897
FXUS61 KPHI 121148
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
748 AM EDT TUE MAY 12 2026
WHAT HAS CHANGED
THE FROST ADVISORY IS NO LONGER IN EFFECT.
KEY MESSAGES
1. A DRIER AIRMASS SPREADS INTO THE REGION TODAY.
2. SHOWERS (A FEW THUNDERSTORMS POSSIBLE) WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT, THEN SOME SHOWERS CONTINUING INTO THURSDAY MORNING.
3. BECOMING VERY WARM TO POTENTIALLY HOT THIS WEEKEND THROUGH EARLY
NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...A DRIER AIRMASS SPREADS INTO THE REGION TODAY.
TEMPERATURES IN THE SOUTHERN POCONOS CONTINUE TO RISE INTO THE
LOWER 40S. THEREFORE, THE FROST ADVISORY IS NO LONGER IN EFFECT.
HIGH PRESSURE OVER THE AREA RESULTS IN SUNNY SKIES WITH MILD
TEMPERATURES FOR THIS TIME OF THE YEAR. HIGHS WILL TOP OFF IN
THE UPPER 60S TO AROUND 70.
KEY MESSAGE 2...SHOWERS (A FEW THUNDERSTORMS POSSIBLE)
WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT, THEN SOME SHOWERS
CONTINUING INTO THURSDAY MORNING.
AN UPPER-LEVEL TROUGH MOVES INTO THE EASTERN U.S. WEDNESDAY INTO
THURSDAY BEFORE LIFTING OUT FRIDAY INTO SATURDAY. THIS TROUGH LOOKS
TO BECOME A CLOSED LOW OVER THE MID-ATLANTIC AND NORTHEAST BY
THURSDAY. THE DETAILS WILL DEPEND ON THE TIMING OF THE CLOSED LOW
AND ITS TRACK, HOWEVER AS IT ARRIVES SHOWERS WILL BE ON THE INCREASE
WEDNESDAY AFTERNOON AND ESPECIALLY WEDNESDAY NIGHT BEFORE TAPERING
OFF INTO THURSDAY AS A COLD FRONT SHIFTS OFFSHORE.
THE LOW-LEVEL WARM AIR ADVECTION WILL INCREASE AHEAD OF THE TROUGH
DURING WEDNESDAY AS WILL THE LOW TO MID LEVEL FLOW. THIS WILL RESULT
IN AN INCREASE IN FORCING FOR ASCENT, AND SOME INSTABILITY SHOULD
DEVELOP AHEAD OF THE MAIN FORCING. A WARM FRONT SHOULD ALSO LIFT
ACROSS OUR AREA WEDNESDAY WITH SOME ASCENT ASSOCIATED WITH IT. AS A
RESULT, SHOWERS INCREASE WEDNESDAY AFTERNOON FROM WEST TO EAST WITH
FORCING PEAKING WEDNESDAY NIGHT AS THE COLD FRONT ARRIVES. GUIDANCE
CONTINUES TO SHOW SOME INSTABILITY WHICH COULD BE ENOUGH TO SUPPORT
A FEW THUNDERSTORMS. THE INTENSITY OF ANY THUNDERSTORMS HOWEVER WILL
DEPEND ON THE MAGNITUDE OF THE INSTABILITY AND SHEAR. GIVEN THE
LATER ARRIVAL TIME OF THE SHOWERS, INSTABILITY LOOKS TO BE RATHER
WEAK WITH AN ISOLATED SEVERE THUNDERSTORM RISK WELL TO OUR WEST
WEDNESDAY AFTERNOON.
THE MAIN FORCING SHIFTS TO OUR EAST AND NORTHEAST THURSDAY WITH THE
BULK OF THE SHOWERS ENDING. HOWEVER, THE PRESENCE OF THE CLOSED LOW
ESPECIALLY OVERHEAD WITH THE CORE OF THE COLD AIR ALOFT COULD RESULT
IN ADDITIONAL SHOWER DEVELOPMENT ON THURSDAY BEFORE THE SYSTEM
DEPARTS OUR REGION. RAINFALL TOTALS LOOK TO BE ON THE LIGHTER SIDE
(0.20-0.50 INCHES), ALTHOUGH LOCALLY HIGHER AMOUNTS ARE POSSIBLE IF
MORE ORGANIZED SHOWERS/THUNDER OCCUR.
KEY MESSAGE 3...BECOMING VERY WARM TO POTENTIALLY HOT THIS WEEKEND
THROUGH EARLY NEXT WEEK.
AS THE CLOSED LOW CONTINUES TO DEPART GOING INTO THE WEEKEND, A RIDGE
STARTS TO BUILD ACROSS THE EAST THIS WEEKEND AND INTO EARLY NEXT
WEEK. THIS ALONG WITH HIGH PRESSURE CENTERED OFFSHORE WILL RESULT IN
SOUTHERLY FLOW ADVECTING IN A MUCH WARMER AIR MASS ACROSS OUR AREA.
AS A RESULT, HIGH TEMPERATURES GET INTO THE 70S TO LOW 80S SATURDAY
WITH WIDESPREAD 80S ON SUNDAY. GIVEN A SOUTHERLY WIND COMPONENT
THOUGH, IT SHOULD BE COOLER ALONG THE COAST. THE HEAT LOOKS TO BUILD
INTO EARLY NEXT WEEK WITH EVEN HOT CONDITIONS POSSIBLE. HIGHS MONDAY
ARE FORECAST TO BE IN THE 80S WITH EVEN SOME AREAS REACHING 90
DEGREES (AGAIN COOLER ALONG THE COAST). GIVEN THE PRESENCE OF THE
RIDGE ALOFT, NO PRECIPITATION IS CURRENTLY ANTICIPATED. HOWEVER NEAR
THE EDGE OF THE RIDGE/SURFACE HIGH, THERE IS A SLIGHT CHANCE (20
PERCENT) FOR CONVECTION NEAR THE SOUTHERN POCONOS MONDAY AFTERNOON
AND EVENING.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS...
TODAY...VFR. SOME HIGH CLOUDS LATER TODAY. LIGHT AND VARIABLE
TO CALM WINDS BECOMING NORTH-NORTHWEST 5-10 KNOTS THIS MORNING,
THEN BECOMING WEST TO SOUTHWEST AND SOUTH THIS AFTERNOON. HIGH
CONFIDENCE.
TONIGHT...VFR WITH INCREASING HIGH CLOUDS. LIGHT SOUTH WINDS.
HIGH CONFIDENCE.
OUTLOOK...
WEDNESDAY...VFR CONDITIONS DURING MOST OF THE DAY, THEN CONDITIONS
LOWER TO MVFR OR IFR MAINLY AT NIGHT AS SHOWERS ARRIVE FROM WEST TO
EAST. A FEW THUNDERSTORMS POSSIBLE LATE IN THE AFTERNOON AND
EVENING. SOUTHERLY WIND GUSTS UP TO 25 KNOTS DURING THE AFTERNOON.
THURSDAY...TIMES OF SUB-VFR CONDITIONS WITH SOME SHOWERS POSSIBLE,
OTHERWISE VFR. WEST-NORTHWEST WIND GUSTS TO 20 KNOTS POSSIBLE.
FRIDAY...MOSTLY VFR. AN ISOLATED SHOWER POSSIBLE.
MARINE
HIGH PRESSURE ACROSS PENNSYLVANIA AND NEW JERSEY THIS MORNING WILL
MOVE OFFSHORE THIS AFTERNOON. FAIR WEATHER IS EXPECTED TODAY AND
TONIGHT. WINDS WILL BEGIN THE DAY MOSTLY NORTH OR NORTHWEST ON THE
WATERS AND WILL REMAIN LIGHT AS THE HIGH MOVES OVERHEAD. LATER
TODAY WINDS WILL TURN SOUTHWEST OR SOUTH AND INCREASE TO 5 TO 10
KNOTS. TONIGHT, WINDS SPEEDS WILL FURTHER INCREASE TO 10 TO 15
KNOTS WITH GUSTS AROUND 20 KNOTS. CONDITIONS WILL REMAIN BELOW
SCA LEVELS BUT SEAS WILL INCREASE CLOSE TO 4FT BY WEDNESDAY
MORNING.
OUTLOOK...
WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS ARE PROBABLE.
THURSDAY THROUGH SATURDAY...THE CONDITIONS ARE ANTICIPATED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...GORSE/MPS/OHARA
AVIATION...GORSE/OHARA
MARINE...GORSE/OHARA
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