755
FXUS61 KPHI 271344
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
944 AM EDT SUN APR 27 2025
SYNOPSIS
AS LOW PRESSURE GRADUALLY DEPARTS NORTHERN NEW ENGLAND LATER TODAY,
HIGH PRESSURE GRADUALLY STARTS TO APPROACH OUR AREA FROM THE WEST.
THE HIGH THEN SHIFTS TO OUR SOUTH AND EAST MONDAY INTO MONDAY NIGHT.
A WARM FRONT ARRIVES BY LATER TUESDAY, FOLLOWED BY A COLD FRONT LATE
TUESDAY NIGHT AND WEDNESDAY MORNING. HIGH PRESSURE BRIEFLY ARRIVES
FOR THURSDAY, THEN LOW PRESSURE TRACKS ACROSS THE EASTERN GREAT
LAKES FRIDAY WITH A COLD FRONT MOVING THROUGH LATE FRIDAY INTO
SATURDAY.
NEAR TERM /THROUGH TONIGHT/
NO SIGNIFICANT CHANGES WILL BE MADE TO THE DATABASE AS THE
FORECAST IS RUNNING ON TRACK.
COLD AND DRY AIR ADVECTION CONTINUES. DEWPOINTS ACROSS THE
REGION HAVE DROPPED INTO THE 30S, WHICH IS A FAR CRY FROM THE 60
PLUS DEWPOINTS AHEAD OF THE FRONT ON SATURDAY.
THE MAIN STORY THROUGH THE DAY TODAY WILL BE THE WIND. WE WILL
CONTINUE TO HAVE A TIGHT PRESSURE GRADIENT ACROSS THE REGION AS
THE HIGH BUILDS CLOSER. IN GENERAL, IT LOOKS LIKE PEAK WIND
GUSTS AROUND 35 MPH WILL BE POSSIBLE THROUGH THE DAY, THOUGH IN
THE HIGHER TERRAIN OF THE SOUTHERN POCONOS, MODEL SOUNDINGS
DEPICT WIND SPEEDS UP TO 50 MPH AT THE TOP OF THE MIXED LAYER.
ALTHOUGH IT WON'T EFFICIENTLY MIX DOWN, PEAK WIND GUSTS OF 45 TO
50 MPH ARE EXPECTED IN THE HIGHER TERRAIN OF CARBON AND MONROE
COUNTIES. THEREFORE, A WIND ADVISORY HAS BEEN ISSUED FOR THOSE
COUNTIES THROUGH 5 PM.
STRATOCUMULUS, ESPECIALLY NORTH AND WEST OF THE FALL LINE, WILL
MEAN MOSTLY CLOUDY CONDITIONS FOR PORTIONS OF THE REGION
THROUGH AT LEAST EARLY AFTERNOON.
PRESSURE GRADIENT STARTS TO RELAX LATE THIS AFTERNOON WHICH
WILL RESULT IN DECREASING WINDS AND THE CLOUDS ERODING. STILL
COULD HAVE WINDS AROUND 10 TO 15 MPH THROUGH THE NIGHT, SO NOT
THE MOST EFFICIENT RADIATIONAL COOLING CONDITIONS, BUT
SUFFICIENT ENOUGH FOR TEMPERATURES TO DROP INTO THE 40S FOR MOST
OF THE AREA.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
SOME MID LEVEL RIDGING ARRIVES MONDAY FROM THE WEST AND THIS WILL
ALLOW SURFACE HIGH PRESSURE TO SLIDE OVER OUR AREA, ALTHOUGH THE
CENTER OF THE HIGH LOOKS TO BECOME MORE FOCUSED TO OUR SOUTH WITH
TIME. THIS WILL RESULT IN LESS WIND AND WITH HEIGHTS ON THE RISE IT
WILL BE A WARMER AFTERNOON. HIGH TEMPERATURES LOOK TO BE SEVERAL
DEGREES HIGHER THAN SUNDAY. NORTHWEST WINDS WILL BE LESS AND AS THE
FLOW TURNS EVEN LIGHTER A SEA/BAY BREEZE SHOULD DEVELOP DURING THE
COURSE OF THE AFTERNOON, RESULTING IN COOLING ALONG THE COAST.
TEMPERATURES MONDAY NIGHT LOOK TO DROP BACK INTO THE MID/UPPER 40S
TO SOME LOW 50S.
AS WE GO THROUGH TUESDAY, A WARM FRONT LOOKS TO LIFT ACROSS OUR AREA
BY LATER IN THE DAY. AN UPPER-LEVEL TROUGH SHIFTS EAST INTO THE
NORTHEAST FROM THE GREAT LAKES AND ADJACENT CANADA, WITH A COLD
FRONT CROSSING PARTS OF OUR AREA LATER AT NIGHT. THIS MAY END UP
BEING A QUICK MOVING SYSTEM WITH NOT MUCH TIME FOR DEEPER MOISTURE
RETURN AND THEREFORE SHOWERS MAY BE LIMITED. THERE STILL LOOKS TO BE
SOME CHANCE FOR SHOWERS TUESDAY NIGHT AS THE COLD FRONT ITSELF
ARRIVES, THEREFORE HELD ONTO SOME SLIGHT CHANCE TO LOW CHANCE POPS
(20-30 PERCENT) MOSTLY NORTH AND WEST OF I-95. THE COLD FRONT
CONTINUES TO LOOK FASTER WITH IT CROSSING AT LEAST PARTS OF OUR
AREA TUESDAY NIGHT. A SOUTH TO SOUTHWEST BREEZE SHOULD INCREASE SOME
DURING TUESDAY AS THE PRESSURE GRADIENT TIGHTENS SOME AHEAD OF THE
ADVANCING COLD FRONT. TEMPERATURES TUESDAY SHOULD TOP OUT AROUND 80
DEGREES FOR MUCH OF THE AREA, AND DEW POINTS ARE FORECAST TO RISE
THROUGH THE 40S INTO THE LOWER 50S. TEMPERATURES ARE FORECAST TO BE
MILD TUESDAY NIGHT AS WE AWAIT THE ARRIVAL OF THE COLD FRONT, AND
THE AIR MASS BEHIND IT DOES NOT LOOK AT THAT COLDER.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
SUMMARY...MILD TO WARM TEMPERATURES WITH SOME CHANCES FOR SHOWERS.
SYNOPTIC OVERVIEW...AN UPPER-LEVEL TROUGH SLIDES ACROSS SOUTHERN
CANADA AND THE NORTHEAST INTO WEDNESDAY. ANOTHER BRIEF MID/UPPER
RIDGE BUILDS OVERHEAD ON THURSDAY FOLLOWED QUICKLY BY ANOTHER UPPER-
LEVEL TROUGH FRIDAY INTO SATURDAY. AT THE SURFACE, A COLD FRONT
SHIFTS SOUTH AND EAST OF OUR AREA WEDNESDAY AND THE HIGH PRESSURE
SLIDES BY TO OUR NORTH ON THURSDAY. LOW PRESSURE TRACKS NEAR THE
EASTERN GREAT LAKES FRIDAY INTO SATURDAY, PULLING A COLD FRONT
ACROSS OUR AREA.
FOR WEDNESDAY...A COLD FRONT SETTLES TO OUR EAST AND SOUTH AND THEN
STALLS AT NIGHT. THE MOISTURE AND FORCING LOOKS TO BE LACKING SO IT
MAY END UP MOVING THROUGH DRY. IN WAKE OF THE FRONT, A DRY WEST-
NORTHWEST BREEZE INCREASES SOME THROUGH THE AFTERNOON. HIGH
TEMPERATURES ARE FORECAST TO BE IN THE MID/UPPER 70S TO SOME LOW
80S, ALTHOUGH 60S IN THE HIGHER ELEVATIONS. THE FRONT WILL START TO
LIFT BACK NORTHWARD AT NIGHT AS A WARM FRONT AND SOME SHOWERS COULD
DEVELOP IN ADVANCE OF THAT, HOWEVER CHANCES ARE LOW AT THIS POINT.
FOR THURSDAY THROUGH SATURDAY...SURFACE HIGH PRESSURE IS FORECAST TO
SLIDE BY TO OUR NORTH ON THURSDAY. AS THE FLOW VEERS FROM SOUTHEAST
TO SOUTHWEST, WARM AIR ADVECTION GETS UNDERWAY ESPECIALLY AS A WARM
FRONT ARRIVES. THE INCREASING ISENTROPIC LIFT IN ADVANCE OF AN
APPROACHING UPPER-LEVEL TROUGH MAY RESULT IN SOME SHOWERS LATER
THURSDAY. AT LEAST SOME ELEVATED INSTABILITY CANNOT BE RULED OUT
THURSDAY NIGHT. THE AFOREMENTIONED UPPER-LEVEL TROUGH DRIVES SURFACE
LOW PRESSURE ACROSS THE EASTERN GREAT LAKES AND VICINITY FRIDAY, AND
THIS PULLS A COLD FRONT ACROSS OUR AREA FRIDAY AFTERNOON AND NIGHT.
INCREASING FORCING FOR ASCENT TIED TO THIS INCOMING UPPER-LEVEL
TROUGH AND COLD FRONT SHOULD RESULT IN AN INCREASE IN SHOWERS FOR A
TIME. SOME THUNDER IS POSSIBLE GIVEN ENOUGH INSTABILITY AS OUR
REGION IS FORECAST TO BE IN THE WARM SECTOR ALONG WITH MORE HUMID
CONDITIONS. MILD TO WARM TEMPERATURES WILL COOL SOME SATURDAY IN THE
WAKE OF A SECONDARY COLD FRONT.
AVIATION /14Z SUNDAY THROUGH THURSDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR EXPECTED. SCATTERED TO BROKEN CLOUDS AROUND 5K FT
AGL REMAIN POSSIBLE THROUGH MUCH OF THE DAY. NORTHWEST WIND 15
TO 20 KTS WITH 30 TO 35 KT GUSTS. HIGH CONFIDENCE.
TONIGHT...VFR WITH CLEARING SKIES. NORTHWEST WIND AROUND 10 KT.
HIGH CONFIDENCE.
OUTLOOK...
MONDAY...VFR. AN AFTERNOON SEA BREEZE MAY AFFECT KACY AND KMIV,
AND A BAY BREEZE MAY AFFECT KILG.
TUESDAY...VFR, HOWEVER A BRIEF PERIOD OF SUB-VFR CONDITIONS ARE
POSSIBLE AT NIGHT.
WEDNESDAY...VFR OVERALL.
THURSDAY...SOME TIMES OF SUB-VFR CONDITIONS POSSIBLE ALONG WITH A
RISK OF SHOWERS AND A FEW THUNDERSTORMS.
MARINE
SMALL CRAFT ADVISORY CONDITIONS CONTINUE ON THE AREA WATERS
THROUGH THE DAY TODAY. WINDS SHOULD BEGIN TO DIMINISH MID TO
LATE AFTERNOON. THERE IS A CHANCE THAT 25 KT WIND GUSTS WILL
LINGER FOR A FEW MORE HOURS INTO THE EVENING FOR THE COASTAL
WATERS ADJACENT TO THE CENTRAL AND NORTHERN NJ COAST, BUT
CONFIDENCE IS TOO LOW TO EXTEND THE SCA AT THIS TIME.
OTHERWISE, ONCE WINDS SUBSIDE BELOW 25 KT, WINDS AND SEAS SHOULD
STAY BELOW SCA CRITERIA FOR THE REST OF THE NIGHT.
OUTLOOK...
MONDAY...THE CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT
ADVISORY CRITERIA.
TUESDAY...SMALL CRAFT ADVISORY CONDITIONS PROBABLE, ESPECIALLY LATE
AFTERNOON AND EVENING.
WEDNESDAY AND THURSDAY...THE CONDITIONS ARE ANTICIPATED TO BE BELOW
SMALL CRAFT ADVISORY CRITERIA.
FIRE WEATHER
FOR TODAY, NORTHWEST WINDS 15-25 MPH WITH GUSTS UP TO 40 MPH.
IN ADDITION, RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP TO
25-35 PERCENT NEAR AND ESPECIALLY SOUTH OF I-78 (35-45 PERCENT
NORTH OF I-78). HOW QUICKLY THE FUELS DRY OUT FROM THE SHOWERS
YESTERDAY WILL DETERMINE ANY RAPID FIRE SPREAD RISK.
PHI WATCHES/WARNINGS/ADVISORIES
PA...WIND ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR PAZ054-055.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ430-
431-450>455.
SYNOPSIS...GORSE
NEAR TERM...JOHNSON/MPS
SHORT TERM...GORSE
LONG TERM...GORSE
AVIATION...GORSE/JOHNSON
MARINE...GORSE/JOHNSON
FIRE WEATHER...
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