031
FXUS61 KPHI 170919
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
519 AM EDT WED SEP 17 2025
SYNOPSIS
A COASTAL LOW LOCATED OVER THE MOUTH OF THE CHESAPEAKE WILL
REMAIN NEARLY STATIONARY TODAY WHILE WEAKENING BEFORE TRACKING
SLOWLY NORTHEASTWARD OFF THE COAST BY THURSDAY. A COLD FRONT
WILL PASS THROUGH THE AREA ON FRIDAY, FOLLOWED BY STRONG HIGH
PRESSURE WHICH WILL BE IN CONTROL THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
A WEAKENING COASTAL STORM WILL LINGER ACROSS OUR REGION INTO
TONIGHT. THIS WILL RESULT IN CLOUDY SKIES, BELOW NORMAL
TEMPERATURES, CONTINUING NORTHEAST TO EAST WINDS, AND PERIODS OF
SHOWERS FOR MUCH OF THE DAY. THE WINDS AND SHOWERS WILL LESSEN INTO
TONIGHT WITH LINGERING LOW CLOUDS AND SOME FOG POSSIBLE.
A BROAD, CLOSED UPPER TROUGH WILL DEAMPLIFY AND OPEN, EVENTUALLY
EJECTING NORTHEAST INTO TONIGHT. AT THE SURFACE, WEAKENING HIGH
PRESSURE ACROSS NEW ENGLAND WILL GRADUALLY PUSH TOWARD THE CANADIAN
MARITIMES. MEANWHILE, THE COASTAL LOW WILL REMAIN IN THE VICINITY OF
OUR REGION WHILE WEAKENING, THEN EVENTUALLY SHIFT OFFSHORE INTO
TONIGHT.
BANDS OF SHOWERS WILL CONTINUE TO IMPACT THE REGION TODAY, GENERALLY
MOVING INLAND AND GRADUALLY LIFTING TOWARD THE NORTH AS THE DAY
PROGRESSES. THE GREATEST CHANCES OF RAIN (60-80%) WILL BE MAINLY
ALONG AND SOUTH OF I-78. THE RAIN WILL BE SHOWERY IN NATURE, NOT
REALLY AN "ALL DAY RAIN" TYPE OF SITUATION, RATHER PERIODS OF LIGHT
TO MODERATE SHOWERS AT TIMES. SOME ELEVATED INSTABILITY WILL BE
PRESENT, WITH MUCAPE VALUES OF A FEW HUNDRED J/KG POSSIBLE ACROSS
THE COASTAL PLAIN ESPECIALLY. THIS COULD RESULT IN SOME THUNDER WITH
AN MORE ROBUST CONVECTION THAT DEVELOPS. NO SEVERE THUNDERSTORMS ARE
EXPECTED, BUT THE HEAVIER SHOWERS OR STORMS COULD HELP MIX DOWN
BRIEFLY STRONGER WIND GUSTS AROUND 30 MPH. GIVEN THE RECENT DRYNESS
AND HEAVIER RAINFALL OCCURRING OVER THE SANDY COASTAL PLAIN, NO
FRESH WATER FLOOD THREAT IS EXPECTED.
QPF IS AROUND 0.5-1" OF RAIN FOR THE COASTAL PLAIN SOUTHEAST OF I-
95. NORTH AND WEST OF I-95, QPF IS MAINLY 0.1-0.25" AT MOST. THE
UNCERTAINTY LIES IN THE MIDDLE RIGHT AROUND THE I-95 CORRIDOR, WHICH
SHOULD EXPERIENCE 0.25" OR SO, BUT SOME AREAS MAY SEE A LITTLE MORE
OR LESS THAN THAT.
NORTHEAST WINDS WILL BE NEAR 10-20 MPH THROUGH MUCH OF THE DAY, WITH
GUSTS NEAR 25 MPH POSSIBLE. TEMPERATURES WILL REMAIN NEARLY STEADY
IN THE UPPER 60S TO LOW 70S. LOWS TONIGHT IN THE MID 50S TO MID 60S.
LOW CLOUDS WILL LINGER TONIGHT AND SOME FOG DEVELOPMENT IS POSSIBLE.
WINDS WILL SHIFT MORE NORTHERLY NEAR 5-10 MPH TONIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
BY THURSDAY MORNING, THE SUB-TROPICAL LOW WILL BE NOTHING MORE THAN
AN OPEN TROUGH AS IT MOVES FURTHER OUT TO SEA. SOME LINGERING
SHOWERS MAY STILL OCCUR NEAR THE COAST IN THE MORNING, BUT OVERALL
SHOULD SEE DRASTIC IMPROVEMENTS FOR ALL AREAS BY THE AFTERNOON WITH
CLEARING SKIES. HIGH TEMPERATURES WILL VARY FROM THE MID TO UPPER
70S FOR COASTAL AREAS, WITH LOW TO MID 80S ACROSS THE I-95 CORRIDOR
AND POINTS NORTH AND WEST. CLEAR SKIES AND BENIGN WEATHER WILL
CONTINUE INTO THURSDAY NIGHT WHERE LOW TEMPERATURES ARE EXPECTED TO
FALL INTO THE MID 50S TO LOW 60S.
FRIDAY LOOKS TO BE A PRETTY NICE DAY OVERALL WITH A BRIEF RETURN OF
SUMMER-LIKE TEMPERATURES. HIGHS ARE EXPECTED TO TOP OUT IN THE LOW
TO MID 80S ACROSS THE ENTIRE REGION, OUTSIDE OF THE HIGHER TERRAIN
WHICH WILL BE IN THE UPPER 70S. THE IS ONE FEATURE TO NOTE THOUGH,
WHICH IS A COLD FRONT THAT WILL APPROACH THE AREA FROM THE NORTH AS
THE DAY PROGRESSES. DEPENDING ON FORWARD PROGRESSION OF THE FRONT,
AREAS NORTH AND WEST MAY END UP A FEW DEGREES COOLER THAN CURRENTLY
FORECAST. NO PRECIPITATION IS EXPECTED THOUGH AS THE ATMOSPHERIC
COLUMN LACKS ANY MOISTURE, SO SKIES ARE ANTICIPATED TO BE MOSTLY
SUNNY ON FRIDAY. BEHIND THE FRONT THOUGH, THERE WILL BE A STRONG
PUSH OF COLD AIR ADVECTION AND DRIER AIR THAT WILL POUR INTO THE
REGION BY FRIDAY NIGHT. THIS WILL LEAD TO LOWS BOTTOMING OUT IN THE
50S FOR MOST, 40S ACROSS THE HIGHER TERRAIN AND 60S NEAR THE
COAST.
LONG TERM /SATURDAY THROUGH TUESDAY/
THE LONG TERM PERIOD FOR THE WEEKEND AND INTO EARLY NEXT WEEK WILL
LARGELY BE DOMINATED BY STRONG HIGH PRESSURE ORIGINATING FROM
CANADA. THE CENTER OF THIS HIGH WILL SETTLE OVER QUEBEC ON SATURDAY,
SHIFTING SOUTHEAST INTO THE CANADIAN MARITIMES ON SUNDAY, WITH
RIDGING STILL EXTENDING WEST INTO THE MID-ATLANTIC INTO THE
BEGINNING OF NEXT WEEK. THIS WILL YIELD A VERY NICE WEEKEND OVERALL,
WITH MOSTLY CLEAR SKIES AND LIGHT ONSHORE FLOW.
BY MONDAY AND TUESDAY, WILL BEGIN TO SEE SOUTHWESTERLY FLOW DEVELOP
ALOFT AS A DEEPENING TROUGH MOVES INTO THE HIGH PLAINS. WHILE THE
AREA WILL STILL BE UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE, WE
WILL BEGIN TO SEE A GRADUAL WARMING TREND AND THE RETURN OF ABOVE
NORMAL TEMPERATURES BY THE MIDDLE OF THE WEEK. WILL HAVE TO MONITOR
A STALLED BOUNDARY NEAR THE CAROLINA COAST ON TUESDAY, WHICH MAY
RESULT IN A FEW ISOLATED SHOWERS NEAR THE COAST. HOWEVER, THE
POTENTIAL OF THIS OCCURRENCE IS LOW THANKS TO STRONG RIDGING
REMAINING OVER MUCH OF THE MID-ATLANTIC.
AVIATION /09Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...CEILINGS LOWERING TO MVFR FROM SOUTH TO NORTH THROUGH
DAYBREAK. SOME LIGHT TO MODERATE SHOWERS MAY BRIEFLY CAUSE MVFR
VISIBILITY RESTRICTIONS. NE WINDS AROUND 10-15 KTS WITH GUSTS NEAR
20-25 KTS POSSIBLE FROM NEAR I-95 AND SOUTHEAST TO THE COAST.
MODERATE CONFIDENCE ON TIMING OF MVFR RESTRICTIONS.
TODAY..GENERALLY PREVAILING LOW END MVFR CEILINGS, WITH IFR POSSIBLE
AT TIMES. BANDS OF SHOWERS WILL PASS THROUGH THE REGION, RESULTING
IN MVFR TO IFR VISIBILITY AT TIMES. SOME ISOLATED THUNDERSTORMS
POSSIBLE, BUT PROBABILITY IS TOO LOW TO INCLUDE A TAF MENTION AT
THIS TIME. SOME FOG DEVELOPMENT IS POSSIBLE AS WELL. NE WINDS 10-15
KTS PEAKING THIS MORNING, THEN GRADUALLY LESSENING AFTER 18Z. GUSTS
NEAR 20-25 KTS EARLY, MAINLY FROM NEAR I-95 AND SOUTHEAST TOWARD THE
COAST. MODERATE CONFIDENCE OVERALL, BUT LOW CONFIDENCE ON THE
DETAILS OUTLINED IN THE TAFS.
TONIGHT...IFR CEILINGS EXPECTED, WITH SOME IMPROVEMENT POSSIBLE
LATE. NORTH TO NORTHEAST WINDS NEAR 5-10 KTS. LOW CONFIDENCE.
OUTLOOK...
THURSDAY...LINGERING SUB-VFR CONDITIONS EXPECTED IN THE MORNING WITH
A CHANCE OF SHOWERS. ALL TERMINALS SHOULD IMPROVE TO VFR IN THE
AFTERNOON WITH CLEARING SKIES.
THURSDAY NIGHT THROUGH SUNDAY...VFR. NO SIGNIFICANT WEATHER
EXPECTED.
MARINE
THE GALE WARNING WAS EXTENDED UNTIL 7 AM, AS GALE FORCE WIND GUSTS
CONTINUE WITHIN THE WARNING AREA. THESE SHOULD GRADUALLY SUBSIDE
THROUGH DAYBREAK. ELSEWHERE, A SMALL CRAFT ADVISORY IS IN EFFECT
THROUGH 2 PM FOR UPPER DELAWARE BAY AND THROUGH MIDNIGHT FOR THE
ATLANTIC COASTAL WATERS.
NORTHEAST TO EAST WINDS WILL GRADUALLY LESSEN THROUGH THE REMAINDER
OF THE MORNING. SEAS WILL ALSO LESSEN THROUGH THE REMAINDER OF THE
DAY, BUT WILL REMAIN NEAR 5 FEET OR MORE THROUGH MIDNIGHT OR SO
ACROSS THE ATLANTIC COASTAL WATERS. OVERNIGHT, WINDS WILL SHIFT
NORTHERLY AROUND 10-15 KTS WITH SEAS CONTINUING TO DIMINISH. PERIODS
OF SHOWERS AND A FEW THUNDERSTORMS THROUGH THIS AFTERNOON. SOME FOG
MAY ALSO CAUSE SOME VISIBILITY RESTRICTIONS AT TIMES.
OUTLOOK...
THURSDAY THROUGH FRIDAY...NO MARINE HEADLINES EXPECTED. LINGERING
SHOWERS EXPECTED ON THURSDAY, OTHERWISE FAIR WEATHER.
FRIDAY NIGHT THROUGH SATURDAY...SCA CONDITIONS POSSIBLE MAINLY DUE
TO WIND GUSTS UP TO 25 KT. SEAS AROUND 3-4 FEET.
SATURDAY NIGHT THROUGH SUNDAY...NO MARINE HEADLINES EXPECTED. FAIR
WEATHER.
RIP CURRENTS...
FOR TODAY, EAST-NORTHEAST WINDS AROUND 15-25 MPH WITH LOCALLY
HIGHER GUSTS UP TO 30 MPH. BREAKING WAVES OF 3-6 FEET IN THE
SURF ZONE WITH AN EASTERLY SWELL AROUND 6-8 SECONDS. AS A
RESULT, HAVE MAINTAINED A HIGH RISK FOR THE DEVELOPMENT OF
DANGEROUS RIP CURRENTS FOR ALL BEACHES. THE RIP CURRENT
STATEMENT IS IN EFFECT THROUGH 8 PM TODAY.
FOR THURSDAY, NORTH-NORTHEAST WINDS AROUND 10-15 MPH. BREAKING
WAVE HEIGHTS OF 2-3 FEET. EASTERLY SWELL WILL PERSIST AROUND 6-8
SECONDS. GIVEN MORE SHORE PARALLEL WINDS AND DECREASING
SURF/WAVE HEIGHTS, HAVE OPTED TO MAINTAIN A MODERATE RISK FOR
THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR ALL BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
TIDES/COASTAL FLOODING
A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FOR SUSSEX COUNTY, DE
THROUGH 8 PM TONIGHT, MAINLY FOR THE BACK BAYS OF REHOBOTH BAY,
LITTLE ASSAWOMAN BAY, AND THE INDIAN RIVER BAY INLET WITH
TODAY'S HIGH TIDE CYCLES. ALSO, A COASTAL FLOOD ADVISORY HAS
ALSO BEEN ISSUED FOR OCEAN COUNTY, NJ WITH THESE EVENING'S HIGH
TIDE CYCLE FOR BOTH THE OCEAN FRONT AND THE BACK BAYS OF
BARNEGAT BAY. FUTURE EXTENSIONS OF ADVISORIES MAY BE WARRANTED,
DEPENDING ON HOW QUICKLY DRAINS OUT OF THE BACK BAYS.
ELSEWHERE ALONG THE OCEAN FRONT AND WITHIN THE LOWER DELAWARE
BAY, SPOTTY MINOR FLOODING IS POSSIBLE WITH EACH OF THE HIGH
TIDE CYCLES TODAY. CONFIDENCE IS NOT GREAT ENOUGH TO ISSUE
ADVISORIES FOR THESE LOCATIONS AT THIS TIME.
FOR THE UPPER DELAWARE BAY, TIDAL DELAWARE RIVER, AND THE
EASTERN SHORES OF THE CHESAPEAKE BAY, NO TIDAL FLOODING IS
EXPECTED THROUGH TONIGHT.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...HIGH RISK FOR RIP CURRENTS THROUGH THIS EVENING FOR NJZ014-024>026.
COASTAL FLOOD ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM EDT
THIS EVENING FOR NJZ020-026.
DE...COASTAL FLOOD ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DEZ003-
004.
HIGH RISK FOR RIP CURRENTS THROUGH THIS EVENING FOR DEZ004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ430.
GALE WARNING UNTIL 7 AM EDT THIS MORNING FOR ANZ431-453>455.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ450>452.
SYNOPSIS...DESILVA
NEAR TERM...STAARMANN
SHORT TERM...COOPER/DESILVA
LONG TERM...COOPER/DESILVA
AVIATION...DESILVA/STAARMANN
MARINE...DESILVA/STAARMANN
TIDES/COASTAL FLOODING...PHI
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page