995
FXUS61 KPHI 051839
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
139 PM EST MON JAN 5 2026
SYNOPSIS
A SERIES OF WEAK LOWS WILL TRACK BY TO OUR NORTH THROUGH THE FIRST
HALF 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 TUESDAY/
TONIGHT, DRY CONDITIONS PREVAIL, BUT SO SHOULD CLOUDS AS WARM
ADVECTION CONTINUES ALOFT. WHILE TEMPS SHOULD DROP A BIT, EXPECT A
NIGHT NOT AS COLD AS THIS MORNING, WITH LOWS BELOW BUT CLOSER TO
FREEZING IN MOST AREAS, PERHAPS STAYING ABOVE IN PARTS OF THE
DELMARVA AND ALONG THE COAST.
A SHORTWAVE TROUGH SLIDES EASTWARD FROM THE GREAT LAKES ON TUESDAY
ALONG WITH SURFACE LOW, APPROACHING THE REGION BY LATE AFTERNOON.
WITH THE WARM FRONT ALREADY WELL NORTH OF THE REGION, TEMPERATURES
WILL BE NOTABLY WARMER WITH SOUTH TO SOUTHEASTERLY FLOW ACROSS THE
FORECAST AREA. SKIES WILL REMAIN MOSTLY CLOUDY WITH MOISTURE
ADVECTION ALOFT AHEAD OF THE ADVANCING LOW. NONETHELESS, AFTERNOON
HIGHS WILL BE A FEW DEGREES ABOVE CLIMO, WITH WIDESPREAD 40S IN THE
AFTERNOON, WITH SOME LOW 50S IN DELMARVA AND UPPER 30S IN THE
POCONOS. THESE TEMPERATURES WILL LIKELY FEEL RELATIVELY MILD GIVEN
OUR RECENT STRETCH OF COLD TEMPERATURES. SOME LIGHT RAIN MAY ARRIVE
ACROSS THE POCONOS AND NORTHERN NJ BY LATE AFTERNOON AS MOISTURE
ADVECTION ALOFT RUNS INTO THE WARM FRONT AHEAD OF THE MAIN SYSTEM,
BUT THE BEST CHANCES FOR PRECIPITATION IS EXPECTED LATER IN THE
EVENING AND NIGHTTIME HOURS.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
THE NEXT IN THE SERIES OF WAVES WILL MOVE EASTWARD FROM THE LOWER
GREAT LAKES TUESDAY EVENING TOWARDS SE NEW ENGLAND BY WEDNESDAY
MORNING. WITH THIS TRACK OF THE LOW TO OUR NORTH, THIS WILL MEAN TWO
THINGS: 1) PRECIPITATION FOR OUR AREA WILL BE MINIMAL AND MAINLY
CONFINED TO THE I-78 THROUGH THE I-80 CORRIDOR AND POINTS NORTH
THROUGH OUR NORTHERN ZONES (POPS 50-60 PERCENT HERE). THE SOUTHERLY
FLOW AND WARM ADVECTION PATTERN AHEAD OF THE SYSTEM WILL MAIN THAT
THIS WILL BE A MAINLY RAIN EVENT EXCEPT IN THE HIGHER ELEVATIONS
(ROUGHLY 1500 FT AND ABOVE) OF THE SOUTHERN POCONOS AND NW NJ WHERE
SOME FREEZING RAIN COULD OCCUR TUESDAY EVENING. PRECIPITATION
AMOUNTS LOOK TO BE MINIMAL AND EVEN THESE COLDER AREAS SHOULD
SEE TEMPERATURES RISE ABOVE FREEZING OVERNIGHT CHANGING ALL
PRECIP TO JUST RAIN SHOWERS. THERE ALSO MAY BE SOME FOG AROUND
TUESDAY NIGHT BUT CONFIDENCE IS LOW ON THIS. LOWS TUESDAY NIGHT
WILL OCCUR IN THE EVENING FOR MOST PLACES DUE TO THE WAA
PATTERN AND RANGE FROM THE LOW TO MID 30S NORTH TO THE LOW TO
MID 40S SOUTH. ALSO REGARDING OUR SOUTHERN ZONES, AREAS NEAR
AND SOUTH OF PHILLY ARE LIKELY TO SEE VERY LITTLE, IF ANY,
PRECIP FROM THIS SYSTEM (POPS 20 PERCENT OR LESS).
FOR WEDNESDAY, THE DEPARTED LOW WILL MOVE NORTH AND EAST INTO THE
CANADIAN MARITIMES WHILE HIGH PRESSURE BUILDS IN TO OUR WEST OVER
THE OHIO VALLEY. THE GRADIENT BETWEEN THESE TWO FEATURES WILL RESULT
IN A GUSTY W/NW WIND (GUSTS 20 TO 30 MPH POSSIBLE). IT WILL ALSO BE
VERY MILD AS THE AIRMASS OVER US WILL BE FROM THE PACIFIC AS OPPOSED
TO THE ARCTIC. HIGHS MOSTLY IN THE 40S NORTH AND LOW TO MID 50S
SOUTH.
THE AFORMENTIONED HIGH BUILDS EASTWARD TOWARDS THE EAST COAST
WEDNESDAY NIGHT THROUGH THURSDAY. THIS WILL RESULT IN FAIR
WEATHER WITH CONTINUING MILD TEMPERATURES (TEMPERATURES ABOUT
10 DEGREES ABOVE AVERAGE FOR THIS TIME OF YEAR). THURSDAY SHOULD
ALSO FEATURE A MIX OF SUN AND CLOUDS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/
THE WEATHER PATTERN GETS MORE ACTIVE AND MORE COMPLEX FOR THE LONG
TERM PERIOD. IN 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 OVER THE PERIOD FROM 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 ON TO EASTERN
CANADA. EVENTUALLY THIS WILL HELP PUSH A COLD FRONT THROUGH THE
AREA LATE SATURDAY. 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 THOUGH, 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 SOME
SHOWERS THROUGH ALONG WITH VERY MILD TEMPERATURES. EXPECT HIGHS
GENERALLY RANGING FROM THE 50S TO LOW 60S. ADDITIONAL ROUNDS OF
RAIN/SHOWERS ARE LIKELY TO AFFECT THE AREA FRIDAY NIGHT THROUGH
SATURDAY WITH SATURDAY'S TEMPERATURES POTENTIALLY TOPPING OUT EVEN
SLIGHTLY HIGHER THAN FRIDAY. A COLD FRONT EVENTUALLY DOES COME
THROUGH FROM WEST TO EAST LATER IN THE DAY SATURDAY OR SATURDAY
NIGHT AND THIS WILL BE FOLLOWED BY BLUSTERY AND COLDER CONDITIONS
FOR SUNDAY WITH TEMPERATURES RETURNING TO MORE SEASONABLE LEVELS
THROUGH EARLY NEXT WEEK.
AVIATION /18Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS...
REST OF TODAY...MAINLY VFR WITH BKN MID-LEVEL CEILINGS. CAN'T FULLY
RULE OUT FLURRIES OR A LIGHT SNOW SHOWER IN THE AFTERNOON FOR
NORTHERN TERMINALS, BUT DRY CONDITIONS ARE EXPECTED TO PREVAIL, SO
KEPT ANY PRECIP OUT OF TAFS. SOUTH WINDS AROUND 5-10 KT. MODERATE
CONFIDENCE.
TONIGHT...VFR WITH MAINLY HIGH CLOUDS. WINDS BACK TO LIGHT AND
VARIABLE. COULD BE A BIT OF LOW LEVEL WIND SHEAR AS LOW-LEVEL JET
REMAINS STRONG FOR A FEW HOURS IN THE EVENING. MODERATE CONFIDENCE.
TUESDAY...MAINLY VFR. WINDS FROM THE E TO SE AROUND 5 KTS. FOG
POSSIBLE FOR ACY LATE AFTERNOON/EARLY EVENING DUE TO ONSHORE FLOW.
LOW STRATUS POSSIBLE INTO MIV AS WELL. HIGH CONFIDENCE IN VFR
THROUGH EARLY AFTERNOON. LOW CONFIDENCE IN FOG/LOW STRATUS
POTENTIAL.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...A PERIOD OF SUB-VFR CONDITIONS
PROBABLE MAINLY TUESDAY NIGHT (SOME FOG POSSIBLE), OTHERWISE VFR
CEILINGS. SOME LIGHT RAIN POSSIBLE TUESDAY NIGHT.
THURSDAY...VFR CEILINGS CLEAR OUT.
FRIDAY - SATURDAY...SUB-VFR CONDITIONS LIKELY WITH SHOWERS.
MARINE
WINDS AND SEAS EXPECTED TO STAY BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY. WINDS SSW 15-20 KT THIS AFTERNOON, DIMINISH TO 5-10 KT
TONIGHT, TURNING S TO SE TUESDAY. SEAS 1-2 FEET.
OUTLOOK...
TUESDAY NIGHT THROUGH SATURDAY...A PERIOD OF SMALL CRAFT ADVISORY
CONDITIONS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY, THEN AGAIN FRIDAY
THROUGH SATURDAY.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...FITZSIMMONS/GORSE
NEAR TERM...MJL
SHORT TERM...FITZSIMMONS
LONG TERM...FITZSIMMONS
AVIATION...FITZSIMMONS/MJL
MARINE...FITZSIMMONS/MJL
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