798
FXUS61 KPHI 132341
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
741 PM EDT SUN SEP 13 2026
WHAT HAS CHANGED
UPDATED AVIATION AND KEY MESSAGE 1. ADDED FOG TO NEAR TERM PARTS
OF THE FORECAST.
KEY MESSAGES
1. A COLD FRONT MOVES THROUGH OVERNIGHT AND COULD BRING A FEW
SHOWERS AS THIS OCCURS.
2. HIGH PRESSURE BUILDS IN TO START THE WEEK AND WILL DOMINATE
THROUGH AT LEAST WEDNESDAY BRINGING FAIR AND DRY WEATHER.
3. A COLD FRONT THURSDAY INTO FRIDAY MAY BRING SOME SHOWERS AND
THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1...A COLD FRONT MOVES THROUGH OVERNIGHT AND COULD
BRING A FEW SHOWERS AS THIS OCCURS.
FOR TONIGHT, LOW PRESSURE CONTINUES TO PULL AWAY AS IT MOVES FROM
NEW ENGLAND INTO THE CANADIAN MARITIMES. THIS WILL HELP PULL A
SECONDARY FRONT THROUGH THE AREA FROM NORTH TO SOUTH OVERNIGHT.
AS THIS OCCURS THERE COULD BE A FEW SHOWERS BUT THE OVERALL
TREND SHOULD BE FOR SHOWERS WITH THE FRONT TO BE DIMINISHING IN
COVERAGE AS THE FRONT PUSHES SOUTH INTO OUR AREA. BEFORE THE
FRONT ARRIVES, THE HUMID AIR MASS AND CLEARING SKIES MAY LEAD TO
AREAS OF FOG DEVELOPING ACROSS THE AREA. ONCE THE FRONT PASSES,
THE INCREASING WINDS AND DRIER AIR WILL PUT AN END TO
KEY MESSAGE 2....HIGH PRESSURE BUILDS IN TO START THE WEEK AND WILL
DOMINATE THROUGH AT LEAST WEDNESDAY BRINGING FAIR AND DRY WEATHER.
HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH MONDAY AND MONDAY
NIGHT BRINGING MAINLY CLEAR SKIES AND TEMPERATURES A BIT BELOW
AVERAGE FOR THIS TIME OF YEAR. GENERALLY EXPECT HIGHS IN THE 70S
WITH A FEW PLACES ACROSS SOUTH JERSEY INTO DELMARVA POTENTIALLY
GETTING TO AROUND 80. NORTHERLY WINDS WILL ALSO ADVECT IN MUCH LOWER
DEW POINTS MAKING IT FEEL QUITE COMFORTABLE.
HIGH PRESSURE WILL REMAIN CENTERED NEAR THE AREA THROUGH TUESDAY
BEFORE STARTING TO SLOWLY MOVE OFF THE COAST HEADING INTO WEDNESDAY.
BOTH DAYS LOOK TO FEATURE CONTINUING PARTLY TO MOSTLY SUNNY SKIES
WITH A BIT OF A WARMING TREND BY WEDNESDAY ALONG WITH SOME INCREASE
IN HUMIDITY AS THE WINDS TURN MORE SOUTHERLY. EXPECT HIGHS BY
WEDNESDAY GENERALLY IN THE UPPER 70S TO LOW 80S EXCEPT A BIT COOLER
RIGHT NEAR THE COAST AND OVER THE POCONO PLATEAU.
KEY MESSAGE 3...A COLD FRONT THURSDAY INTO FRIDAY MAY BRING SOME
SHOWERS AND THUNDERSTORMS.
AN UPPER-LEVEL TROUGH ACROSS CENTRAL INTO EASTERN CANADA IS FORECAST
TO PUSH A COLD FRONT INTO OUR AREA AT THE END OF NEXT WEEK. WHILE
THE GUIDANCE, INCLUDING ENSEMBLES, ARE IN DECENT AGREEMENT SHOWING
THIS TROUGH, THERE ARE MODEL DIFFERENCES WITH THE AMPLIFICATION AND
THEREFORE SPEED OF THE TROUGH. THIS WILL HAVE IMPACTS TO THE COLD
FRONT ITSELF. IF THE MAIN ENERGY SLIDES FAR ENOUGH NORTH OF OUR
AREA, THE FRONT MAY TEND TO BE SLOWER MOVING. THIS SCENARIO WOULD
OPEN THE DOOR FOR A GREATER CHANCE FOR A ROUND OF CONVECTION. A
FASTER MOVEMENT TO THE FRONT WOULD LESSEN THE LENGTH OF CONVECTION
OVER OUR AREA. THE FRONT MAY THEN LINGER IN THE GENERAL VICINITY OF
THE AREA NEXT WEEKEND WHICH COULD KEEP CONDITIONS UNSETTLED AT
TIMES. DEPENDING ON HOW MUCH MOISTURE GETS DRAWN NORTHWARD ALONG THE
FRONT WILL DETERMINE THE HEAVY RAIN / FLOOD THREAT FOR LATE WEEK
INTO NEXT WEEKEND. AT THIS POINT THERE APPEARS TO BE AT LEAST SOME
THREAT BUT THE DETAILS SHOULD COME INTO BETTER FOCUS OVER THE NEXT
FEW DAYS.
AVIATION /00Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...PREVAILING VFR EARLY THEN PERIODS OF SUB-VFR IN FOG
POSSIBLE. WINDS BACKING TO MORE OF A WSW DIRECTION THIS EVENING
AT AROUND 5 KNOTS THEN SHIFTING BACK TO NW OVERNIGHT IN THE WAKE
OF A COLD FRONT. HIGH CONFIDENCE EXCEPT WITH REGARDS TO FOG FORMATION
AND DURATION.
MONDAY...VFR. WNW WINDS AROUND 10 KNOTS WITH GUSTS OF 15 TO 20
KNOTS AT TIMES.
OUTLOOK...
TUESDAY AND WEDNESDAY...VFR.
THURSDAY THROUGH FRIDAY...MOSTLY VFR. A FEW SHOWERS POSSIBLE.
MARINE
WINDS AND SEAS SHOULD STAY BELOW SMALL CRAFT ADVISORY CONDITIONS
THROUGH TONIGHT. WINDS GENERALLY SOUTHWEST AROUND 5-10 KNOTS
THROUGH THIS EVENING THEN SHIFTING TO NW 10-15 GUSTING UP TO 20
KNOTS LATE AT NIGHT.
MONDAY REMAINS BREEZY OVER THE WATERS WITH NORTHERLY WINDS
AROUND 15 TO 20 WITH SOME GUSTS UP TO 25 KNOTS POSSIBLE. HOLDING
OFF ON ISSUING AN SCA AT THIS TIME AS IT LOOKS TO BE A MARGINAL
EVENT AT BEST.
OUTLOOK...
TUESDAY THROUGH FRIDAY...THE CONDITIONS ARE ANTICIPATED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA.
RIP CURRENTS...
MONDAY...NORTH-NORTHWEST WINDS WILL BE AROUND 15 TO 20 MPH WITH
BREAKING WAVE HEIGHTS AROUND 1 TO 3 FEET. AN UNDERLYING 1 TO 2
FOOT SOUTHEAST SWELL WILL REMAIN WITH MIXED PERIODS. GIVEN THESE
CONDITIONS, HAVE OPTED TO MAINTAIN A LOW RISK FOR THE
DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR BOTH THE JERSEY SHORE
AND DELAWARE BEACHES.
TUESDAY...EAST-NORTHEAST WINDS WILL BE AROUND 10 TO 15 MPH WITH
BREAKING WAVE HEIGHTS OF 1 TO 2 FEET. AN UNDERLYING 2 TO 3 FOOT
NORTHEAST SWELL AROUND 5 TO 6 SECONDS WILL OCCUR AS WELL. GIVEN
THESE CONDITIONS, HAVE OPTED TO GO WITH A LOW RISK FOR RIP
CURRENTS FOR BOTH THE JERSEY SHORE AND DELAWARE BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...FITZSIMMONS/SJ/PO
AVIATION...FITZSIMMONS/PO
MARINE...DESILVA/FITZSIMMONS
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