROUGH ALOFT SLIDES ACROSS THE
NORTHEAST AND NORTHERN MID-ATLANTIC REGIONS WEDNESDAY. UPPER-LEVEL
RIDGING THEN DEVELOPS ACROSS THE EASTERN U.S. ON THURSDAY INTO
FRIDAY AS A STRONG UPPER-LEVEL TROUGH GRADUALLY SHIFTS INTO THE
PLAINS. THIS TROUGH WILL EVENTUALLY ARRIVE IN OUR REGION ON
SATURDAY. AT THE SURFACE, A COLD FRONT IS EXPECTED TO CROSS OUR AREA
ON WEDNESDAY, FOLLOWED BY A BRIEF AREA OF HIGH PRESSURE ON THURSDAY.
A WARM FRONT THEN MOVES NORTH ON FRIDAY WITH A STRONGER COLD FRONT
ARRIVING BY LATER SATURDAY.
FOR WEDNESDAY...A SHORTWAVE SLIDES ACROSS THE NORTHEAST. AT THE
SURFACE, LOW PRESSURE WILL BE TRACKING THROUGH THE EASTERN GREAT
LAKES AND INTO SOUTHERN QUEBEC. SOME GUIDANCE IS EVEN INDICATING A
SECONDARY LOW DEVELOPING NEAR THE VICINITY OF LONG ISLAND LIFTING
NORTHEAST TOWARD MAINE AS THE TROUGH DEEPENS. AS THE PARENT LOW
SLIDES BY TO OUR NORTH, ITS ASSOCIATED COLD FRONT CROSSES THE MID-
ATLANTIC REGION BY WEDNESDAY AFTERNOON. THE MAIN FORCING SHOULD BE
LIFTING TO OUR NORTH WEDNESDAY MORNING AND THEREFORE A LITTLE LIGHT
RAIN POSSIBLE ACROSS THE FAR NORTH TO START THE DAY. AS A COLD FRONT
MOVES ACROSS THE AREA IT APPEARS TO BE LACKING MOISTURE. HIGH
TEMPERATURES RANGE FROM THE 40S FOR NORTHERN AREAS AND LOW TO MID
50S FOR SOUTHERN AREAS (POSSIBLY 60 DEGREES IN PARTS OF DELMARVA).
FOR THURSDAY THROUGH SATURDAY...UPPER-LEVEL RIDGING OVERSPREADS THE
EASTERN U.S. WELL AHEAD OF A STRONG UPPER-LEVEL TROUGH OUT WEST. AS
THAT TROUGH GRADUALLY SHIFTS INTO THE PLAINS, HIGH PRESSURE OVER OUR
AREA ON THURSDAY SHIFTS OFFSHORE. SOME SLIGHTLY COOLER AIR SHOULD BE
WITH THIS AND ALSO IN THE WAKE OF A WEAK COLD FRONT, SO HIGH
TEMPERATURES SHOULD STILL REMAIN ABOVE AVERAGE, BUT WILL BE A FEW
DEGREES COOLER THAN WEDNESDAY. AS WARM AIR ADVECTION INCREASES, A
WARM FRONT LIFTS TO OUR NORTH DURING FRIDAY. THIS WILL RESULT IN
SOME INCREASED CLOUDINESS ALONG WITH A CHANCE FOR SHOWERS STARTING
THURSDAY NIGHT. THE MAIN SYSTEM LOOKS TO BE SLOWER TO ARRIVE, SO
DEPENDING ON HOW FAR NORTH THE DEEPER WARM SECTOR GETS, FRIDAY MAY
END UP BEING RATHER MILD ACROSS AT LEAST PARTS OF THE REGION WITH
HIGHS AROUND 60 DEGREES IN THE COASTAL PLAIN. A SIMILAR SETUP FOR
SATURDAY, AS LOW PRESSURE ARRIVES ALONG WITH A STRONG COLD FRONT. A
MILD AIR MASS REMAINS IN PLACE AHEAD OF THE FRONT SATURDAY WITH
HIGHS IN THE 50S FOR MUCH OF THE AREA (AROUND 60 POSSIBLE ACROSS THE
COASTAL PLAIN). A DECENT CHANCE OF SHOWERS CONTINUES WITH THIS
SYSTEM ARRIVING, THE IT SHOULD TREND DRIER AND COLDER SATURDAY
NIGHT.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR. WEST/NORTHWEST WINDS AROUND 10 KT. A FEW
GUSTS UP TO 20 KT POSSIBLE, THOUGH NOT EXPECTED TO BE FREQUENT
ENOUGH TO INCLUDE IN MOST OF THE TAFS. PERIODS OF MVFR CIGS FROM
STRATOCU OVER ABE THIS AFTERNOON. HIGH CONFIDENCE.
TONIGHT...VFR. WINDS BECOMING LIGHT/VARIABLE. HIGH CONFIDENCE.
OUTLOOK...
MONDAY...VFR OVERALL. SOME LIGHT SNOW POSSIBLE FOR A TIME NORTH OF
MOSTLY KABE TO KTTN.
TUESDAY AND WEDNESDAY...VFR CEILINGS, WHICH MAY LOWER TO AREAS OF
SUB-VFR WITH SOME RAIN POSSIBLE ESPECIALLY TUESDAY NIGHT.
THURSDAY...VFR.
MARINE
WINDS AND SEAS EXPECTED TO STAY BELOW SMALL CRAFT CRITERIA
THROUGH TONIGHT. NW WINDS GUSTS RAMP UP TO AROUND 20 KTS THIS
AFTERNOON BEFORE DROPPING TO 10 KTS OR LESS TONIGHT. SEAS 1-2
FEET.
OUTLOOK...
MONDAY THROUGH THURSDAY...NO MARINE HEADLINES ARE ANTICIPATED.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...GORSE
NEAR TERM...MJL/RCM
SHORT TERM...DESILVA/GORSE
LONG TERM...DESILVA/GORSE
AVIATION...GORSE/MJL/RCM
MARINE...GORSE/RCM
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