216
FXUS61 KPHI 010540
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1240 AM EST MON DEC 1 2025
SYNOPSIS
A LOW PRESSURE SYSTEM AND ITS ASSOCIATED COLD FRONT CONTINUE TO
APPROACH THE REGION, WITH THE COLD FRONT PASSING THROUGH
TONIGHT. LOW PRESSURE WILL DEVELOP OVER THE SOUTHEAST MONDAY
NIGHT BEFORE TRACKING NORTHEAST TOWARDS OUR AREA TUESDAY INTO
TUESDAY NIGHT. ANOTHER COLD FRONT WILL TRACK THROUGH THE REGION
THURSDAY NIGHT, WITH HIGH PRESSURE BUILDING BACK IN THEREAFTER.
ANOTHER SYSTEM MAY IMPACT THE REGION FRIDAY NIGHT INTO THE
WEEKEND.
NEAR TERM /THROUGH TODAY/
A MID-LEVEL SHORTWAVE AXIS EMBEDDED IN A LARGER SCALE TROUGH IS
CURRENTLY PIVOTING NORTHEASTWARD INTO PORTIONS OF FAR SOUTHERN
ONTARIO AND QUEBEC. THE TROUGH WILL DEPART TO THE NORTHEAST
TONIGHT, WITH SUBTLE HEIGHT RISES THROUGH MONDAY AS A SUBTLE
RIDGE AXIS SHIFTS THROUGH THE AREA AHEAD OF THE NEXT MAJOR
TROUGH. AT THE SURFACE, THE COLD FRONT THAT HAS BEEN MOVING
THROUGH THE REGION IS NOW CLEARING THE AREA AND MOVING OFFSHORE.
HIGH PRESSURE WILL BEGIN TO BUILD IN BEHIND FROM THE OHIO
VALLEY REGION AND REMAIN IN PLACE THROUGH MONDAY EVENING.
TONIGHT, CLOUDS WILL CLEAR WITH THE PASSAGE OF THE COLD FRONT.
THERE MAY BE A BRIEF LULL IN THE WIND DURING THE EARLY HOURS OF
THE NIGHT, BUT AS THE COLD FRONT MOVES THROUGH IT WILL AGAIN GET
BREEZY OUT OF THE NORTHWEST, WITH GUSTS TO 20 MPH TO PERHAPS 30
MPH. WITH STRONG COLD AIR ADVECTION TAKING PLACE, LOWS TONIGHT
WILL BE IN THE UPPER 20S TO NEAR 30 DEGREES ACROSS THE ENTIRE
AREA.
MONDAY SHOULD START MOSTLY CLEAR, WITH SOME INCREASE IN HIGH CLOUDS
DURING THE AFTERNOON HOURS. GUSTY NORTHWEST WINDS IN THE
MORNING WILL DIMINISH BY THE AFTERNOON AS THE HIGH MOVES
OVERHEAD AND THE PRESSURE GRADIENT RELAXES. HIGH TEMPERATURES
WILL BE NEAR FREEZING IN THE POCONOS, IN THE UPPER 30S TO LOWER
40S FOR EASTERN PA AND MUCH OF NJ, AND MID 40S FOR THE DELMARVA
INTO FAR SOUTHERN NJ.
SHORT TERM /TONIGHT THROUGH WEDNESDAY/
THE MAIN STORY FOR THE SHORT TERM WILL BE THE STRENGTHENING LOW
PRESSURE SYSTEM MOVING NORTHEAST MONDAY NIGHT AND OFF THE COAST INTO
TUESDAY, WHICH WILL BRING WIDESPREAD PRECIPITATION TO THE REGION.
THERE WILL BE A LOW DEVELOPING OVER THE SOUTHEASTERN US AND OUR HIGH
PRESSURE SYSTEM WILL RETREAT OFF TO THE NORTHEAST MONDAY NIGHT. THIS
LOW WILL MAKE ITS CLOSEST APPROACH TO THE AREA TUESDAY AFTERNOON,
AND BEGIN DEPARTING TO THE NORTHEAST BY TUESDAY NIGHT.
IN TERMS OF THE DETAILS WITH THIS SYSTEM, NO SIGNIFICANT CHANGES
HAVE BEEN MADE TO THE FORECAST OR MESSAGING FOR TUESDAY.
THERE ARE CHANCE TO LIKELY POPS (50-70%) STARTING MONDAY NIGHT, WITH
THE HIGHEST POPS (90-100%) BEING DURING THE DAYTIME TUESDAY. THERE
HAS BEEN A TREND TOWARD A SOMEWHAT FASTER SOLUTION IN THE
DETERMINISTIC GUIDANCE, HENCE THE SLIGHT INCREASE IN POPS IN THE
PREDAWN HOURS TUESDAY MORNING. IF THIS TREND HOLDS, IT COULD HAVE
IMPLICATIONS ON INITIAL PRECIP TYPE INTO THE I-95 CORRIDOR. THE
PRECIPITATION WILL END FROM WEST TO EAST PRETTY QUICKLY BY TUESDAY
EVENING INTO TUESDAY NIGHT AS THE LOW MOVES OFF TO THE NORTHEAST.
FOR THE PRECIPITATION ACCUMULATION, QPF HAS REMAINED FAIRLY STEADY
AROUND 0.75-1.25" ACROSS THE BOARD, GREATEST ACROSS THE COASTAL
PLAIN AND LEAST FARTHER INLAND NORTH OF I-78. DUE TO THE EARLIER
TREND IN PRECIP ONSET, THERE IS THE POTENTIAL FOR LIGHT SNOW
INITIALLY FOR MUCH OF THE AREA, AS FAR SOUTH AS NORTHEASTERN
MARYLAND, CENTRAL AND NORTHERN DELAWARE, AND PORTIONS OF INTERIOR
SOUTHERN NEW JERSEY. THIS INITIAL LIGHT SNOW COULD RESULT IN MINIMAL
ACCUMULATION (A DUSTING LESS THAN 1"), AND WOULD NOT LAST LONG AS
THE LOW DRAWS CLOSER TO THE AREA CHANGING THE PRECIP TO RAIN. AGAIN,
ANY SNOWFALL OCCURING THIS FAR SOUTH WILL BE DEPENDENT ON EXACTLY
HOW QUICKLY THE PRECIP MOVES INTO THE AREA. A SLOWER ONSET WOULD
PROBABLY MEAN MOSTLY ALL RAIN SOUTHEAST OF I-95.
THROUGH THE DAY TUESDAY, THE ONSHORE FLOW AND WARM MARINE INFLUENCE
WILL IMPACT THE TEMPERATURE PROFILES. BY DAYBREAK TUESDAY, THE
RAIN/SNOW LINE SHOULD BE NEAR OR PERHAPS JUST NW OF THE I-95
CORRIDOR. AS THE WARMER AIR CONTINUES TO FILTER IN, THE RAIN/SNOW
LINE MAY GET AS FAR NW AS I-78 AND NORTHWESTERN NEW JERSEY BY
TUESDAY AFTERNOON. FOR PERSPECTIVE ON THIS, THE TEMPERATURES FOR
HIGHS ON TUESDAY ARE NEAR FREEZING IN THE POCONOS, UPPER 30S
NORTHWEST OF THE FALL LINE, NEAR 40 DEGREES ALONG THE I-95 CORRIDOR,
AND IN THE MID 40S TO NEAR 50 IN DELMARVA AND ALONG THE COASTAL
AREAS. ALTHOUGH AREAS MAY START AS SNOW, IT DOES NOT APPEAR THAT IT
WILL LAST FOR MUCH OF THE AREA. RIGHT NOW, THE POCONOS HAVE THE BEST
POTENTIAL AT AN ALL SNOW EVENT FROM THIS SYSTEM.
AS FOR SNOWFALL ACCUMULATION, THE POTENTIAL CONTINUES TO INCREASE
FOR PLOWABLE SNOW (2" OR MORE) IN THE POCONOS AND AREAS ALONG AND
NORTH OF I-78. AS YOU HEAD WELL SOUTH AND EAST OF I-78, THE
POTENTIAL FOR PLOWABLE SNOW QUICKLY DECREASES. OUR LATEST FORECAST
INCLUDES SNOWFALL AMOUNTS LESS THAN 1" FOR THE IMMEDIATE I-95
CORRIDOR, 1-3" FOR AREAS JUST NORTHWEST OF THERE, AND IN THE 3-5"
RANGE FOR THE I-78 CORRIDOR AND NW NJ. HIGHER ELEVATIONS (ESPECIALLY
1,500 FEET AND HIGHER) IN NW NJ AND ACROSS THE POCONO PLATEAU HAVE
POTENTIAL FOR SNOWFALL IN THE 4-8" RANGE. DUE TO INCREASING
CONFIDENCE OF WARNING LEVEL SNOW (6 INCHES OR MORE) IN THE POCONOS
AND IN SUSSEX COUNTY NJ, WE HAVE ISSUED A WINTER STORM WATCH FOR
CARBON AND MONROE COUNTIES IN PA AND SUSSEX COUNTY IN NJ FROM LATE
MONDAY NIGHT INTO TUESDAY EVENING.
OUTSIDE OF MAINLY THE POCONOS AND PERHAPS THE HIGHER ELEVATIONS IN
NW NJ, THE SNOW THAT FALLS WILL THEN BE MELTING THROUGH THE DAY WITH
THE CHANGE TO ALL RAIN AND WARM AIR MOVING FURTHER INLAND. DURING
THE TRANSITION PERIOD FROM SNOW TO RAIN, SOME SLEET IS POSSIBLE
BRIEFLY. IN TERMS OF FREEZING RAIN, THE OVERALL THREAT LOOKS MINIMAL
GIVEN THE CURRENT SET UP. THE AREAS THAT SEE ALL RAIN OR A CHANGE TO
RAIN WILL HAVE A GOOD SOAKING ALL-DAY TYPE OF RAIN. A FEW
PRECIPITATION AND/OR SNOWFALL RECORDS COULD BE CHALLENGED. SEE THE
CLIMATE SECTION BELOW FOR MORE DETAILS ON THE RECORDS.
ONCE THE LOW DEPARTS TUESDAY NIGHT, A HIGH PRESSURE SYSTEM WILL
BUILD IN FROM THE SOUTHWEST. THIS WILL LEAD TO DRIER CONDITIONS
THROUGH TUESDAY NIGHT. LOWS TUESDAY NIGHT ARE IN THE 20S FOR MOST,
WHICH MAY LEAD TO SOME BLACK ICE ISSUES WHERE ANY SLUSHY SNOW MELT
REFREEZES ON ROADWAYS (ESPECIALLY NEAR AND NORTH OF I-78).
FOR WEDNESDAY, THE HIGH PRESSURE SYSTEM IS IN PLACE WHICH KEEPS US
DRY. IT IS ALSO A COLDER DAY WITH HIGHS IN THE MID 30S TO LOW
40S.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
IN THE LONG TERM PERIOD, WE STAY ACTIVE WITH OUR WEATHER PATTERN. A
COLD FRONT LOOKS TO CROSS THE AREA THURSDAY INTO THURSDAY NIGHT. AS
THE COLD FRONT PASSES THROUGH, THERE IS THE POTENTIAL FOR SOME SNOW
SHOWERS, ESPECIALLY NEAR/NORTH OF I-78. THE MAIN FACTOR WITH THIS
COLD FRONT WILL BE THE NOTABLY COLDER AIRMASS IN ITS WAKE. THURSDAY
NIGHT LOOKS INCREASINGLY LIKELY TO BE THE COLDEST NIGHT SO FAR THIS
SEASON, WITH WIDESPREAD LOW TEMPERATURES IN THE TEENS FOR MOST, AND
EVEN SINGLE DIGITS FOR THE HIGHER TERRAIN. WIND CHILL VALUES
THURSDAY NIGHT WILL BE IN THE SINGLE DIGITS TO TEENS. BY FRIDAY,
HIGHS ARE IN THE UPPER 20S TO UPPER 30S FOR MOST AREAS. BEYOND THAT,
OUR NEXT SYSTEM LOOKS TO ARRIVE LATE FRIDAY INTO THE WEEKEND,
BRINGING POTENTIAL FOR ANOTHER ROUND OF WIDESPREAD PRECIPITATION,
INCLUDING WINTRY PRECIPITATION. HOWEVER, DETAILS ON THIS SYSTEM
REMAIN VERY UNCLEAR AT THE MOMENT.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...VFR. WEST-NORTHWEST WINDS BEHIND A COLD FRONT AROUND
10-15 KT WITH GUSTS UPWARDS OF 20-25 KT OVERNIGHT. MODERATE-HIGH
CONFIDENCE.
MONDAY...VFR WITH AN INCREASE IN HIGH CLOUDS LATE IN THE DAY.
NORTHWEST WINDS AROUND 10 KT WITH GUSTS UP TO 20 KT IN THE
MORNING, BEFORE DIMINISHING TO AROUND 5-10 KT IN THE AFTERNOON.
HIGH CONFIDENCE.
OUTLOOK...
MONDAY NIGHT...PRIMARILY VFR. CHANCE (40-60%) OF SUB-VFR
CONDITIONS IN RAIN OR SNOW LATE MONDAY NIGHT.
TUESDAY THROUGH TUESDAY NIGHT...RESTRICTIONS EXPECTED IN LOW
CLOUDS AND PRECIPITATION. SNOW CHANGING TO RAIN AT RDG/ABE. FOR
THE I-95 TERMINALS, PRECIPITATION MAY BEGIN AS SNOW FOR A
COUPLE HOURS BEFORE A CHANGE TO RAIN. ALL RAIN FOR MIV/ACY.
CONDITIONS SHOULD IMPROVE BY LATE TUESDAY NIGHT, THOUGH GUSTY NW
WINDS WILL BE POSSIBLE.
WEDNESDAY...VFR. NO SIGNIFICANT WEATHER.
THURSDAY...MAINLY VFR. GUSTY WNW WINDS POSSIBLE.
FRIDAY...MAINLY VFR FOR FRIDAY. RESTRICTIONS POSSIBLE HEADING
TOWARDS FRIDAY NIGHT WITH A CHANCE (40-60%) OF RAIN/SNOW.
MARINE
A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE DELAWARE BAY UNTIL 6
AM MONDAY AND FOR THE ATLANTIC COASTAL WATERS UNTIL 9 AM MONDAY.
OVERNIGHT, WINDS WILL BECOME NORTHWESTERLY AROUND 20-25 KT WITH
FREQUENT GUSTS NEAR 30 KT FOR ALL OCEAN ZONES AND THE DELAWARE
BAY. SEAS OVER THE OCEAN SHOULD BE AROUND 5 FEET TO START THE
NIGHT, DECREASING TO AROUND 4 FEET BY SUNRISE.
WIND WILL THEN BEGIN TO DIMINISH BY MONDAY MORNING, FALLING
BELOW 25 KT AND WITH SEAS LESS THAN 5 FEET.
OUTLOOK...
MONDAY NIGHT...NO MARINE HAZARDS ANTICIPATED. FAIR WEATHER.
TUESDAY THROUGH WEDNESDAY...SCA CONDITIONS LIKELY WITH EAST
WINDS INCREASING TO NEAR 25-30 KTS AND THEN BECOMING NORTHWEST
TUESDAY NIGHT INTO WEDNESDAY. THE POTENTIAL FOR WIND GUSTS NEAR
35 KNOTS HAS INCREASED, SO A GALE WATCH WAS ISSUED FOR THE OCEAN
ZONES TUESDAY NIGHT. WINDS LOOK TO DIMINISH THROUGH THE DAY
WEDNESDAY. SEAS 5-7 FEET, ALSO DIMINISHING THROUGH THE DAY
WEDNESDAY.
THURSDAY THROUGH THURSDAY NIGHT...SCA CONDITIONS LIKELY
THURSDAY AFTERNOON INTO EARLY THURSDAY NIGHT AS NW WINDS
INCREASE TO NEAR 25-30 KTS AND SEAS 4-6 FEET.
FRIDAY THROUGH FRIDAY NIGHT...NO MARINE HAZARDS ANTICIPATED.
CLIMATE
WIDESPREAD MODERATE TO HEAVY PRECIPITATION IS EXPECTED ON
TUESDAY, DECEMBER 2ND. A FEW DAILY PRECIPITATION AND/OR SNOWFALL
RECORDS COULD BE CHALLENGED. RECORDS FOR OUR CLIMATE SITES ARE
LISTED BELOW:
RECORD PRECIPITATION (RAINFALL)
DECEMBER 2
SITE RECORD/YEAR
ALLENTOWN (ABE) 0.86"/1934
AC AIRPORT (ACY) 1.03"/1996
AC MARINA (55N) 1.18"/1929
GEORGETOWN (GED) 1.11"/1974
MOUNT POCONO (MPO) 3.56"/1996
PHILADELPHIA (PHL) 1.48"/1986
READING (RDG) 1.29"/1981
TRENTON (TTN) 2.13"/1986
WILMINGTON (ILG) 1.27"/1991
RECORD SNOWFALL
DECEMBER 2
SITE RECORD/YEAR
ALLENTOWN (ABE) 3.6"/1952
AC AIRPORT (ACY) T/2019*
PHILADELPHIA (PHL) 2.0"/1903
READING (RDG) 6.0"/1929
TRENTON (TTN) 3.0"/1903
WILMINGTON (ILG) 1.0"/1952
*MULTIPLE YEARS WITH A TRACE.
PHI WATCHES/WARNINGS/ADVISORIES
PA...WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ054-055.
NJ...WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
ANZ450>455.
GALE WATCH FROM TUESDAY AFTERNOON THROUGH LATE TUESDAY NIGHT
FOR ANZ450>455.
SYNOPSIS...GUZZO/STAARMANN
NEAR TERM...AKL/COOPER/DESILVA
SHORT TERM...GUZZO/STAARMANN
LONG TERM...GUZZO/STAARMANN
AVIATION...AKL/COOPER/DESILVA/GUZZO
MARINE...COOPER/DESILVA/GUZZO
CLIMATE...WFO PHI
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