828
FXUS61 KPHI 140619
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
219 AM EDT SUN SEP 14 2025
SYNOPSIS
A WEAKENING COLD FRONT APPROACHES THE REGION LATE TONIGHT. HIGH
PRESSURE BRIEFLY BUILDS IN ON MONDAY BEFORE WEAKENING AND
SHIFTING NORTHEASTWARD. MEANWHILE, A COASTAL LOW WHICH IS
EXPECTED TO DEVELOP OFF THE COAST OF THE CAROLINAS LATER TONIGHT
WILL GRADUALLY DRIFT NORTHWARD, APPROACHING OUR REGION TUESDAY
INTO THURSDAY BEFORE DISSIPATING. LATE IN THE WEEK, A COLD FRONT
MAY APPROACH THE REGION.
NEAR TERM /THROUGH TONIGHT/
TONIGHT, FAIR WEATHER IS EXPECTED WITH HIGH PRESSURE OVERHEAD.
UNDER MOSTLY CLEAR SKIES, TEMPERATURES WILL DROP INTO THE UPPER
50S TO LOW 60S FOR THE REGION. PATCHY RURAL FOR MAY DEVELOP
LATE, SO WE HAVE INCLUDED THAT IN THE GRIDS ATTM. LIGHT WINDS
OVERNIGHT.
ON SUNDAY, HIGH PRESSURE WILL REMAIN ACROSS THE AREA, SO THE FAIR
WEATHER WILL CONTINUE. THERE COULD BE SOME PATCHY MORNING FOG ACROSS
THE RURAL AREAS LIKE ON SATURDAY MORNING. AFTER THAT, THERE WILL BE
MOSTLY SUNNY SKIES EARLY THEN SOME AFTERNOON CLOUDS. HIGH TEMPS ON
SUNDAY WILL BE MILDER THAN TODAY WITH LOW/MID 80S COMMON ACROSS THE
AREA. HUMIDITY LEVELS WILL REMAIN IN CHECK HOWEVER WITH DEW POINTS
IN THE LOW 60S.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
WE SHOULD HAVE A BRIEF PERIOD OF HIGH PRESSURE AND TRANQUIL
CONDITIONS ON MONDAY, FOLLOWED BY INCREASING CHANCES FOR RAIN
SHOWERS ESPECIALLY CLOSER TO THE COAST AS A WEAK COASTAL LOW
MEANDERS CLOSER TO OUR REGION TUESDAY INTO WEDNESDAY.
REGARDLESS OF WHERE THE FRONT ENDS UP LATE TONIGHT/MONDAY MORNING,
EXPECT ONLY MODESTLY COOLER CONDITIONS ON MONDAY AS COMPARED TO
TODAY AS THE FRONT WILL BE WEAKENING AS IT APPROACHES THE REGION.
HIGH TEMPERATURES ON MONDAY SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL,
RANGING FROM THE MID 70S ALONG THE COAST AND IN THE POCONOS TO LOWER
80S FOR MOST INLAND LOCATIONS.
THE BIGGEST CHANGE IN THIS PERIOD IS THE EARLIER POTENTIAL ARRIVAL
OF BOTH RAIN AND BREEZY CONDITIONS ALONG THE COAST DUE TO THE
COASTAL LOW. IT STILL APPEARS THE COAST LOW WILL BE WEAK, AND
WEAKENING AS IT GETS THIS FAR NORTH, SO AT THIS POINT, IT LOOKS LIKE
WIND GUSTS UP TO 30 MPH ALONG THE COAST, AND WIDESPREAD RAIN AMOUNTS
NEAR OR BELOW 1.5 INCHES. ADDITIONALLY, WITH PERSISTENT ONSHORE
FLOW, BOUNDARY LAYER HEATING WILL BE TEMPERED, LIMITING INSTABILITY.
CONSEQUENTLY, THERE IS VERY LITTLE RISK FOR ANY SIGNIFICANT IMPACTS;
OUR REGION ISN'T OUTLOOKED IN THE EXCESSIVE RAINFALL OUTLOOK, WINDS
SHOULD STAY WELL BELOW IMPACTFUL LEVELS, AND WHILE WE MAY SEE SOME
THUNDERSTORMS, AT THIS POINT THE RISK FOR SEVERE STORMS APPEARS
VERY LOW (LESS THAN 5%).
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
BY THURSDAY, THE REFLECTION OF THE COASTAL LOW AT THE SURFACE WILL
BE VERY DIFFUSE, IF NOT COMPLETELY DISSIPATED. HOWEVER, A MID AND
UPPER LEVEL OPEN WAVE TROUGH MAY STILL BE NEAR OUR REGION, RESULTING
IN CONTINUED CHANCES FOR RAIN, PRIMARILY FOR THE COASTAL PLAINS.
ONCE THE MID/UPPER LEVEL TROUGH SLIDES EASTWARD BY LATE THURSDAY, WE
COULD SEE A BRIEF WARM UP ON FRIDAY, THANKS IN PART TO A SHORT WAVE
RIDGE. HOWEVER, IT STILL APPEARS A COLD FRONT WILL APPROACH THE
REGION LATE IN THE WEEK. IT HAS SOME CHARACTERISTICS OF A BACKDOOR
COLD FRONT WHICH ARE NOTORIOUSLY HARD TO MODEL, ESPECIALLY WITH
RESPECT TO TIMING, THIS FAR OUT, SO HAVE STAYED CLOSE TO THE BLEND
OF GUIDANCE.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...PRIMARILY VFR. SLIGHT CHANCE (15-20%) OF FOG
DEVELOPMENT AT KMIV/KACY. WINDS LIGHT AND VARIABLE, UNDER 5 KT,
THOUGH A SOUTHERLY DIRECTION MAY BE FAVORED AT TIMES. MODERATE
CONFIDENCE.
TODAY...VFR. LIGHT AND VARIABLE WINDS BECOME NORTH/NORTHEASTERLY
AROUND 5-10 KT BY 14Z-15Z. A SEA-BREEZE SHOULD DEVELOP, TURNING
WINDS MORE EAST/SOUTHEASTERLY AT KACY BETWEEN 18Z-19Z, KMIV
BETWEEN 19Z-21Z, AND THE I-95 TERMINALS BETWEEN 22Z-00Z.
MODERATE CONFIDENCE IN TIMING OF WIND SHIFT WITH SEA-BREEZE
MOVING INLAND. HIGH CONFIDENCE IN PREVAILING VFR.
TONIGHT...PRIMARILY VFR. SMALL CHANCE (10%) OF FOG BRINGING
RESTRICTIONS TO KMIV/KACY. WINDS OUT OF THE EAST/NORTHEAST 5 KT
OR LESS.
OUTLOOK...
MONDAY AND TUESDAY...PREVAILING VFR FOR MOST TAF SITES. MVFR OR IFR
POSSIBLE (30-60% CHANCE) WITH LOW CLOUDS, AND BRIEF VISIBILITY
RESTRICTIONS IN RAIN SHOWERS.
TUESDAY NIGHT THROUGH THURSDAY...30 TO 60 % CHANCE OF PERIODS OF
MVFR OR IFR CONDITIONS WITH RAIN SHOWERS.
MARINE
OVERALL, FAIR WEATHER WILL PREVAIL FOR THE WATERS FOR TONIGHT
AND SUNDAY. WINDS WILL BE RATHER GENTLE WITH S/SW WINDS THRU THE
PERIOD. SEAS WILL AVERAGE 2 TO 3 FT FOR THE OCEAN AND 1 TO 2 FT
FOR DELAWARE BAY.
OUTLOOK...
MONDAY...WINDS AND SEAS SHOULD STAY BELOW SCA CRITERIA.
TUESDAY THROUGH WEDNESDAY NIGHT...SCA CONDITIONS ARE LIKELY (60% OR
MORE) FOR AT LEAST A PORTION OF THIS PERIOD. AREAS SOUTH OF GREAT
EGG INLET ARE LIKELY TO SEE SCA CONDITIONS DEVELOP THE EARLIEST,
WITH WINDS AT OR ABOVE 25 KT POSSIBLE AS EARLY AS PRE-DAWN TUESDAY.
SEAS ABOVE 5 FEET ARE LIKELY TO DEVELOP ALONG THE COAST BY LATE
TUESDAY. MAIN PERIOD OF CONCERN FOR THE DELAWARE BAY IS DURING THE
DAY ON TUESDAY AND PRIMARILY DUE TO WINDS AT OR JUST ABOVE 25 KT.
THURSDAY...INCREASING CHANCE (80% OR HIGHER) THAT WINDS AND SEAS
WILL SUBSIDE BELOW SCA CRITERIA BEFORE THURSDAY MORNING.
RIP CURRENTS...
FOR TODAY, WINDS BECOME MORE SOUTHERLY AROUND 10-15 MPH.
BREAKING WAVES WILL BE AROUND 1-2 FEET WITH AN EASTERLY SWELL
AROUND 7-8 SECONDS. DUE TO WINDS BECOMING MORE SHORE PARALLEL
AND BREAKING WAVE HEIGHTS SLIGHTLY LOWER, THERE WILL BE A LOW
RISK FOR RIP CURRENTS.
FOR MONDAY, THE WINDS BACK TO EASTERLY AT AROUND 10 TO 15 MPH AND
BREAKING WAVES INCREASE TO AROUND 2 TO 3 FEET WITH A CONTINUING
EASTERLY SWELL AROUND 8 SECONDS. DUE TO THE WINDS BECOMING ONSHORE
ALONG WITH BUILDING WAVE HEIGHTS THERE IS EXPECTED TO BE A MODERATE
RISK OF RIP CURRENTS AT ALL BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...JOHNSON
NEAR TERM...OHARA
SHORT TERM...JOHNSON
LONG TERM...JOHNSON
AVIATION...HOEFLICH/JOHNSON
MARINE...JOHNSON/OHARA
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