165
FXUS61 KPHI 181434
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
934 AM EST TUE FEB 18 2025
SYNOPSIS
HIGH PRESSURE BUILDS IN FROM THE WEST BEFORE SLIDING SOUTH AND
EAST OF THE REGION TUESDAY NIGHT. LOW PRESSURE APPROACHES THE
MID-ATLANTIC AND MOVES OFFSHORE WEDNESDAY THROUGH THURSDAY.
HIGH PRESSURE RETURNS FOR THE END OF THE WEEK AND THIS WEEKEND.
NEAR TERM /THROUGH TONIGHT/
FORECAST RUNNING ON TRACK. WILL MAKE ADJUSTMENTS TO HOURLY GRIDS
BASED ON THE LATEST SURFACE OBSERVATIONS. WILL GO AHEAD AND
CANCEL THE COLD WEATHER ADVISORY THAT WAS IN EFFECT UNTIL 10 AM
FOR CARBON AND MONROE COUNTIES.
OTHERWISE, THROUGH EARLY WEDNESDAY MORNING, THE MAIN STORY IS
GOING TO BE CONTINUED COLD WITH BREEZY (BUT GRADUALLY
DIMINISHING) WINDS. A SURFACE RIDGE WILL BE BUILDING EASTWARD
OVER OUR REGION AND WILL BE THE DOMINANT PATTERN FEATURE FOR OUR
AREA. THE COMBINATION OF THIS RIDGE BUILDING IN LEADING TO A
DECREASING SURFACE PRESSURE GRADIENT, AND THE LOW AND MID LEVEL
JETS FINALLY PROGRESSING EASTWARD IS WHAT WILL MAKE THE
DIFFERENCE WITH THE WINDS FINALLY DIMINISHING ESPECIALLY INTO
TONIGHT.
WE COULD ONCE AGAIN GET CLOSE TO COLD WEATHER ADVISORY IMPACTS
IN THE SOUTHERN POCONOS TUESDAY NIGHT, BUT IF WE GET CLOUDS TO
MOVE IN EARLY ENOUGH (AHEAD OF THE LOW THAT WILL BE PASSING TO
OUR SOUTH WEDNESDAY INTO THURSDAY), THEN THAT COULD LIMIT HOW
COLD AREAS GET TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AFTER A CHILLY START TO THE DAY WEDNESDAY, CLOUDS WILL START TO
FILTER IN OVER THE REGION AS HIGH PRESSURE PUSHES OFFSHORE.
ATTENTION STILL TURNS TO THE DEEPENING UPPER LEVEL CLOSED LOW AS
IT DIGS SOUTH OF THE GREAT LAKES INTO WEDNESDAY NIGHT
EVENTUALLY DEVELOPING A SURFACE LOW PRESSURE SYSTEM WELL OUT
AHEAD OF THE PARENT UPPER LEVEL THROUGH. ENSEMBLE GUIDANCE
CONTINUES TO INDICATE A SLIGHTLY SOUTHERN SHIFT IN THE CENTER OF
THE LOW TRACKS RESULTING IN THE BULK OF THE SNOW FALLING OVER
SOUTHERN PORTIONS OF DELAWARE AND THE EASTERN SHORES OF
MARYLAND, AND MINIMAL SNOW ACCUMULATIONS FOR THE MAJORITY OF THE
FORECAST AREA. THE LONE EXCEPTION TO THE REDUCED SNOW TOTALS IS
THE NAM WHICH DID SLIGHTLY SHIFT NORTH.
WITH THE SLIGHT REDUCTION IN SNOWFALL AMOUNTS HERE AT THE NEW
ANTICIPATED ACCUMULATIONS FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY:
LESS THAN AN INCH OVER THE SOUTHERN POCONOS, NORTHERN NEW JERSEY,
AND THE LEHIGH VALLEY DOWN TO THE I-95 CORRIDOR.
LESS THAN AN INCH FOR THE DELAWARE VALLEY, MOST OF SOUTHERN NEW
JERSEY AND COASTAL NEW JERSEY.
1 TO 3 INCHES FOR SOUTHERN PORTIONS OF THE EASTERN SHORES OF
MARYLAND, SOUTHERN DELAWARE, AND EXTREME SOUTHEAST NEW JERSEY.
THE 01Z/18 NBM PROBS CONTINUE TO DOWNPLAY THE POTENTIAL FOR
SIGNIFICANT SNOW TOTALS WITH ABOUT A 30-35% CHANCE OF 2" OR MORE OF
SNOW FOR THE JERSEY SHORE SOUTH OF ATLANTIC CITY, AND BETWEEN A 40-
45% CHANCE OF 2 OR MORE INCHES ACROSS SOUTHEASTERN SUSSEX COUNTY IN
DE. WITH THAT IN MIND, I'VE OPTED TO KEEP THE WATCH IN PLACE DURING
THIS MODEL CYCLE DUE TO THE POTENTIAL FOR THE GLOBAL SUITE TO
PERHAPS TAKE A MORE NORTHERN SHIFT AS SHOWN IN THE NAM. IF THAT DOES
NOT OCCUR, THEN ADVISORIES WILL BE LIKELY FOR CAPE MAY NJ AND SUSSEX
DE FOR THE 1-3" OF SNOW WITH NO OTHER HAZARDS ANTICIPATED DUE TO
SNOW.
THE LOW WILL DEPART THE REGION THURSDAY EVENING AND ANY LINGERING
SNOW IN NW FLOW STREAMERS SHOULD BE MINIMAL WITH LITTLE ADDITIONAL
ACCUMULATIONS.
LONG TERM /FRIDAY THROUGH MONDAY/
BROAD HIGH PRESSURE DEVELOPS IN THE WAKE OF THE DEPARTING SYSTEM AND
WILL DOMINATE THROUGH THE WEEKEND INTO THE BEGINNING OF THE WORK
WEEK. THIS WILL LEAD TO A MODERATING OF TEMPERATURES FROM WELL
BELOW NORMAL ON FRIDAY TO NEAR NORMAL BY MONDAY.
AVIATION /15Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH TODAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH
GUSTS UP TO 30 KNOTS.
TONIGHT...VFR, THOUGH HIGH CLOUDS WILL BE ON THE INCREASE LATE
TONIGHT. WEST-NORTHWEST WINDS WILL DIMINISH TO NEAR 10 KT BY
VERY LATE TONIGHT.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY...SUB-VFR CONDITIONS LIKELY IN SN
FOR KMIV/KACY, AND A SUB-VFR CONDITIONS POSSIBLE IN LIGHT SN
FOR THE REST OF THE TERMINALS.
THURSDAY NIGHT THROUGH SATURDAY...VFR.
MARINE
SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE THROUGH AT LEAST
THE DAY TIME TODAY, AND ARE EXPECTED TO CONTINUE THROUGH THE
EVENING FOR THE COASTAL WATERS.
AFTER MIDNIGHT TONIGHT, WE SHOULD SEE A LULL IN ELEVATED WINDS
AND SEAS ON THE AREA WATERS CONTINUING INTO THE EARLY MORNING ON
WEDNESDAY.
OUTLOOK...
WEDNESDAY THROUGH WEDNESDAY NIGHT...SUB-SCA CONDITIONS. VSBY
RESTRICTIONS IN SN POSSIBLE STARTING LATE WEDNESDAY AFTERNOON.
THURSDAY THROUGH THURSDAY NIGHT...SCA DURING THE DAY WITH POSSIBLE
GALE CONDITIONS THURSDAY NIGHT. VSBY RESTRICTIONS IN SN
THURSDAY.
FRIDAY THROUGH FRIDAY NIGHT...SCA CONDITIONS, WITH POSSIBLE
GALE CONDITIONS FOR THE WATERS ACROSS DE AND SOUTHERN NJ
FRIDAY, SUBSIDING FRIDAY NIGHT.
SATURDAY...SUB-SCA CONDITIONS.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR DEZ003-004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430-
431.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ450>455.
SYNOPSIS...MPS
NEAR TERM...JOHNSON/MPS
SHORT TERM...DEAL/MPS
LONG TERM...DEAL/MPS
AVIATION...COOPER/DEAL/JOHNSON/MPS
MARINE...DEAL/JOHNSON
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