828
FXUS61 KPHI 300753
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
353 AM EDT SUN MAR 30 2025
SYNOPSIS
A FRONT WILL REMAIN STALLED ACROSS THE AREA THROUGH MUCH OF
SUNDAY. THIS FRONT FINALLY LIFTS BACK TO THE NORTHEAST ONCE AND
FOR ALL SUNDAY NIGHT INTO EARLY MONDAY, BEFORE A MORE POWERFUL
FRONT MOVES INTO THE REGION FROM THE NORTHWEST MONDAY NIGHT.
HIGH PRESSURE RETURNS TUESDAY AND WEDNESDAY BEFORE A MORE ACTIVE
WEATHER PATTERN ARRIVES FOR THE END OF THE WEEK INTO NEXT
WEEKEND.
NEAR TERM /THROUGH TONIGHT/
A MIXED BAG OF WEATHER CONDITIONS ACROSS THE REGION TODAY. A
STALLED FRONTAL BOUNDARY WILL MAKE FOR A VERY CHALLENGING
TEMPERATURE FORECAST. DELMARVA WILL EXPERIENCE ANOTHER VERY WARM
DAY WITH TEMPERATURES WELL INTO THE 70S TO NEAR 80 DEGREES AND
SOME BREAK OF SUNSHINE. AREAS FROM NEAR THE PHILLY METRO NORTH
AND EAST, INCLUDING ALONG COASTAL NEW JERSEY, WILL REMAIN UNDER
THE INFLUENCE OF A MUCH COOLER MARINE LAYER, KEEPING
TEMPERATURES NEAR 15 TO 25 DEGREES COOLER THAN SATURDAY ALONG
WITH CLOUDY SKIES.
BROAD UPPER RIDGING WILL SLOWLY PASS ACROSS THE REGION TODAY,
SHIFTING EAST INTO TONIGHT AS A SHORTWAVE TROUGH APPROACHES FROM
THE WEST. AT THE SURFACE, HIGH PRESSURE WILL REMAIN CENTERED
NEAR BERMUDA AS A SURFACE LOW DEVELOPS ACROSS THE GREAT LAKES.
LOCALLY, A STALLED (SLOWLY MOVING) FRONTAL BOUNDARY WILL BISECT
THE AREA TODAY FROM SOUTHEAST PA INTO SOUTHERN NJ. THIS BOUNDARY
WILL EVENTUALLY START SURGING NORTHWARD OVERNIGHT AS A WARM
FRONT, EVENTUALLY LIFTING NORTH OF I-80 BY DAWN MONDAY.
THE BIGGEST CHALLENGE FOR TODAY WILL UNDOUBTEDLY BE THE
TEMPERATURE FORECAST. A BIG "BOOM OR BUST" TEMPERATURE DAY FOR
THOSE IN THE VICINITY OF THE FRONTAL BOUNDARY. THE FRONTAL
BOUNDARY HAS MADE IT MUCH FARTHER SOUTH, AND WITH MUCH MORE
POTENCY THAN PREVIOUSLY EXPECTED. GIVEN THIS TREND, THE HIGH
TEMPERATURE FORECAST WAS LOWERED BY SEVERAL DEGREES FOR AREAS
NEAR, NORTH, AND EAST OF THE PHILLY METRO. DELMARVA SHOULD
EASILY CLIMB BACK INTO THE UPPER 70S TO NEAR 80 DEGREES AGAIN.
THE GENERAL CONSENSUS ON THE NORTHWARD PROGRESS OF THE FRONTAL
BOUNDARY IS FOR IT TO LIFT TO NEAR A LINE FROM BETWEEN READING
AND ALLENTOWN, TO BETWEEN PHILLY AND TRENTON, TO JUST NORTH OF
ATLANTIC CITY. NORTHEAST OF THE BOUNDARY WILL EXPERIENCE A
CLOUDY AND COOL TO MILD DAY, WITH TEMPERATURES MAINLY IN THE 40S
AND 50S. WHERE EVER THE BOUNDARY STALLS OUT SHOULD SEE
TEMPERATURES EVENTUALLY REACHING INTO THE 60S BY MID TO LATE
AFTERNOON. SOUTHWEST OF THE BOUNDARY WILL BE IN THE 70S. LONG
STORY SHORT, A LOW CONFIDENCE TEMPERATURE FORECAST FOR THE
CENTRAL PART OF THE FORECAST AREA. PHILLY WILL BE LUCKY TO REACH
70 DEGREES TODAY.
THE WIND FORECAST IS ALSO TRICKY, THOUGH LESS MEANINGFUL THAN
TEMPERATURES. SOUTH OF THE FRONT WILL TURN BREEZY AGAIN BY
AFTERNOON, WITH SOUTHERLY WINDS 10-15 MPH AND GUSTS NEAR 25 MPH.
NEAR AND NORTH OF THE BOUNDARY WILL SEE EAST TO SOUTHEAST WINDS
AROUND 10 MPH.
THE DAYTIME PERIOD SHOULD BE MAINLY DRY, THOUGH CAN'T
COMPLETELY RULE OUT A STRAY SHOWER OF SPRINKLE.
FOR TONIGHT, THE FRONTAL BOUNDARY WILL GRADUALLY START LIFTING
NORTH. THIS WILL BE AIDED BY A STRENGTHENING SOUTHERLY PRESSURE
GRADIENT AND THE APPROACHING SHORTWAVE TROUGH. AREAS NORTH OF
THE BOUNDARY WILL SEE TEMPERATURES BEGINNING TO INCREASE
OVERNIGHT. GENERALLY A VERY MILD NIGHT WITH LOW TEMPERATURES
SOUTH OF THE FRONT NEAR 60 DEGREES, AND NEAR 50 DEGREES NORTH OF
THE FRONT. THERE WILL BE INCREASING CHANCES FOR SHOWERS
OVERNIGHT WITH THE APPROACHING TROUGH, THOUGH NOTHING OF ANY
SIGNIFICANCE. SOUTHERLY WINDS INCREASING TO 10-15 MPH OVERNIGHT,
WITH SOME GUSTS NEAR 25 MPH POSSIBLE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
A STRONG COLD FRONT WILL APPROACH THE AREA MONDAY AFTERNOON AND
PUSH THROUGH MONDAY NIGHT. THERE ARE STILL SOME DIFFERENCES IN
THE FORECAST MODELS REGARDING THE EXACT TIMING BUT NOT AS MUCH
AS BEFORE AND IT GENERALLY LOOKS LIKE THE FRONT SHOULD BE MOVING
THROUGH WEST TO EAST SOMETIME IN THE LATE EVENING INTO THE
EARLY OVERNIGHT HOURS. AREAS NORTH AND WEST OF THE I-95 CORRIDOR
LOOK TO SEE THE HEAVIEST RAIN AND THUNDERSTORMS NEAR AND ALONG
THE FRONTAL BOUNDARY BEGINNING MID/LATE AFTERNOON INTO THE
EVENING WITH AREAS SOUTH AND EAST EXPECTED TO SEE MOST OF THE
IMPACTS MAINLY AFTER SUNSET, MAINLY IN THE 8 PM TO 2 AM
TIMEFRAME. WE COULD ALSO SEE SOME PRE-FRONTAL SHOWERS AND
THUNDERSTORMS AHEAD OF THIS LINE THROUGHOUT THE AFTERNOON,
THOUGH THERE STILL REMAINS SOME UNCERTAINTY WITH THE COVERAGE.
SKIES ARE EXPECTED TO BE MOSTLY CLOUDY MONDAY BUT TEMPERATURES
ARE STILL FORECAST TO WARM INTO THE LOW TO MID 70S. THE CLOUDY
SKIES WILL ALSO HELPING LIMIT DAYTIME HEATING AND OVERALL
INSTABILITY WITH MUCAPE VALUES LARGELY LESS THAN 1000 J/KG.
HOWEVER, THERE WILL BE VERY STRONG DYNAMICS AND SHEAR IN PLACE,
SO MUCH OF THE AREA REMAINS IN A SLIGHT RISK OF SEVERE WEATHER
FROM THE STORM PREDICTION CENTER, MAINLY FOR DAMAGING WIND GUSTS
WITHIN SEVERE THUNDERSTORMS. IT IS ALSO WORTH NOTING, HOWEVER,
THAT THE 0-1 KM SHEAR AND HELICITY LOOK TO BE QUITE HIGH SO A
TORNADO OR TWO WILL BE POSSIBLE. CONFIDENCE ON THIS IS LOWER
THOUGH. THE BEST CHANCE FOR SOME SEVERE WEATHER WILL COME DURING
THE AFTERNOON AND EARLY EVENING WHILE THE HEAVY RAIN THREAT
WILL BE HIGHEST THROUGH THE MID TO LATE EVENING INTO THE EARLY
OVERNIGHT HOURS AS STORMS TEND TO GROW UPSCALE AND INSTABILITY
BECOMES MORE ELEVATED. A STRENGTHENING LOW- LEVEL JET DURING THE
EVENING AND NIGHTTIME HOURS WILL SUPPORT PWAT VALUES SURGING
INTO THE 1.5+ INCH RANGE, NEAR THE CLIMATOLOGICAL MAXIMUM FOR
THIS TIME OF YEAR. AS A RESULT, FORECASTED STORM TOTAL RAINFALL
WILL BE AROUND 0.75-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. DESPITE OUR ONGOING DROUGHT, THERE ARE LOCALIZED
FLOODING CONCERNS, ESPECIALLY DUE TO POTENTIAL RAINFALL RATES
CAUSING SOME LOCALIZED URBAN FLOODING. ONCE THE COLD FRONT
PUSHES THROUGH, OVERNIGHT LOWS WILL COOL DOWN INTO THE 40S WITH
EVEN SOME 30S OVER THE POCONOS AND NW NJ.
THE COLD FRONT WILL PUSH OFFSHORE EARLY TUESDAY MORNING, GIVING
WAY TO BUILDING HIGH PRESSURE FOR TUESDAY. A SURGE OF NW WINDS
BEHIND THE FRONT CAN BE EXPECTED AFTER DAYBREAK TUESDAY WITH
GUSTS 20-30 MPH POSSIBLE, BEFORE BEGINNING TO SUBSIDE DURING THE
AFTERNOON. INCREASINGLY SUNNY SKIES TUESDAY WITH SEASONABLE
TEMPERATURES MAINLY IN THE UPPER 40S TO UPPER 50S FOR HIGHS.
A COLD CANADIAN AIR MASS BUILDS OVERHEAD FOR TUESDAY NIGHT WITH
REDUCING WINDS, SO MOST AREAS AWAY FROM THE COAST AND MARINE
WATERS MAY BE NEAR OR BELOW FREEZING. DEPENDING ON HOW IT PLAYS
OUT, MIGHT NEED FROST ADVISORIES OR FREEZE WARNINGS FOR THE
DELMARVA SOUTH OF WILMINGTON, WHERE THE GROWING SEASON IS
DEFINED TO BEGIN ON APRIL 1, THOUGH AT THIS MOMENT WE ARE STILL
NOT FORECASTING TEMPS TO DROP QUITE THAT MUCH.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
WEDNESDAY STARTS WITH SOME PARTIAL SUN, THEN CLOUDS INCREASE AS
THE NEXT SYSTEM APPROACHES. HIGHS WILL BE IN THE 50S FOR MOST.
A MORE ACTIVE WEATHER PATTERN IS EXPECTED FOR THE LATTER HALF
OF THE WEEK THROUGH NEXT WEEKEND. AN INITIAL LOW LOOKS TO MOVE
BY NORTH OF THE AREA THURSDAY INTO THURSDAY NIGHT. THE STEADIEST
PRECIP WITH THIS SYSTEM SHOULD STAY TO THE NORTH HOWEVER THERE
STILL WILL BE AT LEAST CHANCES FOR SOME SHOWERS FIRST WITH THE
SYSTEM'S WARM FRONT AND THEN WITH ITS COLD FRONT. THE COLD FRONT
WITH THE SYSTEM THEN LOOKS TO STALL NEAR OR JUST SOUTH OF THE
AREA FRIDAY WHICH WILL KEEP CHANCES OF SHOWERS IN THE FORECAST.
ONE OR MORE ADDITIONAL WAVES OF LOW PRESSURE THEN LOOK TO MOVE
THROUGH ALONG THIS FRONT NEXT WEEKEND KEEPING THINGS GENERALLY
UNSETTLED WITH CHANCES FOR RAIN/SHOWERS. AS FOR TEMPERATURES,
THURSDAY LOOKS TO BE QUITE WARM WITH HIGHS MAINLY IN THE 70S. IT
WILL THEN TREND COOLER FRIDAY INTO NEXT WEEKEND WITH HIGHS NEXT
WEEKEND LOOKING TO BE MAINLY IN THE UPPER 50S TO LOW 60S.
AVIATION /07Z SUNDAY THROUGH THURSDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...MVFR TO IFR CEILINGS. HIGH CONFIDENCE IN
PREVAILING CONDITIONS, EXCEPT FOR RDG, ILG, AND MIV, WHICH HAVE
YET TO DEVELOP THE LOWER CEILINGS. NORTHEAST TO EAST WINDS NEAR
5-10 KTS.
TODAY...WHERE CEILINGS EXIST BY 12Z, THEY WILL BE SLOW TO
SCATTER OUT OR LIFT TO VFR. IMPROVEMENT SHOULD BEGIN TO OCCUR BY
15-18Z. TTN, ABE, AND PNE MAY NOT IMPROVE TO VFR AT ALL. EAST
TO SOUTHEAST WINDS 5-10 KTS. LOW CONFIDENCE ON TIMING OF
IMPROVEMENTS TODAY.
TONIGHT...MVFR TO VFR CEILINGS. GUIDANCE INDICATES SOME MVFR
CEILINGS MAY DEVELOP BETWEEN 03-09Z FOR TERMINALS THAT ARE
INITIALLY VFR, BUT LOW CONFIDENCE ON THIS. SOUTHEAST TO SOUTH
WINDS 5-10 KTS, INCREASING SOME BY 06Z WITH SOME GUSTS NEAR
20-25 KTS POSSIBLE. LLWS POSSIBLE, ESPECIALLY EARLY, WITH 2KFT
WINDS NEAR 40 KTS FROM THE SOUTH.
OUTLOOK...
MONDAY AND MONDAY NIGHT...SUB-VFR CONDITIONS DEVELOPING IN THE
AFTERNOON THROUGH THE OVERNIGHT WITH A FRONTAL PASSAGE. HEAVY
RAIN AND THUNDERSTORMS LIKELY. GUSTY WINDS 20-25 KTS.
TUESDAY THROUGH WEDNESDAY...VFR. BREEZY EARLY TUESDAY MORNING.
THURSDAY...SUB-VFR CONDITIONS POSSIBLE WITH SHOWERS LATE.
MARINE
ADVISORY CONDITIONS THROUGH 6 AM NEAR AND NORTH OF ATLANTIC
CITY DUE TO ELEVATED SEAS. BEYOND THAT, NO MARINE HAZARDS ARE
EXPECTED TODAY. LOW CLOUDS AND PATCHY FOG POSSIBLE NORTH OF
ATLANTIC CITY. WINDS 5- 10 KTS, SETTLING OUT OF THE SOUTH AND
INCREASING TO 15-20 KTS INTO THE AFTERNOON FROM SOUTH TO NORTH.
SEAS 3-4 FEET.
FOR TONIGHT, SOUTHERLY WINDS INCREASING TO 15-25 KTS WITH SEAS
BUILDING TO 4-6 FEET. A NEW SMALL CRAFT ADVISORY WILL BE ISSUED
FOR TONIGHT WHEN THE CURRENT ONE EXPIRES. SOME FOG DEVELOPMENT
POSSIBLE LATE TONIGHT.
OUTLOOK...
SCA CONDITIONS PREVAILING MONDAY THROUGH TUESDAY MORNING.
SOUTHERLY WINDS RAMP UP TO 25-30 KTS AHEAD OF A COLD FRONT INTO
MONDAY WITH SEAS BUILDING TO 5-7 FEET. WINDS SHIFT TO
NORTHWESTERLY BEHIND THE FRONT MONDAY NIGHT WITH GUSTS STILL
AROUND 25KTS AND SEAS 5-7 FEET EARLY TUESDAY. WINDS AND SEAS
DIMINISH TUESDAY, FALLING BELOW SCA CRITERIA LATE DAY. SCA
CONDITIONS GRADUALLY RETURN WEDNESDAY NIGHT INTO THURSDAY.
TIDES/COASTAL FLOODING
FOR THE SUNDAY NIGHT HIGH TIDE, MANY SITES ALONG THE NJ
ATLANTIC COAST AND SOUTHERN SHORES OF THE RARITAN BAY ARE LIKELY
TO GET CLOSE TO OR OVER MINOR FLOOD STAGE AS ASTRONOMICAL TIDES
REMAIN HIGH. THE BIGGEST CONCERN AT THIS POINT IS FOR TIDAL
LOCATIONS IN MIDDLESEX AND MONMOUTH COUNTIES AND FOR THIS REASON
WE'VE ISSUED A COASTAL FLOOD ADVISORY FOR THESE AREAS.
ELSEWHERE ON THE ATLANTIC COAST, DELAWARE BAY, AND TIDAL
DELAWARE RIVER, TIDE LEVELS ARE FORECAST TO BE NEAR BUT JUST
BELOW ADVISORY THRESHOLDS.
ON THE NORTHEASTERN CHESAPEAKE BAY, TIDAL FLOODING ISN'T
EXPECTED DUE TO LOWER ASTRONOMICAL TIDES.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
MONDAY FOR NJZ012>014.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
ANZ450>452.
SYNOPSIS...FITZSIMMONS/MJL
NEAR TERM...AKL/JOHNSON/STAARMANN
SHORT TERM...FITZSIMMONS/MJL
LONG TERM...FITZSIMMONS/MJL
AVIATION...FITZSIMMONS/STAARMANN
MARINE...FITZSIMMONS/STAARMANN
TIDES/COASTAL FLOODING...
CLIMATE...
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