038
FXUS61 KPHI 021750
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
150 PM EDT THU APR 2 2026
WHAT HAS CHANGED
WIDESPREAD FOG WILL DEVELOP TONIGHT WITH PATCHY DENSE FOG
LIKELY AROUND DAYBREAK FRIDAY.
KEY MESSAGES
1. STATIONARY BOUNDARY SOUTH OF THE DELMARVA PENINSULA WILL
LIFT NORTH AS A WARM FRONT LATE TONIGHT THROUGH FRIDAY MORNING.
CONDITIONS WARM UP FRIDAY AFTERNOON.
2. A WARM FRONT LIFTS NORTH OF THE REGION SATURDAY BEFORE A
COLD FRONT CROSSES THE REGION SUNDAY, BRINGING A FEW ROUNDS OF
SHOWERS AND THUNDERSTORMS BEFORE USHERING IN MORE SEASONABLE
TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...STATIONARY BOUNDARY SOUTH OF THE DELMARVA
PENINSULA WILL LIFT NORTH AS A WARM FRONT LATE TONIGHT THROUGH
FRIDAY MORNING. CONDITIONS WARM UP FRIDAY AFTERNOON.
HIGH PRESSURE REMAINS OVER EASTERN CANADA, AND ONSHORE FLOW
KEEPS A RELATIVELY COLD FOR THIS TIME OF THE YEAR AIRMASS OVER
THE AREA FOR THE REST OF THE DAY AND THROUGH TONIGHT. THIS HIGH
WILL MOVE OVER THE CANADIAN MARITIMES THIS EVENING BEFORE
DEPARTING FRIDAY MORNING. MEANWHILE, LOW PRESSURE OVER THE
MIDWEST WILL LIFT TO THE NORTH AND EAST TONIGHT INTO SOUTH-
CENTRAL CANADA. THIS LOW WILL TRACK ACROSS SOUTHERN CANADA ON
FRIDAY. A STATIONARY BOUNDARY EXTEND OUT FROM THIS LOW AND LIES
ACROSS THE MID-ATLANTIC, JUST SOUTH OF THE DELMARVA PENINSULA.
AS LOW PRESSURE LIFTS TO THE NORTH AND EAST, THEN EVENTUALLY TO
THE EAST, THAT STATIONARY BOUNDARY WILL BEGIN TO LIFT NORTH AS A
WARM FRONT LATE TONIGHT. THE WARM FRONT DOES NOT LOOK TO CLEAR
THE NORTHERN ZONES UNTIL LATE FRIDAY AFTERNOON.
IN TERMS OF SENSIBLE WEATHER, CONDITIONS REMAIN CLOUDY, COOL,
AND FOGGY FOR THE REST OF THE DAY AND INTO TONIGHT. ANOTHER WEAK
BOUNDARY OUT AHEAD OF THAT LOW WILL LIFT NORTH THROUGH THE
NORTHERN HALF OF THE FORECAST AREA, AND THIS MAY TOUCH OFF SOME
SHOWERS WITH MINIMAL QPF. WITH INCREASING LOW LEVEL MOISTURE AND
A STRONG INVERSION UP TO AROUND 950 MB, FOG AND STRATUS IS
LIKELY TO DEVELOP. THE TRUE SURGE IN LOW LEVEL MOISTURE ARRIVES
WITH THE PASSAGE OF THE MAIN WARM FRONT FRIDAY MORNING. HOWEVER,
IT DOES NOT LOOK AS IF THE INVERSION WILL BREAK UNTIL SOMETIME
FRIDAY AFTERNOON. AS A RESULT, CONDITIONS WILL REMAIN CLOUDY AND
FOGGY THROUGH MUCH OF FRIDAY MORNING, AND IT WILL TAKE SOME
TIME FOR TEMPERATURES TO WARM UP. LOOK FOR TEMPERATURES TO
REMAIN IN THE 40S AND 50S FOR MOST OF THE MORNING, NOT REALLY
WARMING UP UNTIL SKIES CLEAR OUT AND THE INVERSION BREAKS LATE
FRIDAY AFTERNOON. THERE COULD EVEN BE SOME PATCHY DENSE FOG JUST
AFTER SUNRISE AS WELL, AND A DENSE FOG ADVISORY MAY BE NEEDED
FOR A FEW HOURS FRIDAY MORNING. STRONG WARM AIR ADVECTION WILL
BE UNDERWAY LATE FRIDAY AFTERNOON. AND HIGHS WILL BE WELL IN THE
70S.
KEY MESSAGE 2...A WARM FRONT LIFTS NORTH OF THE REGION SATURDAY
BEFORE A COLD FRONT CROSSES THE REGION SUNDAY, BRINGING A FEW
ROUNDS OF SHOWERS AND THUNDERSTORMS BEFORE USHERING IN MORE
SEASONABLE TEMPERATURES.
A LOW PRESSURE SYSTEM WILL LIFT ACROSS THE GREAT LAKES ON
SATURDAY, LIFTING A WARM FRONT THROUGH THE REGION BEFORE A COLD
FRONT MOVES THROUGH ON SUNDAY, BRINGING A FEW ROUNDS OF SHOWERS
AND PERHAPS SOME THUNDERSTORMS. GLOBAL GUIDANCE CURRENTLY NOT
SHOWING TOO STRONG OF A SIGNAL FOR SEVERE WEATHER POTENTIAL WITH
THIS SYSTEM SATURDAY AND SUNDAY, BUT THIS CAN BE RATHER TYPICAL
GIVEN THE COARSE RESOLUTION OF THE GLOBAL GUIDANCE THIS FAR
OUT. AS A RESULT, ANY SEVERE POTENTIAL WILL HAVE TO BE MONITORED
AND REASSESSED OVER THE COMING DAYS AS REGIONAL AND HI RES
GUIDANCE GETS INTO RANGE OF THIS SYSTEM. ONE NOTABLE FACTOR
GLOBAL GUIDANCE IS DISPLAYING MORE CONFIDENTLY IS PWAT VALUES
WITH THIS SYSTEM REACHING CLOSE TO THE 1.3 TO 1.5 INCH RANGE
COME SUNDAY, WHICH WOULD BE NEAR THE CLIMATOLOGICAL MAXIMUM FOR
THIS TIME OF THE YEAR. CERTAINLY NO GUARANTEE THAT WE WILL SEE
CONCERNING LEVELS OF RAINFALL, BUT WE WILL ALSO NEED TO KEEP AN
EYE ON HOW STRONG THE DYNAMIC INVOLVED WITH THIS FRONTAL
BOUNDARY MAY EVOLVE OVER THE NEXT SEVERAL FORECAST RUNS. AT THE
MOMENT, MODEL CONSENSUS HAS A BROAD AREA OF ABOUT 0.50 INCHES OF
QPF FROM THIS SYSTEM.
THE WARM WEATHER OVER THE WEEKEND WITH UPPER 70S AND LOW 80S ON
SATURDAY WITH MID 60S TO LOW 70S ON SUNDAY WILL BREAK BEHIND THE
FRONT AS IT USHERS IN A MORE SEASONABLE AIRMASS. TEMPERATURES FOR
THE FIRST HALF OF NEXT WEEK WILL BE BACK NEAR OR SLIGHTLY BELOW
CLIMO FOR THIS TIME OF YEAR, WHICH TRANSLATES TO AFTERNOON HIGHS
LARGELY IN THE 50S ACROSS THE REGION.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...MOSTLY IFR CIGS IN LOW STRATUS WITH PATCHY MVFR
VSBYS IN BR. CIGS MAY LIFT TO MVFR (1000 TO 1500 FT) FROM TIME
TO TIME PRIOR TO 00Z, MAINLY AT KABE-KTTN-KPNE-KPHL. E WINDS 10
TO 15 KT WITH 20 TO 25 KT GUSTS. MODERATE CONFIDENCE.
TONIGHT...CIGS LOWER TO LIFR PRIOR TO 06Z. MVFR TO IFR VSBYS IN
BR FOR MOST OF THE NIGHT. VSBYS WILL DROP TO LESS THAN 1SM JUST
BEFORE 12Z. E WINDS 5 TO 10 KT, BECOMING LGT/VRB AFTER 09Z.
MODERATE CONFIDENCE.
FRIDAY...LOW CIGS AND VSBYS FOR MUCH OF THE MORNING, WITH VSBYS
LESS THAN 1SM AND CIGS LESS THAN 500 FT. CONDS IMPROVE BY 18Z,
AND SHOULD BE VFR BY 21Z. S WINDS 5 TO 10 KT IN THE MORNING,
INCREASING TO 10 TO 15 KT WITH GUSTS UP TO 20 KT AFTER 18Z.
MODERATE CONFIDENCE.
OUTLOOK...
FRIDAY NIGHT...PRIMARILY VFR.
SATURDAY THROUGH SATURDAY NIGHT...PRIMARILY VFR, BUT SUB-VFR
POSSIBLE IN ANY SHRA.
SUNDAY THROUGH SUNDAY NIGHT...SUB-VFR IN SHRA AND/OR TSRA.
MONDAY...VFR EXPECTED.
MARINE
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE OCEAN WATERS
FROM SANDY HOOK NJ TO GREAT EGG INLET, NJ, BUT HAS BEEN EXTENDED
TO 6 AM FRIDAY. THOUGH WINDS WILL DIMINISH THIS EVENING, SEAS
WILL REMAIN ELEVATED FOR MUCH OF TONIGHT.
E WINDS 15 TO 20 KT WITH 25 TO 30 KT GUSTS WITH 6 TO 8 FT SEAS
WHERE THE SCA IS IN EFFECT, WITH WINDS DIMINISHING TO AROUND 10
KT TONIGHT. SEAS SUBSIDE TO 3 TO 5 FT. OUTSIDE OF THE SCA, E
WINDS RANGE FROM 10 TO 15 KT WITH GUSTS UP TO 20 KT WITH 2 TO 4
FT SEAS. WINDS DIMINISH TO 5 TO 10 KT TONIGHT.
ON FRIDAY, WINDS TURN S 5 TO 10 KT IN THE MORNING, INCREASING
TO 15 TO 20 KT. GUSTS UP TO 25 KT POSSIBLE LATE. SEAS 2 TO 4 FT,
POSSIBLY BUILDING TO 3 TO 5 FT LATE. A NEW SCA MAY BE NEEDED
FOR LATE FRIDAY.
FOG WILL BE DEVELOPING ON THE WATERS TONIGHT, WITH VSBYS FROM 1
TO 3 NM, AND VSBYS MAY EVEN BE LESS THAN 1 NM FRIDAY MORNING. A
MARINE DENSE FOG ADVISORY MAY BE NEEDED IN THE MORNING. VSBYS
SHOULD IMPROVE FRIDAY AFTERNOON.
OUTLOOK...
FRIDAY NIGHT...A PERIOD OF SCA CONDITIONS POSSIBLE FRIDAY
AFTERNOON AND EVENING AS WINDS RAMP UP AND SEAS BUILD TO AROUND
5 FEET.
SATURDAY THROUGH SATURDAY NIGHT...SUB-SCA CONDITIONS SATURDAY,
THEN SCA CONDITIONS LIKELY SATURDAY NIGHT
SUNDAY THROUGH SUNDAY NIGHT...SCA CONDITIONS LIKELY WITH A
BRIEF PERIOD OF GALE FORCE WINDS POSSIBLE SUNDAY AFTERNOON.
WINDS DIMINISH TO SUB-SCA LEVELS SUNDAY NIGHT, BUT SEAS REMAIN
ELEVATED. VISIBILITY RESTRICTIONS IN SHOWERS EXPECTED.
MONDAY...SUB-SCA CONDITIONS LIKELY.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ450>452.
DISCUSSION...GUZZO/MJL/MPS
AVIATION...GUZZO/MJL/MPS
MARINE...GUZZO/MJL/MPS
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