150
FXUS61 KPHI 241725
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
125 PM EDT THU APR 24 2025
SYNOPSIS
HIGH PRESSURE ACROSS THE AREA THIS MORNING WILL SHIFT OFFSHORE
TODAY, WITH A WARM FRONT LIFTING NORTHWARD ACROSS THE AREA FRIDAY
NIGHT. A COLD FRONT WILL FOLLOW SATURDAY EVENING AS LOW PRESSURE
LIFTS TO THE NORTHEAST OUT OF THE OHIO VALLEY AND INTO NEW ENGLAND.
HIGH PRESSURE RETURNS FOR THE END OF THE WEEKEND AND REMAIN IN
CONTROL THROUGH EARLY NEXT WEEK.
NEAR TERM /THROUGH FRIDAY/
NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST, OTHER THAN SOME
MINOR HOURLY FORECAST ADJUSTMENTS. HIGH LEVEL CLOUDS WILL
CONTINUE FOR THE SOUTHERN HALF OF THE FORECAST AREA, WHILE SOME
LOWER LEVEL CUMULUS CLOUDS COULD DEVELOP ACROSS THE NORTHERN
HALF, ESPECIALLY ACROSS THE HIGHER ELEVATIONS OF NORTHEAST
PENNSYLVANIA AND NORTHERN NEW JERSEY.
SURFACE HIGH PRESSURE WILL GRADUALLY DRIFT OFFSHORE THROUGH THE
DAY TODAY WITH LIGHT WINDS EXPECTED THROUGH MOST OF THE
MORNING. BY MID AFTERNOON, SOUTH TO SOUTHWESTERLY FLOW WILL
INCREASE TO AROUND 5 TO 10 MPH, WITH OCCASIONAL GUSTS AROUND 15
MPH, WHICH WILL PUSH TEMPS TOWARDS THE UPPER 70S.
HEADING INTO THE OVERNIGHT HOURS, A WARM FRONT WILL START TO LIFT
NORTH ACROSS PORTIONS OF VA AND WILL ARRIVE BY FRIDAY MORNING. WARM
AIR ADVECTION WITH AN INCREASE IN MOISTURE WILL LEAD TO IN AN
INCREASE IN CLOUD COVER WITH TEMPERATURES WARMING INTO WELL INTO THE
70S AS THE RETURN FLOW SETS UP. SENSIBLE WEATHER SHOULD CONTINUE TO
BE DRY THROUGH THE AFTERNOON BEFORE A FRONTAL SYSTEM STARTS TO
APPROACH FROM THE WEST.
SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
THE FRIDAY NIGHT THROUGH SATURDAY PERIOD LOOKS UNSETTLED AND WET,
THOUGH THE TREND HAS BEEN LOWER QPF, MORE PROGRESSIVE, AND LOWER
THREAT FOR HEAVY RAIN.
INCOMING TROUGH COMES IN ON FRIDAY NIGHT WITH A STRENGTHENING
SURFACE LOW EXPECTED TO PASS WELL TO THE NORTH ON SATURDAY, DRAGGING
A FRONT THROUGH OUR REGION. MODEST WARM-AIR ADVECTION ON FRIDAY
NIGHT AND WEAK PVA WILL RESULT IN SOME SHOWERS OVERNIGHT. AS THE
INCOMING TROUGH ADVANCES AND THE FRONT GETS CLOSER, SOME HEAVIER
SHOWERS AND ISOLATED THUNDERSTORMS MOVE IN FOR SATURDAY. THIS BRINGS
A SOMEWHAT WET DAY FOR THE FIRST HALF OF THE WEEKEND, THOUGH IT
WON'T BE A TOTAL WASHOUT. QPF AMOUNTS HAVE COME DOWN, AND THINKING
MOST AREAS END UP WITH A QUARTER TO THREE QUARTERS OF AN INCH OF
RAIN WHEN ALL IS SAID AND DONE. NO REAL THREAT FOR SEVERE WEATHER OR
FLASH FLOODING, SO THIS SHOULD JUST BE A BENEFICIAL RAIN.
THE COLD FRONT ADVANCES QUICKLY ON SATURDAY, AND SHOULD BE OFFSHORE
BY EARLY SATURDAY NIGHT. SATURDAY NIGHT LOOKS MAINLY DRY, BUT IT
COULD BE A BIT BREEZY IN THE WAKE OF THE FRONT, WITH COLD AIR
ADVECTION RAMPING UP.
TEMPERATURES WILL BE MILD ON FRIDAY NIGHT WITH LOWS HOVERING
AROUND 60. ALTHOUGH IT WILL BE CLOUDY WITH PERIODS OF RAIN,
SATURDAY IS SHAPING UP TO FEATURE ABOVE NORMAL TEMPERATURES IN
THE LOW TO MID 70S. WITH THE FRONT COMING THROUGH AND A COLDER
AIRMASS WORKING IN, LOWS DROP INTO THE MID TO UPPER 40S ON
SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
FOLLOWING THE PASSAGE OF A COLD FRONT ON SATURDAY NIGHT, AN
EXPANSIVE AREA OF HIGH PRESSURE BEGINS TO MOVE IN, ACCOMPANIED BY A
STRONG UPPER LEVEL RIDGE. THIS RIDGE WILL BRING IMPRESSIVE HEIGHT
RISES AND MUCH WARMER TEMPERATURES BY THE MIDDLE OF NEXT WEEK IN
ADDITION TO QUIET AND DRY CONDITIONS.
NORTHERLY FLOW ON THE EAST SIDE OF THE HIGH ON SUNDAY WILL BRING
TEMPERATURES NEAR NORMAL IN THE 60S. THE SURFACE HIGH MOVES OVERHEAD
ON MONDAY AND OFFSHORE BY MONDAY NIGHT, WITH RETURN FLOW SETTING UP
FOR TUESDAY AND WEDNESDAY. THIS WILL RESULT IN INCREASING
TEMPERATURES THROUGH THE WEEK WITH 70S ON MONDAY, AND 80S TUESDAY
AND WEDNESDAY. ONLY CHANCE FOR RAIN IN THE LONG TERM COMES FOR
WEDNESDAY, WHERE A COLD FRONT WILL BRING TEMPERATURES BACK TOWARD
MORE SEASONAL LEVELS TO CLOSE OUT NEXT WEEK. GIVEN THAT THE AIRMASS
WILL BE QUITE WARM, CANNOT RULE OUT SOME THUNDERSTORMS IF THE FRONT
COMES IN DURING THE AFTERNOON OR EARLY EVENING. STILL A LONG WAY OUT
THOUGH FOR SPECIFICS, BUT SOMETHING TO WATCH OVER THE COMING DAYS.
AVIATION /17Z THURSDAY THROUGH MONDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR. SOUTH TO SOUTHWEST WINDS 5-10 KNOTS, WITH
OCCASIONAL GUSTS 15-20 KNOTS; GUSTS DROP OF BY SUNSET. HIGH
CONFIDENCE.
TONIGHT...VFR. SOUTH-SOUTHWEST WINDS 5-10 KNOTS, BECOMING LIGHT
AND VARIABLE MOST PLACES OVERNIGHT. HIGH CONFIDENCE.
FRIDAY... VFR.
OUTLOOK...
FRIDAY NIGHT...PRIMARILY VFR, THOUGH CONDITIONS COULD LOWER TO
MVFR/IFR WITH SHOWER CHANCES INCREASING AS THE NIGHT GOES ON.
SATURDAY...IFR/MVFR EXPECTED WITH 70-80% CHANCE OF RAIN AND 15-20%
CHANCE OF THUNDERSTORMS.
SATURDAY NIGHT...CONDITIONS LIFT QUICKLY BACK TO VFR AND REMAIN THAT
WAY THROUGH THE NIGHT. A FEW GUSTS 20-25 KT POSSIBLE OUT OF
THE NORTHWEST.
SUNDAY THROUGH MONDAY...VFR. SOUTH-SOUTHWEST WINDS 5-10 KNOTS,
WITH OCCASIONAL GUSTS 15-20 KNOTS IN THE AFTERNOON. HIGH
CONFIDENCE.
MARINE
SUB-SCA CONDITIONS EXPECTED THROUGH FRIDAY. WIND LESS THAN 15 KT.
SEAS 2 FEET OR LESS STARTING TO BUILD LATE FRIDAY.
OUTLOOK...
FRIDAY NIGHT...NO MARINE HEADLINES EXPECTED.
SATURDAY THROUGH SATURDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS
LIKELY (60-70%) WITH SEAS 4 TO 6 FEET AND A PERIOD OF 25-30 KT GUSTS
OUT OF THE NORTHWEST ON SATURDAY NIGHT.
SUNDAY THROUGH MONDAY...NO MARINE HEADLINES EXPECTED.
FIRE WEATHER
ANOTHER DRY DAY TODAY AS MIXING HEIGHTS INCREASE TO AROUND 5-
6,000 FT WITH RELATIVE HUMIDITIES MIXING OUT TO 20-30%. WINDS
BEGIN THE DAY LIGHT AND VARIABLE MOST PLACES, BUT WILL INCREASE
OUT OF THE SOUTH TO SOUTHWEST 5-10 MPH THROUGH MIDDAY, WITH
OCCASIONAL GUSTS IN AROUND 15 MPH LATER THIS AFTERNOON. 10 HOUR
FUELS BASED ON THE WFAS SHOULD BE IN THE 11-15% RANGE FOR MOST
OF THE AREA, SO THAT COMBINED WITH LIGHT FLOW SHOULD LEAD TO
LOWER SPREAD OF FIRE IF ANY ADDITIONAL FIRES GET STARTED.
RELATIVE HUMIDITY RECOVERS MORE THIS WEEKEND ALONG WITH SOME
POTENTIALLY BENEFICIAL RAIN.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ012-015.
MARINE...NONE.
SYNOPSIS...HOEFLICH/OHARA
NEAR TERM...DEAL/ROBERTSON
SHORT TERM...HOEFLICH
LONG TERM...HOEFLICH
AVIATION...DEAL/HOEFLICH/ROBERTSON
MARINE...DEAL/HOEFLICH
FIRE WEATHER...
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