548
FXUS61 KPHI 230516
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
116 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 WILL SINK SOUTH THROUGH THE REGION ON
FRIDAY AS HIGH PRESSURE SETTLES NEAR NEW ENGLAND. A FEW SHOWERS
MAY DEVELOP IN THE AFTERNOON AS SOME 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.
LOW PRESSURE WILL THEN BEGIN TO ORGANIZE OVER THE GREAT LAKES
REGION BY FRIDAY NIGHT AND PUSH TOWARD THE NORTHEAST AND MID-
ATLANTIC REGION OVER THE WEEKEND. AS OF NOW, THERE ARE STILL
SOME TIMING DIFFERENCES ON HOW QUICKLY THE LOW TRACKS THROUGH
THE MID-ATLANTIC. SOME GUIDANCE INDICATES A QUICK MOVING LOW
THAT WILL BE OFF THE COAST BY SUNDAY, WHEREAS SOME DEPICT A
SLOWER MOVING LOW THAT WON'T MOVE OFF THE COAST UNTIL SUNDAY
NIGHT. FOR THIS REASON, HAVE CARRIED AT LEAST A CHANCE OF POPS
THROUGH THE ENTIRE WEEKEND, WITH THE MOST LIKELY TIMING OF
PRECIP BEING SATURDAY AFTERNOON AND EVENING. WHILE NOT EXPECTING
A WASHOUT BOTH DAYS, SHOWERS WILL LIKELY BE AROUND AT TIMES.
CURRENT RAINFALL AMOUNTS LOOK TO TOTAL AROUND 0.5-1.0 INCHES TO
THE NORTH OF PHILADELPHIA AND AROUND 0.1-0.5 INCHES TO THE SOUTH
OF PHILADELPHIA.
SATURDAY WILL BE DREARY, DAMP, AND RAW WITH HIGHS ONLY IN THE
UPPER 40S TO UPPER 50S. SOME IMPROVEMENT SHOULD BE EXPECTED BY
SUNDAY (THOUGH IS DEPENDENT ON LOW TIMING MENTIONED ABOVE), WITH
TEMPS INCREASING INTO THE MID 50S TO MID 60S. BY EARLY NEXT
WEEK, DRY AND WARMER CONDITIONS RETURN WITH HIGHS RETURNING BACK
TO NORMAL.
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 SUNDAY...SUB-VFR CONDITIONS LIKELY. RAIN
SHOWERS LIKELY, ESPECIALLY SATURDAY AFTERNOON INTO SATURDAY
NIGHT. PATCHY FOG POSSIBLE.
SUNDAY NIGHT THROUGH MONDAY...VFR EXPECTED. A SLIGHT CHANCE OF
RAIN SHOWERS.
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...
THURSDAY NIGHT 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 AFTERNOON. WINDS AROUND 15-25 KT WITH GUSTS UP TO 30 KT
POSSIBLE. SEAS OF 4-7 FEET. RAIN SHOWERS LIKELY.
MONDAY...LINGERING SCA CONDITIONS POSSIBLE. WINDS GENERALLY AROUND
15-20 KT WITH SEAS OF 3-5 FEET.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...DESILVA/MPS/RCM
AVIATION...DESILVA/MJL/MPS/RCM
MARINE...DESILVA/MPS/RCM
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