570
FXUS61 KPHI 201932
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
332 PM EDT TUE OCT 20 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE #2 DISCUSSING COASTAL FLOODING. COASTAL
FLOOD ADVISORIES HAVE BEEN EXTENDED THROUGH WEDNESDAY EVENING.
KEY MESSAGES
1. A WELL OFFSHORE NOR'EASTER BRINGING COASTAL IMPACTS AND HAZARDOUS
MARINE CONDITIONS THROUGH THURSDAY.
2. A PROLONGED PERIOD OF ONSHORE FLOW WILL LEAD TO MULTIPLE ELEVATED
HIGH TIDE CYCLES THIS WEEK RESULTING IN ROUNDS OF COASTAL FLOODING.
3. FROST IMPACTS POSSIBLE FRIDAY NIGHT AND SATURDAY NIGHT WHERE THE
GROWING SEASON CONTINUES.
DISCUSSION
KEY MESSAGE 1...A WELL OFFSHORE NOR'EASTER BRINGING COASTAL IMPACTS
AND HAZARDOUS MARINE CONDITIONS THROUGH THURSDAY.
A CLOSED LOW OFF THE MID-ATLANTIC COAST WILL GRADUALLY SHIFT NORTH
AND EASTWARD THROUGH LATER THIS WEEK. THIS WILL CONTINUE TO SUPPORT
SURFACE LOW PRESSURE, WHICH IS FORECAST TO STRENGTHEN AS IT SLOWLY
MOVES NORTH AND NORTHEASTWARD (EVEN MEANDERS SOME FOR A TIME).
MEANWHILE, STRONG SURFACE HIGH PRESSURE WILL BECOME MORE CENTERED
ACROSS NORTHERN NEW ENGLAND THROUGH WEDNESDAY. THESE SYSTEMS WILL
RESULT IN A TIGHTENING PRESSURE GRADIENT INTO OUR AREA THROUGH LATE
WEDNESDAY.
WHILE THIS THIS NOR'EASTER REMAINS HUNDREDS OF MILES OFF OF OUR
COAST (AN OCEAN STORM), SOME IMPACTS ARE STILL BEING FELT FOR OUR
COASTAL AND MARINE AREAS. THE WIND FIELD HAS STRENGTHENED SOME TODAY
WITH STRONGER SURFACE WINDS BEING OBSERVED ACROSS MOST OF THE AREA.
SOME OF THIS WIND WILL DECOUPLE TONIGHT, ESPECIALLY FARTHER INLAND,
BUT STILL REMAIN BREEZE TO WINDY AT THE COAST. THIS CONTINUED NORTH
TO NORTH-NORTHEAST WIND WILL BUILD THE OFFSHORE SEAS AND THESE WILL
BE BREAKING INTO THE BEACHES RESULTING IN BEACH EROSION IN SOME
AREAS ESPECIALLY DURING TIMES OF HIGH TIDE. THE PRESSURE GRADIENT
SHOULD TEND TO TIGHTEN SOME MORE TONIGHT AND FOR PORTIONS OF WEDNESDAY
AS THE STORM IS FORECAST TO SHIFT WESTWARD SOME OR EVEN MAKE A SMALL
OFFSHORE LOOP ON WEDNESDAY. THIS SHOULD RESULT IN THE WINDS PEAKING
TONIGHT AND WEDNESDAY. FOR AREAS ALONG THE COAST, PEAK WIND GUSTS
IN THE 30-40 MPH RANGE ARE FORECAST AND THEN UP TO 30 MPH INLAND.
NO IMPACTS ARE EXPECTED INLAND GIVEN HOW FAR OFFSHORE THIS STORM
IS. SOME SHOWERS MAY TRY AND APPROACH THE IMMEDIATE COAST THOUGH
DURING WEDNESDAY, BUT OVERALL THE DRIER AIR ON THE WEST SIDE OF
THIS SYSTEM ALONG WITH THE OFFSHORE DISTANCE SHOULD KEEP THESE
AREAS MAINLY DRY. SOME CLOUDINESS SHOULD SPREAD WESTWARD FOR A
TIME WEDNESDAY, HOWEVER THIS MAY BE MAINLY THE MID TO HIGH LEVEL
VARIETY.
FOR THURSDAY AND FRIDAY, THE STORM WILL GRADUALLY HEAD FARTHER OUT
TO SEA AS AN INCOMING SYSTEM FROM THE NORTHWEST KICKS IT OUT. THIS
WILL QUICKLY LESSEN THE MARINE AND COASTAL IMPACTS, WHILE KEEPING
OUR WEATHER DRY AND PROVIDING A FRESH SHOT OF CHILLY AIR.
KEY MESSAGE 2...A PROLONGED PERIOD OF ONSHORE FLOW WILL LEAD TO
MULTIPLE ELEVATED HIGH TIDE CYCLES THIS WEEK RESULTING IN ROUNDS
OF COASTAL FLOODING.
AS THE NOR'EASTER MEANDERS OFFSHORE THROUGH THE MIDDLE OF THE WEEK,
THERE WILL BE A PERSISTENT AND STRONG NORTH-NORTHEAST WIND IN PLACE.
THIS WILL LEAD TO A PROLONGED PERIOD OF ONSHORE FLOW RESULTING IN
MULTIPLE ELEVATED HIGH TIDE CYCLES. RECENT FORECAST TRENDS HAVE BEEN
FLUCTUATING ON THE CRESTS OF THE HIGH TIDE CYCLES FOR THIS EVENT.
THE FIRST HIGH TIDE CYCLE OF CONCERN WILL BE THIS EVENING AS SPOTTY
MINOR TO WIDESPREAD MINOR TIDAL FLOODING IS FORECAST FOR ATLANTIC
COASTAL AREAS AS WELL AS PORTIONS OF THE DELAWARE BAY. WATER LEVELS
LOOK TO PEAK EVEN HIGHER BY WEDNESDAY EVENING. AS A RESULT, WE
EXTENDED THE COASTAL FLOOD ADVISORY IN EFFECT FOR OCEAN COUNTY NJ
SOUTH THROUGH SUSSEX AND KENT COUNTIES IN DELAWARE THROUGH WEDNESDAY
EVENING. WE ALSO ADDED NEW CASTLE DE AND SALEM COUNTY NJ IN THE
ADVISORY FOR WEDNESDAY EVENING. IN SOME OF THE BACK BAYS, MODERATE
COASTAL FLOODING IS POSSIBLE WITH WEDNESDAY EVENING'S HIGH TIDE
CYCLE. BUT GIVEN FLUCTUATING FORECASTS, DID NOT QUITE HAVE THE
CONFIDENCE TO ISSUE A COASTAL FLOOD WATCH. BEYOND WEDNESDAY EVENING,
THE NOR'EASTER WILL GRADUALLY BE MOVING AWAY FROM THE REGION FOR THE
END OF THE WEEK. ANOTHER ROUND OF COASTAL FLOODING IS POSSIBLE
THURSDAY EVENING WITH SPOTTY MINOR TO WIDESPREAD MINOR COASTAL
FLOODING. THIS HIGH TIDE CYCLE IS FORECAST TO BE LOWER THAN
WEDNESDAY EVENING'S HIGH TIDE CYCLE.
AT THIS TIME WE ARE NOT FORECASTING ANY COASTAL FLOODING FOR THE
MARYLAND EASTERN SHORE.
KEY MESSAGE 3...FROST IMPACTS POSSIBLE FRIDAY NIGHT AND SATURDAY
NIGHT WHERE THE GROWING SEASON CONTINUES.
AS AN UPPER-LEVEL TROUGH PIVOTS ACROSS THE NORTHEAST ON FRIDAY, A
POTENTIALLY STRONG MID LEVEL RIDGE IN THE PLAINS TO MIDWEST SHIFTS
EASTWARD SOME INTO THE WEEKEND. THIS WILL SUPPORT STRONG SURFACE
HIGH PRESSURE INITIALLY CENTERED NEAR THE GREAT LAKES, WHICH THEN
SHIFTS EASTWARD INTO THE NORTHEAST AND MID-ATLANTIC FRIDAY AND OVER
THE WEEKEND.
A CHILLY AND DRY AIR MASS WILL ACCOMPANY THIS STRONG SURFACE HIGH,
AND AS THE HIGH ITSELF SETTLES MORE OVERHEAD THE WINDS WILL DECOUPLE.
THIS WILL SET THE STAGE FOR EFFICIENT RADIATIONAL COOLING BOTH FRIDAY
NIGHT AND SATURDAY NIGHT. THE FORECAST LOWS, AS OF NOW, ARE IN THE
30S FOR MUCH OF THE AREA (AWAY FROM THE COASTS AND OUTSIDE OF THE
URBAN CENTERS) WITH A FROST POTENTIAL. IT IS POSSIBLE THAT IF THE
RADIATIONAL COOLING ENDS UP BEING STRONGER, THEN SOME AREAS
COULD GET TO FREEZING OR A LITTLE BELOW. OVERALL THOUGH, FROST
IMPACTS ARE POSSIBLE WHERE THE GROWING SEASON REMAINS ACTIVE.
AVIATION /19Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON...VFR. NORTH-NORTHEAST WINDS 10-15 KNOTS WITH
GUSTS TO 25 KNOTS. MODERATE CONFIDENCE.
TONIGHT...VFR. NORTH-NORTHEAST WINDS DIMINISH TO 10 KNOTS OR LESS
FOR A TIME, THEN SHOULD INCREASE WITH SOME GUSTS TO 20 KNOTS
ESPECIALLY AT KACY. MODERATE CONFIDENCE.
WEDNESDAY...VFR. NORTH-NORTHEAST WINDS 10-15 KNOTS WITH GUSTS 20-30
KNOTS, WITH THE STRONGEST WINDS MAINLY AT KACY AND KMIV. GUSTS COULD
BE LIMITED AT KABE AND KRDG. MODERATE CONFIDENCE.
OUTLOOK...
WEDNESDAY NIGHT AND THURSDAY...VFR. NORTH-NORTHWEST WIND GUSTS TO 20
KNOTS POSSIBLE ON THURSDAY.
FRIDAY THROUGH SUNDAY...VFR.
MARINE
THE PRESSURE GRADIENT BETWEEN STRENGTHENING LOW PRESSURE WELL OFF
THE MID-ATLANTIC COAST AND STRONG HIGH PRESSURE INTO NEW ENGLAND
WILL TIGHTEN INTO WEDNESDAY. THE WIND INCREASE HAS CONTINUED TO BE
SLOWER THAN ANTICIPATED SO FAR TODAY. OPTED TO MAINTAIN THE EXISTING
GALE WARNING FOR NEARLY ALL OF THE ATLANTIC COASTAL WATERS AND
ADJACENT OFFSHORE ZONES AS GUIDANCE SHOWS GALE FORCE WIND GUSTS
DEVELOPING TONIGHT AND FOR A TIME WEDNESDAY. SMALL CRAFT ADVISORY
CONDITIONS DEVELOP ON DELAWARE BAY THROUGH TONIGHT. SEAS WILL
CONTINUE TO BE HAZARDOUS. PEAK WINDS ACROSS OUR WATERS ARE FORECAST
TO BE BETWEEN 30 KNOTS AND 45 KNOTS.
OUTLOOK...
WEDNESDAY NIGHT AND THURSDAY...GALES FOR MUCH OF THE OCEAN WATER
ZONES, WITH SMALL CRAFT ADVISORY CONDITIONS ON DELAWARE BAY. THE
WINDS ARE EXPECTED TO DIMINISH WEDNESDAY NIGHT AND ESPECIALLY
THURSDAY. HAZARDOUS SEAS WILL CONTINUE BUT GRADUALLY SUBSIDE.
FRIDAY...SMALL CRAFT ADVISORY CONDITIONS PROBABLE.
SATURDAY...WINDS ARE FORECAST TO BE BELOW SMALL CRAFT ADVISORY
CRITERIA, HOWEVER SEAS 5-7 FEET MAY LINGER FOR A WHILE LONGER
FOR THE ATLANTIC COASTAL WATERS.
SUNDAY...THE CONDITIONS SHOULD BE BELOW SMALL CRAFT ADVISORY
CRITERIA.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT WEDNESDAY FOR
NJZ016.
COASTAL FLOOD ADVISORY UNTIL 10 PM EDT WEDNESDAY FOR NJZ020-
022>027.
COASTAL FLOOD ADVISORY FROM 4 PM TO 10 PM EDT WEDNESDAY FOR
NJZ021.
DE...COASTAL FLOOD ADVISORY FROM 6 PM TO 10 PM EDT WEDNESDAY FOR
DEZ001.
COASTAL FLOOD ADVISORY UNTIL 10 PM EDT WEDNESDAY FOR
DEZ002>004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT WEDNESDAY FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ450.
GALE WARNING UNTIL 6 PM EDT WEDNESDAY FOR ANZ451>455-480.
GALE WARNING UNTIL 6 AM EDT THURSDAY FOR ANZ481>483-485.
DISCUSSION...FITZSIMMONS/GORSE/GUZZO/RCM
AVIATION...GORSE
MARINE...GORSE
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