377
FXUS61 KPHI 230629
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
229 AM EDT THU APR 23 2026
WHAT HAS CHANGED
INCREASED FIRE WEATHER CONCERN FOR TODAY.
KEY MESSAGES
1. WARM TEMPERATURES, LOW HUMIDITY AND AN AFTERNOON BREEZE WILL
RESULT IN ELEVATED FIRE WEATHER CONCERNS TODAY.
2. A WAVE OF LOW PRESSURE WILL BRING WIDESPREAD RAINFALL TO THE
REGION THIS WEEKEND WITH SEASONABLY COOL TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...WARM TEMPERATURES, LOW HUMIDITY AND AN
AFTERNOON BREEZE WILL RESULT IN ELEVATED FIRE WEATHER CONCERNS
TODAY.
HIGH PRESSURE BUILDS BOTH OVER HUDSON BAY IN CANADA AND OVER
THE MID-ATLANTIC AND SOUTHEAST TODAY. WINDS TURN TO THE WEST-
NORTHWEST AND WILL INCREASE TO 10 TO 15 MPH WITH GUSTS UP TO 25
MPH IN THE AFTERNOON. SKIES WILL BE SUNNY AFTER ANY PATCHY LOW
CLOUDS AND FOG BURN OFF, AND IT WILL BE QUITE WARM WITH HIGHS
IN THE MID TO UPPER 70S, THOUGH SOME SPOTS ALONG THE I-95
CORRIDOR AND INTERIOR PORTIONS OF DELMARVA MAY TOP OFF AROUND
80.
SURFACE DEW POINTS WILL START OUT CLOSE TO 50, THEN WILL MIX
DOWN TO THE LOW 40S AND EVEN UPPER 30S WITH EFFICIENT MIXING.
THIS RESULTS IN MINRH VALUES FROM 25 TO 35 PERCENT AWAY FROM
THE COASTS. GIVEN THIS, HAVE REACHED OUT TO FIRE WEATHER
PARTNERS REGARDING ANY CONCERNS WHICH MAY JUSTIFY A SPECIAL
WEATHER STATEMENT, BUT ANY FEEDBACK IS LIKELY SEVERAL HOURS
AWAY.
KEY MESSAGE 2...A WAVE OF LOW PRESSURE WILL BRING WIDESPREAD
RAINFALL TO THE REGION THIS WEEKEND WITH SEASONABLY COOL
TEMPERATURES.
A BACK DOOR COLD FRONT SINKS SOUTH OF THE AREA ON FRIDAY AS HIGH
PRESSURE SETTLES TO THE NORTH IN CANADA. A FEW SHOWERS MAY DEVELOP
IN THE AFTERNOON AS SOME MID-LEVEL ENERGY EMBEDDED IN THE NORTHWEST
FLOW ALOFT CLIPS THE REGION, BUT OVERALL CONDITIONS LOOK TO BE
MAINLY DRY AND COOL. FORECAST HIGHS ON FRIDAY WILL MAINLY BE IN THE
60S TO AROUND 70, PERHAPS PUSHING INTO THE MID 70S NEAR THE EASTERN
SHORE OF MD. IT SHOULD BE NOTED THAT FORECAST GUIDANCE NOTORIOUSLY
STRUGGLES WITH BACK DOOR FRONTS AND IT IS ENTIRELY POSSIBLE THAT THE
FRONT SINKS THROUGH MUCH FASTER THAN CURRENTLY PROGGED. THIS WOULD
RESULT IN MUCH COOLER TEMPERATURES THAN WHAT IS CURRENTLY IN THE
FORECAST.
A LOW PRESSURE SYSTEM ORGANIZING NEAR THE GREAT LAKES REGION FRIDAY
NIGHT WILL MOVE THROUGH THE REGION THIS WEEKEND. THE LATEST TREND
HAS BEEN FOR THE BULK OF THE RAIN SHOWERS TO BE SATURDAY WITH SUNDAY
TRENDING DRIER. HOWEVER, SOME MODEL GUIDANCE DOES STILL HAVE SOME
SHOWERS LINGERING ON SUNDAY, SO I HAVE KEPT SLIGHT CHANCE TO CHANCE
POPS FOR SUNDAY. CURRENT RAINFALL AMOUNTS LOOK TO TOTAL AROUND 0.50-
1.0 INCH TO THE NORTH OF PHILADELPHIA AND AROUND 0.25-0.50 INCHES TO
THE SOUTH OF PHILADELPHIA.
SATURDAY WILL BE DREARY, DAMP, AND COOL WITH HIGHS ONLY IN THE UPPER
40S TO UPPER 50S. SOME IMPROVEMENT SHOULD BE EXPECTED FOR SUNDAY,
BUT IT IS FULLY DEPENDENT ON HOW QUICKLY OUR LOW PRESSURE SYSTEM
EXITS. FOR SUNDAY, TEMPERATURES INCREASE INTO THE MID 50S TO MID
60S. BY EARLY NEXT WEEK, WE TREND WARMER THAN THE WEEKEND. MONDAY IS
LOOKING DRY WITH OUR NEXT SYSTEM APPROACHING MONDAY NIGHT AND
BRINGING RAIN SHOWERS TO THE AREA INTO MIDWEEK.
AVIATION /06Z THURSDAY THROUGH MONDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THRU 12Z THIS MORNING...MAINLY VFR. SOME PATCHY LOW CLOUDS OR
FOG/MIST MAY DEVELOP AT THE TERMINALS OTHER THAN KPHL, BUT RIGHT
NOW THE ONLY TAF WHICH EVEN HINTS AT IT IS KMIV AS CONFIDENCE IS
PRETTY LOW. MODERATE CONFIDENCE.
TODAY...ANY PATCHY FOG AND STRATUS WILL LIFT AND DISSIPATE
SHORTLY AFTER SUNRISE, WITH VFR PREVAILING. NW WINDS 5 TO 10
KT, INCREASE TO 10 TO 15 KT WITH GUSTS UP TO 20 KT IN THE
AFTERNOON. MODERATE CONFIDENCE.
TONIGHT...VFR WITH MAINLY SOME HIGH CLOUDS. WINDS SHIFTING TO
THE N BUT REDUCING TO 5-10 KTS. HIGH CONFIDENCE.
OUTLOOK...
FRIDAY THROUGH FRIDAY NIGHT...PRIMARILY VFR EXPECTED WITH A CHANCE
OF RAIN SHOWERS ON FRIDAY NIGHT.
SATURDAY THROUGH SATURDAY NIGHT...SUB-VFR CONDITIONS LIKELY. RAIN
SHOWERS LIKELY, ESPECIALLY SATURDAY AFTERNOON INTO SATURDAY NIGHT.
PATCHY FOG POSSIBLE.
SUNDAY...VFR EXPECTED. A SLIGHT CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT THROUGH MONDAY...VFR. NO SIGNIFICANT WEATHER.
MONDAY NIGHT THROUGH TUESDAY...SUB-VFR CONDITIONS POSSIBLE WITH RAIN
SHOWERS AND LOW CLOUDS.
MARINE
SUB-SMALL CRAFT ADVISORY CONDITIONS THROUGH TONIGHT. NE WINDS 5
TO 10 KT EARLY BECOME THEN NW 10 TO 15 KT LATER THIS MORNING,
THEN BECOME S IN THE AFTERNOON BEHIND AFTERNOON SEA BREEZES.
SEAS OVERALL 2 TO 4 FEET. WINDS SHIFT BACK TO N 5-10 KTS
TONIGHT.
VSBY RESTRICTIONS POSSIBLE IN FOG, MOSTLY NEAR THE COASTS, EARLY
THIS MORNING.
OUTLOOK...
FRIDAY THROUGH FRIDAY NIGHT...NO MARINE HEADLINES EXPECTED.
WINDS AROUND 5-15 KT WITH SEAS OF 2-3 FEET.
SATURDAY THROUGH SUNDAY NIGHT...SCA CONDITIONS LIKELY TO DEVELOP BY
SATURDAY EVENING. WINDS AROUND 15-20 KT WITH GUSTS UP TO 25 KT
POSSIBLE. SEAS OF 4-7 FEET. RAIN SHOWERS LIKELY.
MONDAY THROUGH MONDAY NIGHT...NO MARINE HEADLINES EXPECTED. WINDS
GENERALLY 10-15 KT AND SEAS 2-4 FEET.
TUESDAY...NO MARINE HEADLINES EXPECTED. WINDS AROUND 10-15 KT WITH
GUSTS TO 20 KT. SEAS OF 2-4 FEET. CHANCE FOR RAIN SHOWERS.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...DESILVA/GUZZO/MPS/RCM
AVIATION...DESILVA/GUZZO/MJL/MPS/RCM
MARINE...DESILVA/GUZZO/MPS/RCM
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