809
FXUS61 KPHI 071506
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1006 AM EST SAT MAR 7 2026
WHAT HAS CHANGED
DENSE FOG ADVISORIES HAVE BEEN EXTENDED UNTIL 12 PM. MARINE
DENSE FOG ADVISORIES HAVE BEEN EXTENDED UNTIL 3 PM.
KEY MESSAGES
1. PATCHY DENSE FOG THROUGH THIS MORNING IS FOLLOWED BY A WARM
FRONT AND COLD FRONT LATE TODAY INTO TONIGHT.
2. WARMER AIR GRADUALLY OVERSPREADS THE REGION LATER THIS WEEKEND
INTO EARLY NEXT WEEK, WITH A COUPLE CHANCES FOR SHOWERS AND FOG.
DISCUSSION
KEY MESSAGE 1...PATCHY DENSE FOG THROUGH THIS MORNING IS FOLLOWED
BY A WARM FRONT AND COLD FRONT LATE TODAY INTO TONIGHT.
CANADIAN HIGH PRESSURE HAS CONTINUED TO USHER IN COOLER AIR FROM THE
NORTHEAST WHICH HAS ACTED LIKE A BACKDOOR COLD FRONT FOR THE AREA.
OUR HIGH PRESSURE SYSTEM STARTS TO MOVE OFFSHORE THROUGH THE DAY
TODAY WHICH WILL OPEN UP THE OPPORTUNITY FOR A WARM FRONT AND
COLD FRONT TO MOVE THROUGH.
WE SEE WARM AIR ADVECTION IN THE LOW-LEVELS TODAY. THIS WILL BE
FOLLOWED BY THE SURFACE TEMPERATURES LATER TODAY AND INTO TONIGHT AS
A WARM FRONT MOVES THROUGH. THIS WARM AIR ADVECTION IN THE LOW-
LEVELS HAS A STEEP LOW-LEVEL INVERSION WHICH HAS MOISTURE
TRAPPED BENEATH IT. THIS MOISTURE ALONG WITH A SATURATED GROUND
AND RELATIVELY LIGHT WINDS HAVE RESULTED IN PLENTY OF STRATUS
BUT ALSO DENSE FOG IN SPOTS. A DENSE FOG ADVISORY REMAINS IN
EFFECT FOR MONROE COUNTY AND THE COASTAL ZONES OF NEW JERSEY AND
DELAWARE UNTIL 12 PM TODAY. THE REDUCED VISIBILITY SHOULD
IMPROVE SOME THROUGH THE DAY TODAY BUT THE CLOUDS STICK WITH US.
TODAY WILL BE ANOTHER COOLER DAY WITH HIGHS FOR MOST IN THE MID 40S
TO LOW 50S. PARTS OF DELMARVA SEE HIGHS IN THE UPPER 50S TO LOW 60S
AS THE WARM AIR ADVECTION MOVES SOUTH TO NORTH. TEMPERATURES WILL
ACTUALLY WARM OVERNIGHT AS WE CONTINUE TO SEE THAT WARM AIR FILTER
IN WITH A MORE SOUTHWEST WIND, SO OUR LOW TEMPERATURES HAPPEN EARLY.
THIS INCREASE IN TEMPERATURES OVERNIGHT IS HELPED BY THE WARM FRONT
MOVING NORTHWARD THROUGH THE AREA. A COLD FRONT FOLLOWS THIS WARM
FRONT TONIGHT INTO TOMORROW MORNING. AHEAD OF THIS COLD FRONT IS A
LINE OF SHOWERS AND POTENTIALLY EMBEDDED THUNDERSTORMS THAT WILL
WEAKEN AS THEY PASS THROUGH OUR AREA FROM WEST TO EAST LATE THIS
EVENING INTO TOMORROW MORNING.
KEY MESSAGE 2...WARMER AIR GRADUALLY OVERSPREADS THE REGION LATER
THIS WEEKEND INTO EARLY NEXT WEEK, WITH A COUPLE CHANCES FOR SHOWERS
AND FOG.
WE BECOME MORE EMBEDDED WITHIN THE WARM SECTOR BY EARLY NEXT
WEEK WITH SURFACE HIGH PRESSURE ANCHORED IN THE WESTERN ATLANTIC
AND A SOUTH TO SOUTHWEST FLOW. THIS SHOULD RESULT IN A MUCH
WARMER AIR MASS SURGING INTO THE REGION. HIGHS FOR SUNDAY AND
MONDAY ARE FORECAST TO BE IN THE 60S FOR MUCH OF THE AREA, THEN
INTO THE LOW TO SOME MID 70S FOR TUESDAY AND WEDNESDAY FOR MANY
AREAS. THE FLOW MAY BE LIGHT ENOUGH WHICH WOULD SUPPORT SEA
BREEZE CIRCULATIONS TO OCCUR DAILY, RESULTING IN SIGNIFICANT
COOLING ALONG THE COAST WHERE MANY COASTAL AREAS WILL BE STUCK
IN THE 50S.
THE MUCH MILDER AIRMASS AND HIGHER DEW POINTS NOTED ABOVE ADJACENT
TO THE COLD OCEAN EARLY NEXT WEEK WILL CREATE OPPORTUNITIES FOR
FOG, PERHAPS DENSE FOG. THESE CONDITIONS WILL BE MORE ENHANCED
CLOSER TO THE COAST AND AROUND DELAWARE BAY.
SHOWER AND THUNDERSTORM CHANCES RETURN ONCE AGAIN LATE IN THE DAY ON
WEDNESDAY INTO THURSDAY. GUIDANCE VARIES ON TIMING WHILE
BECOMING OVERALL SLOWED A LITTLE, BUT BOTH DETERMINISTIC AND
ENSEMBLE GUIDANCE SHOW SIGNALS THAT A RATHER STRONG COLD FRONT
THAT WILL TRACK THROUGH THE AREA DURING THIS TIME PERIOD.
FOLLOWING THE FRONTAL PASSAGE, THE WARMTH WILL CEASE AND WE'LL
SEE THE RETURN OF MORE SEASONABLE WEATHER TOWARDS THE END OF
NEXT WEEK. DEPENDING ON HOW QUICKLY EVERYTHING EVOLVES AND
PROGRESSES, SOME SHOWER CHANCES MAY LINGER INTO LATE WEEK, BUT
OVERALL SHOULD COME TO AN END IN WAKE OF FRONTAL PASSAGE.
AVIATION /15Z SATURDAY THROUGH WEDNESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...IFR/LIFR CONDITIONS DUE TO LOW CLOUDS AND FOG.
VISIBILITY RESTRICTIONS IMPROVE AFTER 16-18Z. LOW CEILINGS
PERSIST THROUGH THE DAY AT ALL TERMINALS. WINDS BECOME MORE
SOUTHERLY THROUGH THE MORNING. HIGH CONFIDENCE IN PREVAILING
IFR/LIFR DUE TO CEILINGS BUT LOW CONFIDENCE ON EXACT TIMING OF
VISIBILITY IMPROVEMENTS.
TONIGHT...IFR/LIFR WITH LOW CEILINGS. RAIN SHOWERS MOVE IN FROM
WEST TO EAST BETWEEN 00-02Z FOR THE LEHIGH VALLEY TERMINALS AND
I-95 TERMINALS LEADING TO VISIBILITY RESTRICTIONS AT TIMES. DUE
TO THE LINE OF SHOWERS WEAKENING, MENTION OF -SHRA WAS NOT
INCLUDED FOR KMIV/KACY. LLWS ALSO LOOKS TO DEVELOP AROUND 00Z
OUT OF THE SOUTHWEST AT AROUND 45 KNOTS AT ALL TERMINALS. AFTER
09Z, THE LLWS LOOKS TO END AND SHOWER COVERAGE LESSENS. CEILINGS
CONTINUE TO REMAIN AT IFR/LIFR. MODERATE CONFIDENCE.
OUTLOOK...
SUNDAY...SUB-VFR CONDITIONS LIKELY WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS EARLY. CONDITIONS MAY IMPROVE TO VFR BY
AFTERNOON.
SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR PREVAILS. LOCALIZED
SUB-VFR CONDITIONS POSSIBLE AT TIMES WITH FOG.
WEDNESDAY...SHOWER CHANCES INCREASE WITH MORE POTENTIAL FOR
SUB-VFR.
MARINE
MARINE CONDITIONS ARE EXPECTED TO STAY BELOW SCA CRITERIA
THROUGH TODAY. MARINE DENSE FOG HAS DEVELOPED LEADING TO A
MARINE DENSE FOG ADVISORY BEING ISSUED THROUGH 3 PM THIS
AFTERNOON.
A SMALL CRAFT ADVISORY GOES INTO EFFECT THIS EVENING THROUGH
TONIGHT FOR ALL THE ATLANTIC COASTAL WATERS FOR WIND GUSTS UP
TO 25 KNOTS AND SEAS INCREASING TO 5-7 FEET.
OUTLOOK...
SUNDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL ATLANTIC
COASTAL WATERS DUE MAINLY TO SEAS OF 5-7 FEET, THOUGH WINDS MAY
ALSO GUST UP TO 25 KTS. A CHANCE FOR RAIN SHOWERS.
SUNDAY NIGHT THROUGH TUESDAY NIGHT...NO MARINE HEADLINES EXPECTED.
WINDS GENERALLY LESS THAN 15 KT AND SEAS AROUND 2-4 FEET.
WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS LIKELY. WIND GUSTS UP TO
30 KT AND SEAS BUILDING UP TO 7 FEET. SHOWERS POSSIBLE LATE.
PHI WATCHES/WARNINGS/ADVISORIES
PA...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR PAZ055.
NJ...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR NJZ013-014-020-
022>027.
DE...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR DEZ003-004.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ430-
431-450>455.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 PM EST SUNDAY
FOR ANZ450>455.
DISCUSSION...DESILVA/GUZZO/RCM
AVIATION...DESILVA/GUZZO/RCM
MARINE...DESILVA/GUZZO/RCM
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