876
FXUS61 KPHI 220609
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
209 AM EDT TUE SEP 22 2026
WHAT HAS CHANGED
AVIATION SECTION UPDATED FOR 06Z TAFS.
KEY MESSAGES
1. A FRONTAL BOUNDARY SOUTH OF THE REGION WILL KEEP RAIN
CHANCES AROUND THROUGH MID-WEEK, ESPECIALLY ACROSS SOUTHERN
PORTIONS OF THE AREA.
2. A CLOSED MID-LEVEL LOW EJECTING FROM THE OHIO VALLEY IS
EXPECTED TO LEAD TO THE DEVELOPMENT OF A SURFACE LOW OFF THE
EASTERN SEABOARD DURING THE MIDDLE AND LATTER PARTS OF THIS
WEEK. DEPENDING ON THE TRACK OF THE LOW, IT COULD BRING
INCREASED RAINFALL CHANCES TO THE REGION.
3. MULTIPLE ROUNDS OF POTENTIALLY SIGNIFICANT TIDAL FLOODING
EXPECTED FOR THIS WEEK. THE FIRST BATCH OF COASTAL FLOOD
HEADLINES HAVE BEEN ISSUED WITH MORE LIKELY TO COME.
4. DANGEROUS RIP CURRENTS AND HIGH SURF ARE EXPECTED AT THE
JERSEY SHORE AND DELAWARE BEACHES. SIGNIFICANT BEACH EROSION IS
ALSO LIKELY.
DISCUSSION
KEY MESSAGE 1...A FRONTAL BOUNDARY SOUTH OF THE REGION WILL
KEEP RAIN CHANCES AROUND THROUGH MID-WEEK, ESPECIALLY ACROSS
SOUTHERN PORTIONS OF THE AREA.
THE COLD FRONT THAT CROSSED THROUGH OUR REGION SUNDAY NIGHT IS
STALLING TO OUR SOUTH, AND REMAIN THERE THROUGH TUESDAY. IT
CONTINUES TO LOOK LIKE IT WILL LIFT A LITTLE CLOSER TO OUR
REGION TONIGHT INTO TUESDAY MORNING AS A WARM FRONT, BUT REMAIN
JUST SOUTH OF THE AREA. DUE TO THE CLOSER PROXIMITY, AND A MID
LEVEL SHORT WAVE TROUGH, MEAN THAT THAT PERIOD WILL HAVE THE
HIGHEST CHANCE FOR RAIN ACROSS OUR REGION. GIVEN THAT OUR LOW
WILL BE ON THE COOL SIDE OF THE FRONT, SHOWERS ARE GOING TO BE
THE MAIN MODE OF ANY PRECIPITATION. HOWEVER, ISOLATED, EMBEDDED
THUNDERSTORMS WILL BE POSSIBLE OVER DELMARVA, PARTICULARLY
DURING THE DAY ON TUESDAY.
CONFIDENCE IS HIGH THAT TEMPERATURES WILL BE BELOW NORMAL
STARTING TUESDAY. IN FACT, TEMPERATURES WILL LIKELY STRUGGLE TO
GET OUT OF THE 60S AREAWIDE THROUGH MOST OF THIS WEEK.
KEY MESSAGE 2...A CLOSED MID-LEVEL LOW EJECTING FROM THE OHIO
VALLEY IS EXPECTED TO LEAD TO THE DEVELOPMENT OF A SURFACE LOW
OFF THE EASTERN SEABOARD DURING THE MIDDLE AND LATTER PARTS OF
THIS WEEK. DEPENDING ON THE TRACK OF THE LOW, IT COULD BRING
INCREASED RAINFALL CHANCES TO THE REGION.
CONFIDENCE CONTINUES TO INCREASE THAT AS A MID-LEVEL IMPULSE
TRACKS EASTWARD OUT OF PORTIONS OF THE MIDWEST AND OHIO VALLEY
TOWARDS THE EASTERN SEABOARD, SURFACE CYCLOGENESIS WILL OCCUR
OFF THE COAST OF THE CAROLINAS TUESDAY INTO TUESDAY NIGHT. THE
INITIAL TRACK OF THE DEVELOPING LOW IS EXPECTED TO BE TO THE
NORTHEAST, WELL OFFSHORE. HOWEVER, WITH A STRONG HIGH CENTERED
OVER PORTIONS OF QUEBEC, A SHARP PRESSURE GRADIENT OVER THE
REGION WILL AT LEAST LEAD TO BREEZY CONDITIONS THROUGH THURSDAY
NEAR THE COAST. IT SHOULD REMAIN MOSTLY DRY THROUGH THIS PERIOD
HOWEVER.
FRIDAY AND BEYOND, SIGNIFICANT UNCERTAINTY REMAINS. MODELS NOW
FALL INTO TWO RELATIVELY DISTINCT CAMPS, WITH ONE CAMP
CONTINUING TO TAKE THE LOW NORTHEAST AND AWAY FROM THE REGION.
THE OTHER CAMP HAS THE LOW DEVIATING DUE NORTHWARD OR EVEN
NORTHWESTWARD TO OUR REGION. THE EC ENSEMBLES ARE GENERALLY
CLUSTERED FAIRLY TIGHTLY NEAR THE DETERMINISTIC EC, WHICH WOULD
FAVOR THIS SCENARIO. ON THE OTHER HAND, THE DETERMINISTIC GFS
HAS THE LOW CONTINUING NORTHEASTWARD AND THE GEFS ONLY HAS A FEW
MEMBERS BRINGING THE LOW TOWARDS THE COAST.
UNFORTUNATELY, THE DIFFERENCE IN SENSIBLE WEATHER OUTCOMES
BETWEEN THESE TWO SCENARIOS IS SUBSTANTIAL. SHOULD THE LOW TRACK
NORTHEASTWARD AWAY FROM THE REGION, ANY RAIN WOULD BE CONFINED
TO THE IMMEDIATE COAST, IF ANY, AND WINDS WOULD DECREASE
QUICKER. A TRACK CLOSER TO THE COAST OR EVEN INTO THE COAST
WOULD LEAD TO POTENTIALLY SIGNIFICANT IMPACTS FROM RAIN AND
WIND. FOR NOW, POPS ARE MAINTAINED IN THE 20-40% RANGE, AND
HIGHEST SOUTHEAST OF I-95. IT IS WORTH NOTING THAT THERE ARE
SEVERAL MEMBERS IN THE ENSEMBLE SUITES WHICH FEATURE A MIDDLE
GROUND SCENARIO, WHERE THE LOW DOES DEVIATE SOME BUT STILL
REMAINS FAIRLY COMFORTABLY OFFSHORE. THIS SCENARIO WOULD LEAD TO
SOME IMPACTS FROM RAIN AND WIND, BUT THE INLAND EXTENT WOULD BE
FAIRLY LIMITED. WE WILL CONTINUE TO MONITOR TRENDS CLOSELY AS
WE TRY TO NAIL DOWN SPECIFIC IMPACTS AND TIMING OVER THE COMING
DAYS.
KEY MESSAGE 3...MULTIPLE ROUNDS OF POTENTIALLY SIGNIFICANT
TIDAL FLOODING EXPECTED FOR THIS WEEK. THE FIRST BATCH OF
COASTAL FLOOD HEADLINES HAVE BEEN ISSUED WITH MORE LIKELY TO
COME.
WITH A SLOW MOVING COASTAL STORM INCREASINGLY LIKELY, THE
THREAT FOR TIDAL FLOODING HAS INCREASED. STRONG ONSHORE FLOW
THAT IS PROJECTED TO LAST FOR SEVERAL DAYS WILL RESULT IN WATER
PILING UP ACROSS TIDAL TRIBUTARIES AND WITHIN BACK BAYS OF
COASTAL COMMUNITIES. TIDAL LEVELS WILL ALSO BE ENHANCED WITH
ASTRONOMICAL TIDES INCREASING WITH THE UPCOMING FULL MOON ON
SATURDAY. THIS COMBINATION OF FACTORS WILL LEAD TO WIDESPREAD
TIDAL FLOODING, SOME OF WHICH COULD GET TO THE MODERATE STAGE.
WHILE NOT CURRENTLY FORECAST, THE THREAT FOR MAJOR FLOODING IS
NOT OFF THE TABLE, ESPECIALLY GETTING NEAR THE FULL MOON.
MINOR TIDAL FLOODING BEGINS AS EARLY AS TOMORROW AFTERNOON AND
EVENING FOR SOME LOCATIONS. A COASTAL FLOOD ADVISORY WAS ISSUED
FOR OCEAN, ATLANTIC, AND CAPE MAY COUNTY IN NEW JERSEY AND KENT
AND SUSSEX COUNTY IN DELAWARE. FOR THOSE SAME AREAS, TIDE LEVELS
ARE EXPECTED TO INCREASE FOR WEDNESDAY AND THURSDAY,
POTENTIALLY GETTING TO MODERATE STAGE. A COASTAL FLOOD WATCH WAS
ISSUED FOR WEDNESDAY AND THURSDAY EVENING'S HIGH TIDE. MODERATE
TIDAL FLOODING COULD EVEN CONTINUE INTO THE WEEKEND. AS
MENTIONED ABOVE, CANNOT RULE OUT TIDE LEVELS REACHING MAJOR,
GIVEN THE SETUP.
FOR THE REST OF THE NJ COAST NORTH OF BARNEGAT INLET, TIDE
LEVELS ARE CURRENTLY FORECAST TO REACH MINOR ON WEDNESDAY AND
THURSDAY. COASTAL FLOOD ADVISORIES LIKELY WILL BE NEEDED, BUT
TIDE LEVELS ARE CURRENTLY FORECAST TO STAY BELOW MODERATE AT
THIS TIME AND LOWER WATER LEVELS THAN IN AREAS IN SOUTHERN
DELAWARE AND SOUTH JERSEY. THE SAME GOES FOR THE NEW JERSEY SIDE
OF DELAWARE BAY AND TIDAL DELAWARE RIVER.
WIDESPREAD MINOR TIDAL FLOODING IS NOT CURRENTLY EXPECTED
WITHIN THE CHESAPEAKE BAY. USUALLY, STRONG NORTHEAST WINDS DO
NOT RESULT IN TIDAL FLOODING IN THESE AREAS.
KEY MESSAGE 4...DANGEROUS RIP CURRENTS AND HIGH SURF ARE
EXPECTED AT THE JERSEY SHORE AND DELAWARE BEACHES. SIGNIFICANT
BEACH EROSION IS ALSO LIKELY.
A COASTAL STORM IS EXPECTED TO FORM OFFSHORE, RESULTING IN
HAZARDOUS CONDITIONS ALONG THE COAST. THE SURFACE LOW WILL
LINGER OFF OUR WATERS FOR MULTIPLE DAYS, BRINGING STRONG WINDS
AND HIGH SEAS FOR OUR MARINE ZONES. BY WEDNESDAY, BREAKING WAVES
WITHIN THE SURF ZONE OF 6 TO 12 FEET ARE EXPECTED. THIS WILL
CONTINUE THROUGH AT LEAST FRIDAY WITH THE COASTAL STORM
CURRENTLY PROGGED TO BE RIGHT AROUND THE BENCHMARK BY THE END OF
THIS WEEK. DANGEROUS RIP CURRENTS WILL ACCOMPANY THAT HIGH
SURF, MAKING IT EXTREMELY HAZARDOUS TO ENTER THE WATER AT ANY
TIME THIS WEEK. THE HIGH SURF AND STRONG WINDS COULD ALSO RESULT
IN SIGNIFICANT BEACH EROSION FOR THE JERSEY SHORE AND DELAWARE
BEACHES.
WITH HIGH CONFIDENCE IN THE RIP CURRENT AND HIGH SURF FORECAST,
THE HIGH RISK FOR LIFE THREATENING RIP CURRENTS WAS EXTENDED
THROUGH FRIDAY FOR ALL BEACHES. A HIGH SURF ADVISORY WAS ISSUED
FOR ALL BEACHES AS WELL FROM WEDNESDAY THROUGH AT LEAST FRIDAY,
WHEN BREAKING WAVES WITHIN THE SURF ZONE WILL BE AROUND 10 FEET
OR HIGHER.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...CEILINGS HAVE BEEN SLOW TO LOWER AND REMAIN MOSTLY
VFR AS OF 06Z, THOUGH CONTINUED LOWERING IS FORECAST THROUGH
09-12Z. ABE/TTN ARE MOST LIKELY TO REMAIN VFR THROUGH 12Z
OUTSIDE OF ANY VISIBILITY RESTRICTIONS IN RAIN SHOWERS.
ELSEWHERE, LOWERING TOWARD MVFR CEILINGS IS ANTICIPATED THROUGH
12Z, AND VISIBILITY MAY BRIEFLY DROP TO MVFR IN ANY STEADIER
RAIN SHOWERS. LOW CONFIDENCE ON TIMING OF RESTRICTIONS.
TUESDAY...MVFR EARLY, THEN AN IMPROVEMENT TO VFR IS LIKELY FOR
MOST TERMINALS BETWEEN 18-21Z (EXCEPT FOR ACY/MIV). SOME
SHOWERS LINGER INTO LATE MORNING, MAINLY SOUTH. PROBABILITY OF
IFR IS LOW. NORTHEASTERLY WINDS AROUND 10 KTS PREVAIL WITH
15-20 KT GUSTS. MODERATE CONFIDENCE.
TUESDAY NIGHT...MVFR RESTRICTIONS ARE POSSIBLE AT TIMES, MAINLY
FOR ACY/MIV WHERE MVFR CEILINGS ARE MOST LIKELY TO PERSIST
OVERNIGHT. ELSEWHERE, MVFR CEILINGS LIKELY. NORTHEAST WINDS
AROUND 10 KTS, GUSTING NEAR 20 KTS POSSIBLE AFTER 06Z. MODERATE
CONFIDENCE.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY...THERE WILL LIKELY BE AT LEAST SOME
PERIODS OF VFR CONDITIONS, BUT LOW CLOUDS AND RAIN AT TIMES
COULD STILL LEAD TO RESTRICTIONS. GUSTY NORTHEAST WINDS
POSSIBLE.
THURSDAY NIGHT THROUGH SATURDAY...A HIGH DEGREE OF UNCERTAINTY
REMAINS, BUT SUB-VFR CONDITIONS WILL BE POSSIBLE. GUSTY
NORTHEAST WINDS POSSIBLE.
MARINE
SMALL CRAFT ADVISORY CONDITIONS CONTINUE TO DEVELOP ON THE
ATLANTIC COASTAL WATERS, AND WILL DEVELOP BY TUESDAY MORNING FOR
THE DELAWARE BAY. EVEN THOUGH THIS IS AN UNUSUAL WIND DIRECTION
FOR SCA CONDITIONS ON THE BAY, MULTIPLE MODELS DEPICT A SEVERAL
HOUR PERIOD OF WIND GUSTS AT OR ABOVE 25 KT, SO HAVE ISSUED THE
SCA FOR THE BAY FROM TUESDAY MORNING THROUGH TUESDAY NIGHT.
TUESDAY NIGHT ONWARDS, SCA CONDITIONS ARE EXPECTED WITH PERIODS
OF GALES POSSIBLE. CONSEQUENTLY, A GALE WATCH REMAINS IN EFFECT
FOR ALL OF THE ATLANTIC FORECAST ZONES STARTING TUESDAY
EVENING, AND FOR THE DELAWARE BAY STARTING WEDNESDAY MORNING.
THE WATCH CURRENTLY GOES THROUGH THE DAY ON THURSDAY, WHEN WE
HAVE THE MOST CONFIDENCE IN GALE CONDITIONS.
GALE CONDITIONS MAY LINGER INTO FRIDAY AND SATURDAY DEPENDING
ON THE EVOLUTION OF THE COASTAL LOW, WHICH IS UNCERTAIN IN THIS
TIME FRAME.
THROUGHOUT MUCH OF THE PERIOD, HIGH SEAS ARE EXPECTED AND
VISIBILITY RESTRICTIONS WILL BE POSSIBLE AT TIMES IN RAIN.
RIP CURRENTS...SEE KEY MESSAGE 4.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM EDT
THIS EVENING FOR NJZ020-022>027.
COASTAL FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR NJZ020-022>027.
HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT THIS MORNING THROUGH
FRIDAY AFTERNOON FOR NJZ014-024>026.
HIGH SURF ADVISORY FROM 8 AM WEDNESDAY TO 6 PM EDT FRIDAY FOR
NJZ014-024>026.
DE...COASTAL FLOOD ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM EDT
THIS EVENING FOR DEZ002>004.
COASTAL FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR DEZ002>004.
HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT THIS MORNING THROUGH
FRIDAY AFTERNOON FOR DEZ004.
HIGH SURF ADVISORY FROM 8 AM WEDNESDAY TO 6 PM EDT FRIDAY FOR
DEZ004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 6 AM EDT
WEDNESDAY FOR ANZ430-431.
GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY AFTERNOON
FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ450>455.
GALE WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR
ANZ450>455-480>483-485.
DISCUSSION...AKL/COOPER/HOEFLICH
AVIATION...AKL/COOPER/MJL/STAARMANN
MARINE...AKL/COOPER/HOEFLICH
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