409
FXUS61 KPHI 110515
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
115 AM EDT MON MAY 11 2026
WHAT HAS CHANGED
AVIATION SECTION UPDATED WITH 06Z TAF ISSUANCE.
THE COLD FRONT CONTINUES TO SLOWLY PROGRESS THROUGH THE REGION.
KEY MESSAGES
1. A COLD FRONT WILL BRING A CHANCE FOR SHOWERS TO THE AREA
THIS EVENING THROUGH TONIGHT.
2. ADDITIONAL OPPORTUNITIES FOR RAINFALL THIS WEEK.
DISCUSSION
KEY MESSAGE 1...A COLD FRONT WILL BRING A CHANCE FOR SHOWERS TO
THE AREA THIS EVENING THROUGH TONIGHT.
AS OF THIS EVENING, THE SURFACE COLD FRONT IS SLOWLY
PROGRESSING THROUGH THE REGION AND SHOULD BE CROSSING OFF SHORE
BY LATE THIS EVENING. IN THE MID AND UPPER LEVELS, A LARGE SCALE
TROUGH CENTERED OVER PORTIONS OF ONTARIO AND QUEBEC WILL SHIFT
SLOWLY EASTWARD THROUGH TONIGHT, WITH THE REGION EMBEDDED IN
ENHANCED (45-55 KT) SOUTHWESTERLY FLOW ALOFT DOWNSTREAM OF THE
TROUGH AXIS.
WITH THE FRONT CONTINUING TO PROGRESS EASTWARD, SHOWERS ARE NOW
MAINLY CONCENTRATED FROM I-95 EASTWARD. THERE REMAINS A FEW
EMBEDDED POCKETS OF CONVECTION WITH ISOLATED THUNDERSTORMS.
THESE SHOWERS WILL CONTINUE AS THE FRONT PASSES BUT THE
THUNDERSTORM ACTIVITY WILL DIMINISH OVER THE NEXT COUPLE OF
HOURS AS INSTABILITY WANES. CAN'T COMPLETELY RULE OUT GUSTY
WINDS IF SOMETHING MORE ORGANIZED DEVELOPS BUT WITH LOW-LEVEL
LAPSE RATES DECREASING AS WE PASS SUNSET, THE THREAT FOR
ANYTHING STRONG TO SEVERE IS RAPIDLY DIMINISHING.
AFTER THE COLD FRONT PASSES, THE BROAD REGION OF ASCENT FROM THE
TROUGH WILL ALLOW FOR CONTINUED SCATTERED SHOWER DEVELOPMENT,
PRIMARILY ALONG AND SOUTHEAST OF I-95, THROUGH THE OVERNIGHT HOURS.
QPF FROM THIS EVENT LOOKS TO BE LOW, GENERALLY AROUND A TENTH OF AN
INCH OR LESS. LOWS WILL BE IN THE MID 40S TO LOW 50S.
KEY MESSAGE 2...ADDITIONAL OPPORTUNITIES FOR RAINFALL THIS WEEK.
IN THE UPPER-LEVELS THIS WEEK, THERE WILL BE TROUGHING IN PLACE
ACROSS THE REGION FOR A MAJORITY OF THIS WEEK. ONE TROUGH MOVES OUT
INTO TUESDAY WITH ANOTHER UPPER-LEVEL TROUGH MOVING IN WEDNESDAY
THROUGH FRIDAY NIGHT. THIS SECOND TROUGH BECOMES MORE AMPLIFIED AND
MAY TRY TO CLOSE OFF ON FRIDAY. RECENT GUIDANCE HAS TRENDED AWAY
FROM THE TROUGH FULLY CLOSING OFF INTO AN UPPER LOW NEAR THE MID-
ATLANTIC REGION, BUT SOME DO STILL SHOW THE CLOSED LOW FORMING JUST
OFF TO OUR NORTHEAST. REGARDLESS, WITH ALL OF THIS SAID, THERE WILL
BE MORE OPPORTUNITIES FOR UNSETTLED WEATHER THIS WEEK.
OUR FIRST TROUGH MOVES OUT MONDAY NIGHT INTO TUESDAY WITH A SURFACE
HIGH PRESSURE SYSTEM BUILDING IN. MONDAY NIGHT IS A CHILLER NIGHT AS
WINDS AND CLOUD COVER DECREASE WHICH ALLOWS FOR RADIATIONAL COOLING.
THERE IS SOME FROST POTENTIAL IN THE POCONOS MONDAY NIGHT INTO
TUESDAY MORNING.
ONCE THE HIGH PRESSURE SYSTEM EXITS ON TUESDAY NIGHT AND ANOTHER
UPPER-LEVEL TROUGH MOVES INTO THE REGION WEDNESDAY, WE SEE MORE
ACTIVE WEATHER. AT THE SURFACE, A LOW PRESSURE SYSTEM MOVES INTO THE
NORTHEAST FROM THE GREAT LAKES REGION WEDNESDAY INTO THURSDAY. THIS
LOW PRESSURE SYSTEM DRAGS A WARM FRONT THROUGH THE AREA ON WEDNESDAY
WHICH IS FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT INTO THURSDAY.
RAIN SHOWERS DEVELOP LATE TUESDAY NIGHT INTO WEDNESDAY MORNING WITH
COVERAGE INCREASING ACROSS THE AREA DURING THE DAY WEDNESDAY. DURING
WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT, THERE IS THE
POTENTIAL FOR SOME ISOLATED THUNDERSTORMS. THE EXTENT OF
DESTABILIZATION IS A BIT MORE UNCERTAIN, BUT GUIDANCE DOES SHOW SOME
INSTABILITY PRESENT TO SUPPORT ISOLATED THUNDERSTORMS. SHOWERS
LINGER INTO THURSDAY AS OUR LOW PRESSURE SYSTEM DEPARTS.
BEYOND THURSDAY, THERE IS SOME UNCERTAINTY FOR FRIDAY WHICH
CORRESPONDS TO IF THE UPPER-LEVEL TROUGH IS MORE PROGRESSIVE OR
CLOSES OFF INTO A CLOSED LOW NEAR THE AREA. RECENT TRENDS HAVE BEEN
A BIT DRIER FOR FRIDAY. HOWEVER, IF THE CLOSED LOW DOES FORM NEAR
THE AREA, IT WOULD LEAD TO MORE POTENTIALS FOR SHOWERS. INTO THE
WEEKEND, WE FEEL THE INFLUENCE OF A SURFACE HIGH OFF TO OUR
SOUTHEAST WHICH ALLOWS FOR DRIER CONDITIONS AND TEMPERATURES TO WARM
UP.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS...
THROUGH 12Z...PRIMARILY VFR. A FEW LIGHT SHOWERS OR BR COULD
LEAD TO BRIEF VISIBILITY RESTRICTIONS FOR THE I-95 TERMINALS,
MIV, AND ACY. WINDS GENERALLY NORTH AT 5-10 KT. MODERATE
CONFIDENCE.
TODAY...PRIMARILY VFR. A FEW LIGHT SHOWERS COULD LEAD TO BRIEF
VISIBILITY RESTRICTIONS FOR MIV AND ACY THROUGH 18-20Z BEFORE
ANY SHOWERS MOVE OFFSHORE. WINDS GENERALLY NORTH-NORTHWEST AT
5-10 KT. MODERATE CONFIDENCE.
TONIGHT...VFR. WINDS GENERALLY NORTHWEST AT 5 KT OR LESS. HIGH
CONFIDENCE.
OUTLOOK...
TUESDAY...VFR.
WEDNESDAY AND THURSDAY...A PERIOD OF SUB-VFR CONDITIONS POSSIBLE
ALONG WITH SHOWERS. A FEW THUNDERSTORMS POSSIBLE WEDNESDAY AFTERNOON
AND EVENING.
FRIDAY...VFR.
MARINE
WINDS AND SEAS SHOULD STAY BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH MONDAY. A FEW AREA ARE CURRENTLY SEEING WAVE HEIGHTS
NEAR 5 FT, BUT EXPECT WAVE HEIGHTS TO CONTINUE TO SUBSIDE. A
BRIEF PERIOD OF NORTHWESTERLY WIND GUSTS AT OR ABOVE 20 KT IS
POSSIBLE VERY LATE TONIGHT INTO TUESDAY MORNING, BUT IT IS
LIKELY TO REMAIN BELOW 25 KT.
OUTLOOK...
MONDAY NIGHT AND TUESDAY...THE CONDITIONS ARE ANTICIPATED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA.
WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED WITH WINDS OF
25-30 KT AND SEAS OF 4-6 FEET.
THURSDAY AND FRIDAY...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...AKL/COOPER/GUZZO/JOHNSON
AVIATION...COOPER/GORSE/GUZZO
MARINE...GORSE/GUZZO/JOHNSON
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