460
FXUS61 KPHI 061115
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
615 AM EST TUE JAN 6 2026
SYNOPSIS
A SERIES OF WEAK LOWS WILL TRACK BY TO OUR NORTH THROUGH THE
MIDDLE OF THE WEEK. HIGH PRESSURE BUILDS IN FOR THURSDAY, THEN
LOW PRESSURE TRACKS TO OUR NORTHWEST FRIDAY AND SATURDAY WITH
ITS STRONG COLD FRONT CROSSING OUR AREA LATER SATURDAY.
NEAR TERM /THROUGH TONIGHT/
TODAY WE'LL MOSTLY BE IN BETWEEN SYSTEMS, BUT THEY ARE SO CLOSE
AND WARM ADVECTION ALOFT WILL BE CONTINUING, SO EXPECT CLOUDS TO
DOMINATE. HAD ENOUGH CLEARING EARLY THIS MORNING TO GET MOST
PLACES DOWN BELOW FREEZING, BUT WARMER SOUTH TO SOUTHWEST FLOW
SHOULD BE ENOUGH TO ELEVATE MOST AREAS ABOVE FREEZING AGAIN
DESPITE CLOUDS, IN FACT LIKELY 40S FOR AREAS NEAR/SOUTH OF I-78,
WITH 50S DOWN IN SOUTHERN DELAWARE AND THE EASTERN SHORE.
NEXT SYSTEM APPROACHES WITH WARM FRONT THIS EVENING WITH LOW
CLOUDS, FOG, MIST AND DRIZZLE LIKELY OVERSPREADING MOST OF THE
REGION. TEMPS MAY DIP BACK BELOW FREEZING ACROSS NORTHERNMOST
ZONES (ESPECIALLY MONROE COUNTY AND HIGHER ELEVATIONS OF SUSSEX
COUNTY NJ). FOR NOW HAVE HELD OFF ON A WINTER WEATHER ADVISORY
BUT ONE MAY BE NEEDED FOR LIGHT FREEZING RAIN TONIGHT. ELSEWHERE
TEMPS STAY ABOVE FREEZING, BUT FOG ADVISORIES LOOK LIKELY
ESPECIALLY FROM PHILLY AREA NORTHWARD. WARM FRONT TRIES TO PUSH
NORTHWARD LATER TONIGHT WHICH MAY BREAK THE FOG UP FROM SOUTH TO
NORTH TOWARD DAWN, BUT UNCERTAINTY ON THIS IS HIGH. TEMPS LIKELY
FAIRLY STEADY AND PERHAPS SLOWLY RISING OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
WE TRANSITION TOWARDS MORE FAIR WEATHER FOR MUCH OF THE SHORT
TERM PERIOD AS OUR LOW PRESSURE SYSTEM MOVES NORTHEAST TOWARDS
THE CANADIAN MARITIMES AND A HIGH PRESSURE SYSTEM BUILDS IN FROM
THE OHIO VALLEY ON WEDNESDAY. ANY LINGERING PRECIPITATION EARLY
WEDNESDAY MORNING WILL TAPER OFF AS THE HIGH BUILDS IN AND
CLOUDS DECREASE. THE PRESSURE GRADIENT BETWEEN THE DEPARTING LOW
AND THE HIGH PRESSURE SYSTEM BUILDING IN WILL RESULT IN AN
INCREASE IN WINDS WEDNESDAY. WIND GUSTS WILL RANGE FROM 20-30
MPH WITH PERHAPS UPWARDS OF 35 MPH IN THE POCONOS. THESE WINDS
WILL DECREASE BY WEDNESDAY EVENING AS THE PRESSURE GRADIENT
LESSENS. HIGH TEMPERATURES ON WEDNESDAY ARE IN THE 40S AND 50S
ACROSS THE AREA.
OUR HIGH PRESSURE SYSTEM MOVES OVERHEAD WEDNESDAY NIGHT AND
SHIFTS OFFSHORE THURSDAY. THIS KEEPS US DRY WEDNESDAY NIGHT WITH
A MOSTLY CLEAR SKY. LOWS ARE MAINLY IN THE 30S. BY THURSDAY, WE
START TO SEE MORE CLOUDS FILTER IN THROUGHOUT THE DAY AHEAD OF
OUR NEXT SYSTEM AS THE HIGH PRESSURE SYSTEM DEPARTS. HIGHS ON
THURSDAY ARE ONCE AGAIN MILD WITH TEMPERATURES IN THE 40S AND
50S.
LONG TERM /FRIDAY THROUGH MONDAY/
THE WEATHER PATTERN GETS MORE ACTIVE AND COMPLEX FOR THE LONG
TERM PERIOD. LOOKING AT THE BIG PICTURE, THERE WILL BE A LARGE
UPPER LEVEL LONG WAVE TROUGH THAT WILL BE MOVING EASTWARD FROM
THE ROCKY MOUNTAINS TOWARDS THE EAST COAST DURING THE TIME
PERIOD OF THURSDAY NIGHT THROUGH THE WEEKEND. AS THIS OCCURS,
THERE WILL BE MULTIPLE SHORTWAVES PIVOTING THROUGH THE BASE OF
THE TROUGH. THIS WILL LEAD TO ONE OR MORE AREAS OF SURFACE LOW
PRESSURE DEVELOPING AND MOVING NORTHWARD TOWARDS THE GREAT LAKES
AND THEN EASTERN CANADA. EVENTUALLY THIS WILL HELP PUSH A COLD
FRONT THROUGH THE AREA SATURDAY NIGHT. THE MAIN AREA OF
UNCERTAINTY IS WHETHER THERE WILL BE ONE LARGE AND RELATIVELY
DEEP LOW OR SEVERAL WEAKER WAVES THAT MOVE NORTH ALONG THE
BAROCLINIC ZONE. EITHER WAY, THIS LOOKS TO RESULT IN VERY MILD
BUT UNSETTLED WEATHER FRIDAY THROUGH THE FIRST HALF OF THE
WEEKEND.
IN TERMS OF THE DETAILS, A WARM FRONT WILL LIFT NORTHWARD
THROUGH THE AREA FRIDAY BRINGING AN INITIAL ROUND OF SHOWERS
ALONG WITH VERY MILD TEMPERATURES. HIGHS LOOK TO RANGE FROM THE
MID 50S TO MID 60S. ADDITIONAL ROUNDS OF RAIN/SHOWERS ARE LIKELY
TO MOVE THROUGH THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT.
HIGH TEMPERATURES ON SATURDAY WILL BE SIMILAR TO FRIDAY'S
TEMPERATURES. A COLD FRONT LOOKS TO MOVE THROUGH FROM WEST TO
EAST SATURDAY NIGHT WHICH WILL BE FOLLOWED BY BLUSTERY AND
COLDER CONDITIONS ON SUNDAY. TEMPERATURES RETURN TO MORE
SEASONABLE LEVELS EARLY NEXT WEEK AND WE TREND DRIER AS A HIGH
PRESSURE SYSTEM BUILDS IN.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS...
TODAY...MAINLY VFR UNTIL VERY LATE WHEN CONDITIONS RAPIDLY
DECREASE WITH LOW STRATUS DECK AND/OR FOG AND LIGHT
RAIN/DRIZZLE. EAST-SOUTHEAST WINDS AROUND 5-10 KT. HIGH
CONFIDENCE THROUGH MID-AFTERNOON, BUT LOW CONFIDENCE IN FOG/LOW
STRATUS LATE.
TONIGHT...IFR ALL TERMINALS, WITH LIFR TO VLIFR LIKELY, ESP
NORTHERN TERMINALS LIKE KABE, DUE TO LOW CIGS AND FOG ALONG WITH
LIGHT RAIN/DRIZZLE. WINDS LIGHT/VARIABLE UNTIL LATE, THEN WARM
FRONT LIFTS NORTH TOWARD DAWN WITH WINDS BECOMING S TO SW 5-10
KT. LOW LEVEL WIND SHEAR OF 40 KT ALSO LIKELY. MODERATE
CONFIDENCE OVERALL, LOW CONFIDENCE IN DETAILS.
OUTLOOK...
WEDNESDAY...A PERIOD OF SUB-VFR CONDITIONS POSSIBLE EARLY,
OTHERWISE VFR CEILINGS. INCREASING WEST-NORTHWEST WINDS
WITH GUSTS UPWARDS OF 20-25 KT. WINDS DECREASE IN THE EVENING.
THURSDAY...VFR. NO SIGNIFICANT WEATHER EXPECTED.
FRIDAY THROUGH SATURDAY...SUB-VFR CONDITIONS LIKELY WITH
SHOWERS.
MARINE
WINDS AND SEAS EXPECTED TO STAY BELOW SMALL CRAFT CRITERIA
THROUGH TONIGHT. WINDS SSE 5-10 KT TODAY, INCREASING TO 10-15 KT
TONIGHT. SEAS 1-2 FEET TODAY, INCREASING TO 3-4 FEET TONIGHT.
PATCHY DENSE MARINE FOG POSSIBLE THIS AFTERNOON AND TONIGHT.
OUTLOOK...
WEDNESDAY...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL OF
THE ATLANTIC COASTAL WATERS FOR SEAS OF 4-6 FEET AND WIND GUSTS
OF 25 KT.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA.
FRIDAY THROUGH SATURDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 10 PM EST WEDNESDAY FOR
ANZ450>452.
SMALL CRAFT ADVISORY FROM 6 AM TO 7 PM EST WEDNESDAY FOR
ANZ453>455.
SYNOPSIS...GUZZO/RCM
NEAR TERM...RCM
SHORT TERM...GUZZO
LONG TERM...FITZSIMMONS/GUZZO
AVIATION...GUZZO/RCM
MARINE...GUZZO/RCM
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