430
FXUS61 KPHI 290446
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1246 AM EDT TUE APR 29 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 TODAY/
AS OF 1245 AM, JUST SOME CIRRUS SLIDING ACROSS THE AREA AND NO
SIGNIFICANT CHANGES MADE WITH THIS UPDATE.
OTHERWISE, HIGH PRESSURE MOVES OFFSHORE OVERNIGHT. LOWS EXPECTED
TO DROP INTO THE MID 40S (NORTH) AND LOW 50S FOR THE METROS AND
DELMARVA. LIGHT WINDS EXPECTED OVERNIGHT.
WARM AIR ADVECTION INCREASES ON TUESDAY WITH TEMPERATURES WELL
ABOVE AVERAGE WITH HIGHS IN THE UPPER 70S TO LOW 80S, THOUGH
COOLER AT THE COASTS. AS A COLD FRONT APPROACHES, THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THAT APPROACHING FRONT AND HIGH
PRESSURE OFF THE SOUTHEAST COAST. SOUTHWESTERLY WINDS WILL
INCREASE TO 15-20 MPH WITH GUSTS UP TO 30 MPH.
ANY SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THAT APPROACHING
FRONT SHOULD HOLD OFF UNTIL TUESDAY EVENING.
SHORT TERM /TONIGHT 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 /06Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH TUESDAY...VFR. SOUTHWEST WINDS NEAR 5 KNOTS OR LOCALLY
LIGHT AND VARIABLE TO CALM THROUGH DAYBREAK, THEN SOUTHWEST
WINDS 5-10 KNOTS INCREASING TO 12-18 KNOTS WITH GUSTS UP TO 25
KNOTS FROM LATE MORNING THROUGH THE AFTERNOON. HIGH CONFIDENCE.
TUESDAY NIGHT...VFR WITH AN INCREASE IN MAINLY MID TO HIGH
LEVEL CLOUDS. A FEW SHOWERS OR A THUNDERSTORM CANNOT BE RULED
OUT INTO THE OVERNIGHT HOURS MOSTLY NEAR KABE AND KRDG, HOWEVER
THE CHANCES ARE TO LOW TO INCLUDE A MENTION IN THE TAFS. SOUTHWEST
WINDS 10-15 KNOTS DIMINISHING TO 5-10 KNOTS AND BECOMING WEST
TO NORTHWEST CLOSER TO DAYBREAK WEDNESDAY. MODERATE CONFIDENCE.
OUTLOOK...
VFR SHOULD 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
SMALL CRAFT ADVISORY CONDITIONS ARE FORECAST TO DEVELOP TUESDAY
AFTERNOON AS SOUTHWESTERLY WINDS INCREASE WITH GUSTS 25-30 KNOTS ON
THE OCEAN ZONES. THIS WILL CONTINUE MOST OF TUESDAY NIGHT. IT MAY
TAKE SOME TIME HOWEVER FOR THE STRONGER WINDS TO REACH THE SURFACE
GIVEN MUCH WARMER AIR MOVING OVER THE COOL OCEAN WATER (WATER
TEMPERATURES MOSTLY IN THE 50S). SEAS WILL ALSO BUILD IN RESPONSE TO
THE PERIOD OF STRONGER WINDS. FOR DELAWARE BAY, OPTED TO ISSUE A
SMALL CRAFT ADVISORY FOR TUESDAY AFTERNOON INTO EARLY TUESDAY
EVENING AS GUSTS TO AROUND 25 KNOTS OCCUR ESPECIALLY CLOSER TO THE
COAST.
OUTLOOK...
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 TODAY TO 7 PM EDT THIS EVENING
FOR ANZ430-431.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EDT WEDNESDAY FOR
ANZ450>455.
SYNOPSIS...RCM/STAARMANN
NEAR TERM...GORSE/MPS
SHORT TERM...RCM/STAARMANN
LONG TERM...RCM/STAARMANN
AVIATION...GORSE/RCM
MARINE...GORSE/RCM
FIRE WEATHER...PHI
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