882
FXUS61 KPHI 151919
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
219 PM EST MON DEC 15 2025
SYNOPSIS
ARCTIC HIGH PRESSURE OVER THE MID-ATLANTIC SETTLES OVER THE
SOUTHEAST TUESDAY THROUGH TUESDAY NIGHT BEFORE MOVING OUT TO
SEA. A WEAK FRONT PASSES THROUGH WEDNESDAY EVENING, THEN HIGH
PRESSURE REESTABLISHES ITSELF OVER THE AREA THURSDAY. A STRONG
COLD FRONT PASSES THROUGH THE REGION THURSDAY NIGHT THROUGH
FRIDAY. ARCTIC HIGH PRESSURE RETURNS FOR THIS WEEKEND. A WEAK
COLD FRONT PASSES THROUGH SUNDAY NIGHT, FOLLOWED BY HIGH
PRESSURE ONCE AGAIN FOR MONDAY.
NEAR TERM /THROUGH TUESDAY/
AN INCREASE IN CLOUDS IN RESPONSE TO SOME UPPER LEVEL ENERGY
PASSING THROUGH THE AREA THIS AFTERNOON MAY RESULT IN SOME SNOW
SHOWERS OR FLURRIES ACROSS THE POCONOS AND LEHIGH VALLEY. ANY
SNOW SHOWERS WILL CONCLUDE BY EARLY EVENING AND ANY ACCUMULATION
WOULD BE NEGLIGIBLE. ELSEWHERE, MOSTLY CLOUDY SKIES AND DRY
WEATHER IS EXPECTED.
SURFACE HIGH PRESSURE SETTLES OFF TO OUR SOUTH TONIGHT BEFORE
GRADUALLY SHIFTING OFF THE SOUTHEAST COAST ON TUESDAY. SKIES
WILL CLEAR OUT OVERNIGHT AND WINDS WILL DIMINISH AND BECOME
LIGHT AND VARIABLE AT TIMES. ANOTHER COLD NIGHT IS EXPECTED AS
MUCH OF THE AREA SHOULD BE ABLE TO RADIATE PRETTY WELL. AS A
RESULT, LOWS SHOULD TANK AND BOTTOM OUT IN THE LOW TO MID TEENS
WITH SINGLE DIGITS IN THE HIGHER ELEVATIONS. WITH LIGHT WINDS,
WIND CHILLS WON'T BE FAR OFF FROM ACTUAL AIR TEMPERATURES
OVERNIGHT.
FOR TUESDAY, WITH THE HIGH SLOWLY SLIDING OFF THE COAST, THE
REGION WILL BEGIN TO ENCOUNTER SOUTHWESTERLY RETURN FLOW. THIS
SHOULD ALLOW TEMPERATURES TO MODERATE A BIT WHERE HIGHS WILL
MAINLY BE IN THE 30S (20S IN THE HIGHER TERRAIN). SUNNY SKIES
SHOULD PREVAIL IN THE MORNING, WITH AN INCREASE IN CLOUDS IN THE
AFTERNOON AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES LATER
IN THE DAY. NO PRECIPITATION IS EXPECTED.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
HIGH PRESSURE SETTLES OFF THE SOUTHEAST COAST TUESDAY NIGHT,
AND WHILE RETURN FLOW SETS UP, THE COMBINATION OF SKIES CLEARING
OUT ENOUGH WITH WINDS LIGHT ENOUGH AND WITH LINGERING SNOWPACK
THAT TEMPERATURES SHOULD RADIATE DOWN INTO THE TEENS AND LOW
20S.
ZONAL FLOW SETS UP ON WEDNESDAY AND A WEAK TROUGH APPROACHES
FROM THE WEST. TEMPERATURES BEGIN TO MODERATE SOMEWHAT, BUT WILL
STILL BE BELOW NORMAL LEVELS TOPPING OFF IN THE LOW TO MID 40S.
HIGH PRESSURE THEN BUILDS BACK OVER THE AREA FOR WEDNESDAY
NIGHT AND THURSDAY. STILL COLD WEDNESDAY NIGHT WITH LOWS IN THE
20S, BUT THEN HIGHS REBOUND ON THURSDAY TO ABOVE NORMAL LEVELS
IN THE UPPER 40S TO LOW 50S NORTH AND WEST OF THE FALL LINE AND
IN THE LOW TO MID 50S ACROSS THE DELAWARE VALLEY, DELMARVA, AND
SOUTHERN NEW JERSEY.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
HIGH PRESSURE MOVES OUT TO SEA THURSDAY NIGHT, AND LOW PRESSURE
PASSING THROUGH THE GREAT LAKES WILL DRAG A COLD FRONT INTO THE
REGION LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL BE
WARM ENOUGH FOR THIS TO BE A MOSTLY RAIN EVENT, THOUGH WITH COLD
AIR ADVECTION ON THE BACK SIDE OF THE SYSTEM, THERE MAY BE SOME
RAIN/SNOW MIX IN THE SOUTHERN POCONOS AND PORTIONS OF THE
LEHIGH VALLEY. THERE ARE SOME SIGNALS FOR SOME MODERATE TO
POSSIBLY EVEN HEAVY RAINFALL OVER THE AREA WITH THIS SYSTEM. THE
BULK OF THE RAIN, AT LEAST AT THIS TIME, LOOKS TO FALL BETWEEN
MIDNIGHT OR SO THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. 13Z NBM
PROBABILITY OF 24 HOUR PRECIPITATION ENDING 7 PM FRIDAY IS 70 TO
80 PERCENT FOR GREATER THAN 0.5 INCHES AND 40 TO 60 PERCENT FOR
GREATER THAN 1 INCH. LOWS THURSDAY NIGHT WILL BE IN THE UPPER
30S TO LOW 40S, AND THEN HIGHS ON FRIDAY WILL BE IN THE UPPER
40S TO LOW 50S. THIS RAINFALL SHOULD TAKE CARE OF THE BULK OF
THE SNOWPACK OVER THE AREA.
COLD FRONT PASSES THROUGH BY FRIDAY NIGHT AND THEN ARCTIC HIGH
PRESSURE BUILDS BACK INTO THE REGION WITH LOWS IN THE 20S FRIDAY
NIGHT AND THEN HIGHS IN THE UPPER 30S TO LOW 40S ON SATURDAY.
SOME STRONG SHORTWAVES WILL PASS THROUGH THE REGION WITH MINIMAL
IMPACTS.
HIGH PRESSURE SLIDES OFFSHORE SATURDAY NIGHT AND TEMPERATURES
REBOUND ON SUNDAY WITH HIGHS IN THE MID TO UPPER 40S. A WEAK
FRONT MAY PASS THROUGH THE REGION SUNDAY NIGHT AND THEN HIGH
PRESSURE RETURNS ON MONDAY WITH NEAR TO SLIGHTLY BELOW NORMAL
LEVELS.
AVIATION /19Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY (THROUGH 23Z)...VFR WITH MID-HIGH LEVEL CLOUDS.
WEST-NORTHWEST WINDS AROUND 10 KT. A SLIGHT CHANCE OF A SNOW
SHOWER AT KABE AND KRDG. HIGH CONFIDENCE.
TONIGHT...VFR. DECREASING CLOUDS. SOUTHWEST WINDS AROUND 5 KT
OR LESS, BECOMING LIGHT AND VARIABLE AT TIMES. HIGH CONFIDENCE.
TUESDAY...VFR. CLEAR SKIES IN THE MORNING, WITH INCREASING
CLOUDS IN THE AFTERNOON. WEST-NORTHWEST WINDS IN THE MORNING
AROUND 5-10 KT, SETTLE OUT OF THE WEST-SOUTHWEST IN THE
AFTERNOON. HIGH CONFIDENCE.
OUTLOOK...
TUESDAY THROUGH THURSDAY...VFR/NSW.
THURSDAY NIGHT THROUGH FRIDAY...SUB-VFR CONDS IN RA THROUGH
FRIDAY AFTERNOON. SW WINDS GUSTING 25 TO 30 KT THURSDAY NIGHT,
TURNING W-NW ON FRIDAY.
FRIDAY NIGHT THROUGH SATURDAY...VFR/NSW.
MARINE
AS OF 2:00 PM, ALL REMAINING SMALL CRAFT ADVISORIES HAVE EITHER
BEEN ALLOWED TO EXPIRE OR CANCELLED. NO FURTHER MARINE
HEADLINES ARE EXPECTED THROUGH TUESDAY.
WEST WINDS THIS AFTERNOON WILL SETTLE OUT OF THE WEST-SOUTHWEST
AROUND 15-20 KT TONIGHT WITH SEAS OF 2-4 FEET. FOR TUESDAY,
WEST-NORTHWEST WINDS AROUND 10-15 KT AND SEAS OF 1-3 FEET ARE
EXPECTED. FAIR WEATHER.
OUTLOOK...
TUESDAY NIGHT...SUB-SCA CONDITIONS.
WEDNESDAY...MARGINAL SCA CONDITIONS MAY DEVELOP WITH GUSTS UP
TO 25 KT AND SEAS BUILDING TO 5 FEET.
WEDNESDAY NIGHT THROUGH THURSDAY...SUB-SCA CONDITIONS.
THURSDAY NIGHT THROUGH FRIDAY...STRONG SCA CONDITIONS
DEVELOPING WITH GALES POSSIBLE ON FRIDAY. VSBY RESTRICTIONS IN
RAIN AND FOG.
FRIDAY NIGHT...SCA CONDITIONS.
SATURDAY...SUB-SCA CONDITIONS.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...MPS
NEAR TERM...DESILVA
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...DESILVA/MPS
MARINE...DESILVA/MPS
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