016
FXUS61 KPHI 022357
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
757 PM EDT THU APR 2 2026
WHAT HAS CHANGED
WIDESPREAD FOG WILL DEVELOP TONIGHT WITH PATCHY DENSE FOG
LIKELY AROUND DAYBREAK FRIDAY.
MARINE DENSE FOG ADVISORY ISSUED FOR ALL ATLANTIC COASTAL
WATERS AND DELAWARE BAY.
KEY MESSAGES
1. MARINE LAYER WILL REMAIN IN PLACE ACROSS THE REGION
OVERNIGHT, THEN SCATTER OUT ON FRIDAY AFTERNOON. THIS WILL
SUPPORT WIDESPREAD FOG DEVELOPMENT OVERNIGHT AND FRIDAY MORNING,
ALONG WITH CONTINUED COLD AND DAMP CONDITIONS FOLLOWED BY
WARMER AND DRIER WEATHER. THERE IS POTENTIAL FOR DENSE FOG.
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...MARINE LAYER WILL REMAIN IN PLACE ACROSS THE
REGION OVERNIGHT, THEN SCATTER OUT ON FRIDAY AFTERNOON. THIS
WILL SUPPORT WIDESPREAD FOG DEVELOPMENT OVERNIGHT AND FRIDAY
MORNING, ALONG WITH CONTINUED COLD AND DAMP CONDITIONS FOLLOWED
BY WARMER AND DRIER WEATHER. THERE IS POTENTIAL FOR DENSE FOG.
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 INTO TONIGHT. ANOTHER WEAK BOUNDARY OUT AHEAD OF THAT
LOW WILL LIFT NORTH THROUGH THE NORTHERN HALF OF THE FORECAST
AREA, AND THIS MAY INITIATE 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 AREAS OF 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 WARM FRONT IS EXPECTED TO LIFT NORTH THROUGH THE REGION ON
SATURDAY AS LOW PRESSURE BEGINS TO SHIFT NORTHEASTWARD OUT OF
THE GREAT LAKES REGION. SCATTERED SHOWERS WILL BE POSSIBLE IN
THE VICINITY OF THE FRONT THROUGH THE DAY SATURDAY, WITH HIGHEST
CHANCES ACROSS NORTHERN PARTS OF THE AREA. THERE MAY BE ENOUGH
ELEVATED INSTABILITY TO ALLOW FOR A FEW RUMBLES OF THUNDER.
OTHERWISE, MUCH WARMER TEMPERATURES WILL SURGE INTO THE REGION,
HIGHS ON SATURDAY RISING INTO THE MID 70S TO LOW 80S OUTSIDE OF
THE POCONOS AND NEAR THE COAST, WHERE MID 60S ARE EXPECTED. LOWS
SATURDAY NIGHT LOOK TO GENERALLY BE IN THE 40S AND 50S, BUT MAY
REMAIN ABOVE 60 IN PARTS OF DELMARVA.
THERE WILL LIKELY BE A RELATIVE LULL IN SHOWER CHANCES EARLY
SUNDAY WITH THE REGION IN THE WARM SECTOR AHEAD OF A COLD FRONT
THAT WILL SWEEP ACROSS THE REGION BY SUNDAY AFTERNOON. HIGH
TEMPERATURES ON SUNDAY WILL BE HIGHLY DEPENDENT ON THE TIMING OF
THE FRONTAL PASSAGE WHICH REMAINS SOMEWHAT IN QUESTION, BUT
THERE SHOULD BE ENOUGH TIME FOR MOST OF NJ SOUTHWARD INTO
DELMARVA TO RISE INTO THE LOW-MID 70S. WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS ARE EXPECTED ALONG AND JUST AHEAD OF THE
COLD FRONT. AS OF RIGHT NOW, ANY SEVERE WEATHER THREAT LOOKS
QUITE LIMITED WITH THE PRIMARY LIMITING FACTOR BEING THE DEGREE
OF DESTABILIZATION, WITH MEAGER INSTABILITY AT BEST DEPICTED IN
MODEL GUIDANCE. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE GIVEN
RICH MOISTURE IN PLACE, AND PWATS AROUND 1.5", WHICH IS WELL
ABOVE THE 90TH PERCENTILE FOR THIS TIME OF YEAR. HOWEVER, GIVEN
THAT THIS IS EXPECTED TO BE A FAST MOVING SYSTEM, FLASH FLOODING
IS NOT CURRENTLY EXPECTED TO BE A CONCERN. TOTAL RAINFALL
AMOUNTS LOOK TO BE IN THE NEIGHBORHOOD OF 0.5", THOUGH LOCALLY
HIGHER AMOUNTS COULD OCCUR IN HEAVIER SHOWERS OR STORMS. BREEZY
CONDITIONS ARE LIKELY ON SUNDAY EVEN OUTSIDE OF ANY SHOWERS AND
STORMS WITH SOUTHWESTERLY WINDS GUSTING 25-35 MPH AHEAD OF THE
FRONT, WITH SIMILAR WESTERLY WINDS BEHIND IT.
IN THE WAKE OF THE COLD FRONT, TEMPERATURES ARE EXPECTED TO
RETURN TO NEAR OR EVEN SLIGHTLY BELOW NORMAL, WITH HIGHS MOSTLY
IN THE 50S AND LOWS IN THE 30S AND 40S THROUGH MID-WEEK. A SLOW
WARM UP MAY BEGIN THURSDAY AND BEYOND.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...CIGS LOWER TO LIFR BY 06Z. MVFR TO IFR VSBYS IN DZ/BR
FOR MOST OF THE NIGHT. VSBYS WILL DROP TO LESS THAN 1SM BEFORE
12Z. E WINDS NEAR 10 KT, BECOMING 5 KT OR LESS AFTER 09Z.
MODERATE CONFIDENCE IN TIMING OF CONDITIONS, BUT HIGH CONFIDENCE
IN PREVAILING IFR AND WORSENING CONDITIONS OVERNIGHT.
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. A FEW SHOWERS DURING THE EVENING
COULD LEAD TO BRIEF SUB-VFR CONDITIONS.
SATURDAY THROUGH SATURDAY NIGHT...SUB-VFR CONDITIONS ARE
POSSIBLE AT TIMES IN SHOWERS AND PERHAPS A FEW THUNDERSTORMS.
SUNDAY...SUB-VFR EXPECTED WITH A PERIOD OF SHOWERS AND STORMS.
GUSTY WINDS LIKELY THROUGH THE DAY SUNDAY.
SUNDAY NIGHT...CONDITIONS IMPROVE TO VFR AFTER THE EVENING
HOURS.
MONDAY THROUGH TUESDAY...PRIMARILY VFR. THERE IS A SLIGHT
CHANCE (AROUND 20%) FOR A FEW SHOWERS MONDAY NIGHT AND TUESDAY.
MARINE
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE OCEAN WATERS
FROM SANDY HOOK NJ TO GREAT EGG INLET, NJ UNTIL 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. VSBYS MAY DROP LESS THAN 1 NM. A MARINE DENSE FOG
ADVISORY WAS ISSUED FOR ALL ATLANTIC COASTAL WATERS AND DELAWARE
BAY BEGINNING TONIGHT OR EARLY FRIDAY AND INTO THE AFTERNOON.
VSBYS SHOULD IMPROVE FRIDAY AFTERNOON.
OUTLOOK...
FRIDAY NIGHT...SCA CONDITIONS LIKELY IN THE EVENING HOURS.
SOUTHWEST WINDS 10-15 KT WITH GUSTS UP TO 25 KT, DECREASING TO
AROUND 10 KT WITH GUSTS UP TO 20 KT LATE. SEAS 3-6 FEET
DECREASING TO 2-4 FEET.
SATURDAY...NO MARINE HEADLINES CURRENTLY ANTICIPATED WITH WINDS
UNDER 25 KT AND SEAS UNDER 5 FEET.
SATURDAY NIGHT THROUGH SUNDAY...SCA CONDITIONS LIKELY WITH
GALES POSSIBLE. SOUTHERLY WINDS SATURDAY NIGHT WILL INCREASE TO
15-25 KT WITH GUSTS TO 30-35 KT. WINDS WILL BECOME SOUTHWESTERLY
ON SUNDAY. SEAS 4-8 FEET.
SUNDAY NIGHT THROUGH MONDAY...LINGERING SCA CONDITIONS LIKELY.
WINDS QUICKLY SUBSIDE TO BELOW 25 KT. SEAS REMAIN ELEVATED NEAR
5 FEET THROUGH MONDAY MORNING BEFORE DECREASING BELOW 5 FEET BY
MONDAY AFTERNOON.
MONDAY NIGHT THROUGH TUESDAY...NO MARINE HEADLINES CURRENTLY
ANTICIPATED WITH WINDS UNDER 25 KT AND SEAS UNDER 5 FEET.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 2 PM EDT FRIDAY FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ450>452.
DENSE FOG ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR ANZ450.
DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT FRIDAY
FOR ANZ451-452.
DENSE FOG ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ453-454.
DENSE FOG ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ455.
DISCUSSION...COOPER/MPS/STAARMANN
AVIATION...COOPER/MPS/STAARMANN
MARINE...COOPER/MPS/STAARMANN
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