545
FXUS61 KPHI 281908
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
308 PM EDT MON APR 28 2025
SYNOPSIS
HIGH PRESSURE WILL SETTLE OFFSHORE OVERNIGHT. A WARM FRONT
ARRIVES ON TUESDAY, FOLLOWED BY A COLD FRONT BY WEDNESDAY. HIGH
PRESSURE BRIEFLY RETURNS FOR WEDNESDAY NIGHT INTO THURSDAY.
ANOTHER LOW PRESSURE SYSTEM TRACKS TO OUR NORTH ON FRIDAY WITH A
COLD FRONT MOVING THROUGH BY EARLY SATURDAY. HIGH PRESSURE THEN
BUILDS IN BY SUNDAY.
NEAR TERM /THROUGH TUESDAY/
HIGH PRESSURE OVER THE MID-ATLANTIC WILL SLIDE OFF THE
SOUTHEAST COAST TONIGHT AND WILL REMAIN IN PLACE THROUGH
TUESDAY. A WEAK WARM FRONT WILL LIFT NORTH THROUGH THE REGION
TONIGHT. LOW PRESSURE WILL TRACK ACROSS SOUTHERN CANADA, AND
THIS WILL DRAG A COLD FRONT TOWARDS THE REGION LATE IN THE DAY.
A SEA BREEZE CONTINUES TO TRACK WEST INTO NEW JERSEY, OVERALL,
SOUTHWEST WINDS WILL RANGE FROM 5 TO 10 MPH, BUT BEHIND THE SEA
BREEZE, WINDS WILL TURN SOUTH TO SOUTHEAST. WINDS BECOME SOUTH
AROUND 5 MPH TONIGHT. A WARMER NIGHT ON TAP FOR THE AREA WITH
LOWS IN THE 40S TO LOW 50S.
WARM AIR ADVECTION WILL BE UNDERWAY ON TUESDAY WITH
TEMPERATURES WELL ABOVE NORMAL LEVELS WITH HIGHS IN THE UPPER
70S TO LOW 80S, THOUGH COOLER AT THE COASTS. AS THE
AFOREMENTIONED COLD FRONT APPROACHES, THE PRESSURE GRADIENT WILL
TIGHTEN BETWEEN THAT APPROACHING FRONT AND HIGH PRESSURE OFF
THE SOUTHEAST COAST. SOUTHWEST WINDS WILL INCREASE TO 15 TO 20
MPH WITH 25 TO 30 MPH GUSTS.
ANY SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THAT APPROACHING
FRONT SHOULD HOLD OFF UNTIL TUESDAY EVENING.
SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/
SHOWERS AND STORMS ASSOCIATED WITH APPROACHING COLD FRONT WILL
LIKELY BE DECAYING AS THEY MOVE INTO THE REGION DURING THE NIGHT
TUESDAY. HAVE HIGH CHANCE POPS FOR FURTHEST REACHES OF THE
POCONOS, RAMPING DOWN QUICKLY TO SLIGHT CHANCE ALONG I-95.
LATEST OUTLOOK AT TIME OF WRITING PLACES POCONOS IN A MARGINAL
RISK FOR SEVERE WEATHER FROM ANY DYING STRONGER STORMS WHICH
MAKE IT IN, PERHAPS HELPED ALONG BY HIGHER DCAPE SINCE LOW
LEVELS WILL BE A LITTLE DRY. LOWS WILL BE IN THE 50S IN THE
HIGHER ELEVATIONS AND AT THE COAST, BUT THE LOW TO MID 60S
ELSEWHERE THANKS TO SOUTHERLY FLOW AND CLOUDS JUST AHEAD OF THE
FRONT.
FRONT SLIDES SOUTH ACROSS THE REGION DURING THE MORNING AND
MIDDAY WEDNESDAY. THE PROGRESS LOOKS A LITTLE SLOWER, SO TEMPS
WILL BE NOTICEABLY COOLER IN THE POCONOS (60S) BUT ONLY SLIGHTLY
COOLER ACROSS I-95 (NEAR 80 DEGREES), AND DELMARVA/FAR S NJ
ACTUALLY LOOKS A BIT WARMER, HELPED ALONG BY AN OFFSHORE FLOW
BEHIND THE FRONT BEFORE COLD ADVECTION REALLY GETS GOING. RISK
OF CONVECTION ACROSS OUR SOUTHERN ZONES WITH THE FRONT LOOKS
MINIMAL, SO JUST HAVE SOME SLIGHT CHANCE POPS IN CENTRAL
DELMARVA.
HIGH PRESSURE IS MORE PROMINENT IN THE FORECAST FOR WEDNESDAY
NIGHT, WITH ENOUGH CLEARING, DRIER AIR AND RADIATIONAL COOLING
TO MAKE IT NOTICEABLY COOLER THAN TUESDAY NIGHT ACROSS THE
BOARD. LOWS MOSTLY MID 40S TO LOW 50S AND CLOSE TO 40 DEGREES IN
THE COOLEST PARTS OF THE POCONOS.
LONG TERM /THURSDAY THROUGH MONDAY/
HIGH PRESSURE WILL BEGIN RETREATING EASTWARD AGAIN FOR
THURSDAY, WITH INCREASING CLOUDS AND PERHAPS A STRAY SHOWER
LATER IN THE DAY ACROSS WESTERN AREAS AS ANOTHER WARM FRONT
APPROACHES. HIGHS MOSTLY 70S, 60S SHORE AND POCONOS.
BETTER CHANCE OF SHOWERS THURSDAY NIGHT AND FRIDAY AS THE WARM
FRONT LIFTS THROUGH ON THE SOUTHEAST SIDE OF LOW PRESSURE
PASSING TO OUR NORTHWEST. THIS WILL HOLD LOWS UP THURSDAY NIGHT,
GENERALLY ABOUT 10 DEGREES MILDER THAN WEDNESDAY NIGHT, WITH
50S AND 60S COMMON. SHOULD BREAK INTO THE WARM SECTOR FOR
FRIDAY, WITH MOST AREAS OUTSIDE THE POCONOS AND SHORE REACHING
THE 80S AGAIN...70S POCONOS AND SHORE.
SHOWERS AND T-STORMS LIKELY IMPACT THE AREA LATER FRIDAY INTO
FRIDAY NIGHT AS THE AFOREMENTIONED COLD FRONT PUSHES ACROSS THE
REGION. STILL LOTS OF UNCERTAINTY ABOUT INTENSITY, BUT WE'LL BE
WATCHING ANY SEVERE WEATHER RISK CLOSELY.
LATEST GUIDANCE GENERALLY HAS THE FRONT CLEAR OUR REGION BY
EARLY SATURDAY, WITH A SIGNIFICANTLY COOLER COUPLE OF DAYS FOR
NEXT WEEKEND. HIGHS WILL MOSTLY BE NEAR 70 BOTH DAYS WITH 60S
POCONOS. WILL NEED TO WATCH POTENTIAL FOR LINGERING CLOUDS OR
EVEN A SHOWER WRAPPING IN BEHIND THE FRONT WITH THE UPPER LOW
FOR SATURDAY, BUT SUNDAY IS MORE LIKELY TO BE RELATIVELY DRY AND
SUNNY. LOWS SATURDAY NIGHT WILL BE ON THE COOL SIDE AGAIN, WITH
40S COMMON, 30S IN THE POCONOS.
AVIATION /19Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR/SKC. SW WINDS 5 TO 10 KT, THOUGH S-SE BEHIND THE
SEA BREEZE AT KACY/KMIV/KILG THROUGH 00Z. S WINDS 5 KT OR LESS
AFTER 00Z. HIGH CONFIDENCE.
TUESDAY...VFR/SKC-FEW250. SW WINDS 5 TO 10 KT IN THE MORNING,
INCREASING TO 10 TO 15 KT WITH 20 TO 25 KT GUSTS IN THE
AFTERNOON. HIGH CONFIDENCE.
OUTLOOK...
SLIGHT CHANCE OF SHOWERS TUESDAY NIGHT WITH PASSING COLD FRONT
MAY RESULT IN BRIEF REDUCTIONS, BUT UNLIKELY. VFR SHOULD THEN
PREVAIL AGAIN WEDNESDAY AND WEDNESDAY NIGHT. SLIGHT CHANCE OF
SHOWERS RETURNS THURSDAY WITH RESTRICTIONS POSSIBLE, BUT THESE
ARE MORE LIKELY FRIDAY INTO FRIDAY NIGHT AND EARLY SATURDAY WHEN
SHOWERS MAY BE ACCOMPANIED BY THUNDER.
MARINE
SUB-SMALL CRAFT ADVISORY CONDITIONS TONIGHT. SW WINDS 10 TO 15
KT WITH 2 TO 3 FT SEAS. A SCA REMAINS IN EFFECT STARTING TUESDAY
AFTERNOON AS SW WINDS INCREASE TO 15 TO 20 KT WITH 25 TO 30 KT
GUSTS. SEAS WILL BUILD TO 4 TO 6 FT.
OUTLOOK...
ADVISORY CONDITIONS CONTINUING FOR THE ATLANTIC COASTAL WATERS
THROUGH TUESDAY NIGHT.
CONDITIONS LIKELY SUBSIDE BELOW SCA LEVELS DURING THE MORNING
WEDNESDAY AS A COLD FRONT SLIPS SOUTH OF THE AREA. SUB-SCA
CONDITIONS SHOULD THEN PREVAIL THROUGH THURSDAY BEFORE RETURNING
TO SCA ON SOUTHERLY FLOW AHEAD OF THE NEXT COLD FRONT ON
FRIDAY. THIS FRONT COULD ALSO BE ACCOMPANIED BY SHOWERS AND
THUNDERSTORMS. CONDITIONS IMPROVING ON SATURDAY.
FIRE WEATHER
ON TUESDAY, DEW POINTS WILL BE RISING, BUT TEMPERATURES WILL
RISE AS WELL, AND THIS WILL KEEP MINRH VALUES LOW. MINRH VALUES
WILL RANGE FROM 30 TO 35 PERCENT ACROSS MOST OF NEW JERSEY AND
DELAWARE, AND FROM 35 TO 40 PERCENT ACROSS SOUTHEAST
PENNSYLVANIA AND THE EASTERN SHORES OF DELAWARE. WILL BE IN
CONTACT WITH THE STATE FIRE WEATHER PARTNERS REGARDING THE NEED
FOR A SPECIAL WEATHER STATEMENT.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ450>453.
SMALL CRAFT ADVISORY FROM 3 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ454-455.
SYNOPSIS...RCM/STAARMANN
NEAR TERM...MPS
SHORT TERM...RCM/STAARMANN
LONG TERM...RCM/STAARMANN
AVIATION...MPS/RCM
MARINE...MPS/RCM
FIRE WEATHER...MPS
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