445
FXUS61 KPHI 041900
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
300 PM EDT MON AUG 4 2025
SYNOPSIS
HIGH PRESSURE WEAKENS TONIGHT INTO TUESDAY AS ANOTHER HIGH PRESSURE
SYSTEM BUILDS TO OUR NORTH AND NORTHEAST RIGHT INTO THE END OF THE
WEEK. THIS HIGH THEN BEGINS TO SHIFT OFFSHORE OVER THE WEEKEND AND
INTO EARLY NEXT WEEK, ALLOWING SOUTHERLY FLOW TO BRING BACK THE HEAT
AND HUMIDITY INTO THE REGION ALONG WITH MORE UNSETTLED WEATHER.
NEAR TERM /THROUGH TUESDAY/
DRY AND PLEASANT MID SUMMER CONDITIONS CONTINUING WITH A SLIGHT
UPTICK IN TEMPERATURES AND HUMIDITY THROUGH TUESDAY.
SHORTWAVE RIDGING WILL BUILD OVER THE REGION INTO TONIGHT, WHICH A
SHORTWAVE TROUGH BEGINNING TO APPROACH BY LATE TUESDAY. AT THE
SURFACE, STRONG AND EXPANSIVE HIGH PRESSURE WILL REMAIN TO OUR NORTH
AND NORTHEAST THROUGH TUESDAY. THIS WILL CONTINUE TO SUPPORT AN
ONSHORE FLOW REGIME AT THE SURFACE.
FOLLOWING A WARM AND DRY AFTERNOON, TEMPERATURES WILL FALL WELL INTO
THE 60S TONIGHT. THE ONSHORE FLOW HAS LED TO SLIGHTLY HIGHER
DEWPOINTS COMPARED TO PREVIOUS DAYS, AND AIRMASS MODIFICATION HAS
ALLOWED FOR A SLIGHT INCREASE IN TEMPERATURES ACROSS THE BOARD AS
WELL. SO WHILE NOT AS COOL AS PREVIOUS NIGHTS, STILL BELOW NORMAL
TEMPERATURES EXPECTED TONIGHT. GIVEN THE HIGHER HUMIDITY, SOME
PATCHY FOG IS POSSIBLE.
FOR TUESDAY, THE EASTERLY FLOW WILL CONTINUE WITH SIMILAR CONDITIONS
TO TODAY. HIGHS MAINLY IN THE MID TO UPPER 80S (NEAR 80 DEGREES FOR
THE HIGHER ELEVATIONS AND COASTS). WITH THE SHORTWAVE TROUGH
APPROACHING FROM THE WEST, WE'LL SEE AN INCREASE IN CIRRUS
COVERAGE.
SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/
SURFACE HIGH WILL BEGIN TO STRENGTHEN OVER QUEBEC AND NORTHERN NEW
ENGLAND TUESDAY NIGHT INTO WEDNESDAY, HELPING REINTRODUCE EAST TO
NORTHEAST FLOW ACROSS THE REGION. THIS WILL HELP KEEP SKIES A BIT
CLOUDY, WHICH WILL KEEP TEMPERATURES A BIT WARMER AT NIGHT, BUT
COOLER DURING THE DAY. LOWS TUESDAY NIGHT WILL BE IN THE MID 60S TO
AROUND 70. HIGHS ON WEDNESDAY WILL FALL BACK INTO THE LOW TO MID
80S, THOUGH DEW POINTS WILL INCREASE A TAD WITH ONSHORE FLOW,
INCHING BACK INTO THE MID 60S. GUIDANCE SUGGEST A FEW LIGHT SHOWERS
MAY TRY TO DEVELOP INLAND WITH A WEAK SURFACE TROUGH DEVELOPING, BUT
PROBABILITIES REMAIN RATHER LOW, THEREFORE MOST LOCATIONS MAY REMAIN
MOSTLY DRY. COOL ONSHORE FLOW WILL ALLOW TEMPS WEDNESDAY NIGHT TO
FALL INTO THE 60S.
LONG TERM /THURSDAY THROUGH MONDAY/
HIGH PRESSURE TO OUR NORTH WILL BE SLOW TO MOVE THROUGH THE WEEKEND,
KEEPING TEMPERATURES ON THE COOLER SIDE FOR A FEW MORE DAYS. HIGHS
ON THURSDAY WILL BE IN THE UPPER 70S TO LOW 80S WITH PARTLY TO
MOSTLY CLOUDY SKIES. HIGH PRESSURE WILL SHIFT SLIGHTLY SOUTH AND
EAST, CLOSER TOWARDS THE SOUTHERN NEW ENGLAND COAST, PROVIDING US
WITH BETTER OVERALL SUBSIDENCE AS A RESULT. MOSTLY SUNNY SKIES ARE
EXPECTED WITH TEMPERATURES SLIGHTLY WARMING INTO THE LOW TO MID 80S
FRIDAY AFTERNOON. A FEW ISOLATED SHOWERS CANNOT BE RULED OUT WITH
CONSENSUS GUIDANCE SHOWING SOME PROBABILITIES ACROSS THE SOUTHERN
DELMARVA, BUT MOST LOCATIONS SHOULD REMAIN DRY BOTH DAYS.
INTO THE WEEKEND, HIGH PRESSURE WILL CONTINUE TO SHIFT SOUTH AND
EAST, MOVING FAR OFFSHORE INTO THE ATLANTIC BY EARLY NEXT WEEK. THIS
WILL BRING SOUTHERLY FLOW BACK INTO THE REGION, RESULTING IN
GRADUALLY WARMING TEMPERATURES AND HUMIDITY CREEPING BACK UP. THIS
WILL ALSO HELP OPEN THE DOOR TO MORE UNSETTLED WEATHER COME SUNDAY
AND MONDAY. GLOBAL GUIDANCE IS HINTING AT A POSSIBLE LOW ACROSS THE
SOUTHEAST CREEPING NORTHWARD, BUT THERE REMAINS ABUNDANT UNCERTAINTY
WITH THE TIMING, PLACEMENT, AND OVERALL EVOLUTION WITH THIS
SYSTEM.
AVIATION /19Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 00Z...VFR. WINDS BECOMING SOUTHERLY BEHIND THE SEA BREEZE
AROUND 5-10 KTS, EXCEPT REMAINING LIGHT AND VARIABLE AT RDG/ABE.
HIGH CONFIDENCE.
TONIGHT...VFR. WINDS BECOMING LIGHT AND VARIABLE TO CALM BY 03-06Z.
HIGH CONFIDENCE.
TUESDAY...VFR. EAST TO SOUTHEAST WINDS INCREASING TO 5-10 KTS. HIGH
CONFIDENCE.
OUTLOOK...
TUESDAY NIGHT THROUGH THURSDAY NIGHT...MOSTLY VFR. SOME RISK OF
FOG AND LOW STRATUS POSSIBLE AT NIGHT.
FRIDAY AND SATURDAY...VFR LIKELY.
MARINE
NO MARINE HAZARDS EXPECTED THROUGH TUESDAY. WINDS 10 KTS OR LESS,
AND SEAS 3-4 FEET.
OUTLOOK...
TUESDAY NIGHT...THE CONDITIONS ARE ANTICIPATED TO BE BELOW
SMALL CRAFT ADVISORY CRITERIA.
WEDNESDAY THROUGH FRIDAY...SMALL CRAFT ADVISORY CONDITIONS
POSSIBLE ACROSS OUR OCEAN ZONES, MAINLY DUE TO 5 FOOT SEAS.
SATURDAY...CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT
ADVISORY CRITERIA.
RIP CURRENTS...
FOR TODAY AND TUESDAY, EAST TO NORTHEAST WINDS LOOK TO BE
AROUND 10-15 MPH FOR ALL BEACHES. EASTERLY SWELL OF 3-4 FEET
AROUND 7-8 SECONDS LOOKS TO RESULT IN BREAKING WAVES OF AROUND
2-3 FEET AT ALL BEACHES. AS A RESULT, A MODERATE RISK FOR THE
DEVELOPMENT OF RIP CURRENT IS FORECAST FOR BOTH THE JERSEY SHORE
AND DELAWARE BEACHES TODAY AND TUESDAY.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR PAZ070-071-
101>106.
NJ...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR NJZ012>019-
021.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...MJL
NEAR TERM...STAARMANN
SHORT TERM...MJL
LONG TERM...MJL
AVIATION...MJL/STAARMANN
MARINE...MJL/STAARMANN
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