123
FXUS61 KPHI 122304
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
604 PM EST MON JAN 12 2026
WHAT HAS CHANGED
THERE IS A DRIER TREND FOR THURSDAY AND THURSDAY NIGHT. A STORM
COULD BRING SOME WINTRY PRECIPITATION LATER IN THE WEEKEND.
KEY MESSAGES
1) A STORM SYSTEM MAY BRING SOME RAIN TO WINTRY PRECIPITATION
WEDNESDAY INTO THURSDAY.
2)...A STORM COULD BRING WINTRY PRECIPITATION LATER IN THE
WEEKEND.
DISCUSSION
KEY MESSAGE 1...A STORM SYSTEM MAY BRING SOME RAIN TO WINTRY
PRECIPITATION WEDNESDAY INTO THURSDAY.
A STRONG UPPER-LEVEL TROUGH IS FORECAST TO PIVOT INTO THE EAST LATE
WEDNESDAY THROUGH LATE THURSDAY BEFORE LIFTING OUT INTO FRIDAY. THE
STRENGTH AND ORIENTATION OF THIS TROUGH WILL BE A KEY DRIVER
REGARDING SURFACE LOW PRESSURE STRENGTH AND TRACK. A POSITIVELY
TILTED UPPER-LEVEL TROUGH LASTING LONGER WILL KEEP LOW PRESSURE
WEAKER AND MORE OUT TO SEA, WHILE A NEUTRAL TO ESPECIALLY NEGATIVELY
TILTED TROUGH WILL RESULT IN A STRONGER AND WESTWARD STORM TRACK.
THE MODEL CONSENSUS AT THIS TIME POINTS MORE TOWARD A LESS IMPACTFUL
SYSTEM DUE TO THE TROUGH CLOSING OFF FARTHER NORTH AND THE TROUGH
AXIS REMAINING MORE POSITIVE TO NEUTRAL LONGER. AN INITIAL SYSTEM
TRACKS TO OUR NORTH WITH ITS COLD FRONT ARRIVING DURING WEDNESDAY.
AS THE TROUGH CONTINUES TO AMPLIFY EASTWARD, A NEW SURFACE LOW
DEVELOPS ALONG OR NEAR AN EXISTING BAROCLINIC ZONE MOSTLY OFF THE
CAROLINA COAST, HOWEVER IT LOOKS TO MAINLY MISS OUR AREA. THE
OVERALL SYNOPTIC LIFT WITH THE INITIAL SYSTEM AND COLD FRONT SHOULD
RESULT IN THE DEVELOPMENT OF A PRECIPITATION SHIELD WEDNESDAY AND
WEDNESDAY NIGHT. THIS COULD BE MORE FOCUSED INITIALLY ACROSS EASTERN
PENNSYLVANIA BEFORE PIVOTING EASTWARD WEDNESDAY NIGHT INTO EARLY
THURSDAY MORNING AS COLDER AIR WORKS IN. IF ENOUGH MOISTURE REMAINS
AS THE COLDER AIR DEEPENS, THEN RAIN WOULD CHANGE TO SOME SNOW
BEFORE ENDING FOR PARTS OF THE AREA. THERE WILL PROBABLY BE ANOTHER
AREA OF PRECIPITATION DEVELOPING OFFSHORE ASSOCIATED WITH THE
SECONDARY LOW. ONE OF THE FORECAST CHALLENGES HAS BEEN WHETHER THIS
CAN CONSOLIDATE INTO ONE MAIN STORM FOR OUR AREA AND THE OVERALL
TRENDS ARE LOOKING LESS CONDUCIVE FOR THIS. AS A RESULT, IT LOOKS
LIKE LOWER CHANCES FOR PRECIPITATION THURSDAY AND THURSDAY NIGHT AND
THE NBM GUIDANCE HAS GONE IN THIS DIRECTION. IT WILL BE MILD AHEAD
OF THIS UPPER-LEVEL TROUGH WEDNESDAY WHICH WOULD TEND TO FAVOR RAIN,
THEN COOLING TAKES PLACE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.
GIVEN THE LOW CONFIDENCE WITH THE SPECIFICS, DID NOT ADJUST FROM THE
NBM GUIDANCE. IF A DRIER TREND CONTINUES FOR THURSDAY WITH THE
PARENT LOW DEEPENING OVER NEW ENGLAND, THEN A WINDIER DAY WOULD TEND
TO RESULT ACROSS OUR REGION. MUCH COLDER AIR FOLLOWS FOR THURSDAY
THROUGH FRIDAY.
KEY MESSAGE 2...A STORM COULD BRING WINTRY PRECIPITATION LATER IN
THE WEEKEND.
FOLLOWING AN UPPER-LEVEL TROUGH IN THE PREVIOUS KEY MESSAGE, THE
UPPER-LEVEL TROUGH MAY RELOAD INTO THE EAST FOR THE WEEKEND AND
EARLY NEXT WEEK. THE DEPTH OF THE TROUGH LOOKS TO BE STRONG ON MUCH
OF THE GUIDANCE, WHICH WOULD SUPPORT SURFACE LOW PRESSURE IN THE
EAST. IT WILL ALSO KEEP THE COLD AIR IN PLACE. THIS SYSTEM, JUST
LIKE THE PREVIOUS ONE, HAS UNCERTAINTY WITH IT DUE TO WHAT HAPPENS
WITH THE TRACK OF THE SURFACE LOW. AT LEAST SOME GUIDANCE INCLUDING
ENSEMBLE MEMBERS INDICATE SOME WINTRY PRECIPITATION POTENTIAL MOSTLY
LATER IN THE WEEKEND. WE WILL HAVE TO SEE HOW THIS ALL EVOLVES OVER
THE NEXT SEVERAL DAYS REGARDING THE DETAILS INCLUDING THE TIMING.
THE CURRENT FORECAST IS THE NBM GUIDANCE, WITH HAS UP TO 30 PERCENT
POPS ON SUNDAY.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS...
TONIGHT...VFR. CLEAR SKIES. LIGHT WEST TO SOUTHWEST WINDS AROUND
5 KNOTS. HIGH CONFIDENCE.
TUESDAY...VFR. MOSTLY CLEAR SKIES. SOUTHWEST WINDS AROUND 10 TO
12 KNOTS DEVELOPING BY AFTERNOON WITH SOME GUSTS OF AROUND 15
TO 20 KNOTS POSSIBLE. HIGH CONFIDENCE.
OUTLOOK...
TUESDAY NIGHT...VFR.
WEDNESDAY AND THURSDAY...A PERIOD OF SUB-VFR CONDITIONS DUE TO LOW
CEILINGS AND SOME RAIN AND/OR SNOW. GUSTY WEST-NORTHWEST WINDS MAY
DEVELOP DURING THURSDAY.
FRIDAY AND SATURDAY...VFR OVERALL.
MARINE
WINDS AND SEAS CONTINUE TO DIMINISH AS A RIDGE OF HIGH PRESSURE
BUILDS ACROSS THE WATERS. SUB-SCA CONDITIONS WILL REMAIN INTO
TONIGHT AND MUCH OF TUESDAY. LATER TUESDAY, AS THE RIDGE MOVES AWAY
AND LOW PRESSURE MOVES ACROSS SOUTHERN CANADA, AN INCREASING
PRESSURE GRADIENT WILL RESULT IN INCREASING WINDS. SOUTH TO
SOUTHWEST WINDS 10 TO 15 KTS WITH GUSTS TO 20 KNOTS ARE EXPECTED BY
SUNSET. FAIR WEATHER TONIGHT AND TUESDAY.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...SOUTHERLY FLOW INCREASES AND A PERIOD
OF SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE, MAINLY TUESDAY
NIGHT.
THURSDAY...SMALL CRAFT ADVISORY CONDITIONS PROBABLE, AND A PERIOD OF
GALE FORCE WIND GUSTS POSSIBLE.
FRIDAY AND SATURDAY...THE CONDITIONS MAY BE MOSTLY BELOW SMALL CRAFT
ADVISORY CRITERIA.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...GORSE
AVIATION...FITZSIMMONS/GORSE/OHARA
MARINE...GORSE/OHARA
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