253
FXUS61 KPHI 041945
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
345 PM EDT MON MAY 4 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
1. THERE IS A LIMITED RISK FOR FIRE WEATHER CONDITIONS THROUGH
TUESDAY.
2. A FEW SYSTEMS BRING SHOWERS TO THE AREA WEDNESDAY INTO
THURSDAY. ANOTHER WEAK SYSTEM COULD BRING SOME SHOWERS ON
SATURDAY.
DISCUSSION
KEY MESSAGE 1...THERE IS A LIMITED RISK FOR FIRE WEATHER
CONDITIONS TODAY.
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST CONTINUES TO
PUSH OFFSHORE THIS AFTERNOON LEADING TO SOUTHERLY FLOW ACROSS
THE REGION. WITH AN UPPER-LEVEL TROUGH OVER THE GREAT LAKES
ADVANCING A COLD FRONT TOWARDS THE REGION, WE HAVE SEEN
SUBSTANTIAL MIXING ACROSS INTERIOR LOCATIONS WITH SOUTHWESTERLY
WINDS IN THE 10-20 MPH RANGE WITH GUSTS 20-30 MPH. THIS PBL
MIXING HAS ALSO MIXED DOWN SOME LOWER DEWPOINTS AND LEAD TO
RELATIVE HUMIDITIES ALONG THE IMMEDIATE COAST IN THE 50-70%
RANGE AND AT AS LOW AS 25% FOR INLAND LOCATIONS.
THIS WILL CONTINUE AGAIN TUESDAY WITH WINDS STILL SW 10-20 MPH
GUSTING 25-35 MPH. PBL MIXING SHOULD AGAIN ALLOW FOR MINIMUM
RH'S TO DROP INTO THE 22-27% RANGE DURING THE DAY TUESDAY.
THESE PARAMETERS DO SUPPORT THE POTENTIAL SPREAD OF FIRES IF
THEY IGNITE. WILL CONTINUE TO COORDINATE WITH THE STATE FIRE
PARTNERS ON FUEL CONDITIONS BEFORE ANY ISSUANCE OF ANOTHER
SPECIAL WEATHER STATEMENT FOR TUESDAY AS GREEN UP IS IN FULL
EFFECT.
KEY MESSAGE 2...A FEW SYSTEMS BRING SHOWERS TO THE AREA WEDNESDAY
INTO THURSDAY. ANOTHER WEAK SYSTEM COULD BRING SOME SHOWERS ON
SATURDAY.
THE HIGH PRESSURE SYSTEM IS FINALLY DISPLACED ON TUESDAY, BUT
THE CONTINUED INFLUENCE FROM THE HIGH WILL KEEP MOST OF THE AREA
ON THE DRIER SIDE. ALSO DURING THIS TIMEFRAME, THERE WILL BE A
LOW PRESSURE SYSTEM WELL TO THE NORTH IN CANADA WITH A COLD
FRONT SINKING SOUTHEAST FROM THE GREAT LAKES REGION. OUR NW
AREAS HAVE THE POTENTIAL TO SEE AN ISOLATED SHOWER (20%) LATE
TUESDAY INTO TUESDAY NIGHT. THE BULK OF THE SHOWERS WILL MOVE
IN LATE TUESDAY NIGHT AND WEDNESDAY MORNING AND CONTINUE
THROUGH THE DAY WEDNESDAY AS THE COLD FRONT SINKS SOUTHEAST INTO
OUR AREA. THIS COLD FRONT THEN STALLS ACROSS THE REGION INTO
THURSDAY WITH A WAVE OF LOW PRESSURE MOVING NORTHWARD ALONG THE
FRONT LEADING TO MORE SHOWERS ON THURSDAY. THE MODEL TRENDS
TODAY IS FOR THE FRONT TO SHIFT FARTHER EAST AND OFFSHORE
THURSDAY, WITH SOME GUIDANCE MISSING MOST IF NOT ALL OF OUR AREA
WITH SHOWERS ASSOCIATED WITH LOW PRESSURE ALONG THE FRONT.
WHILE SOME GUIDANCE STILL ATTEMPTED TO BRING SOME CONVECTIVE
ELEMENTS TO THE REGION, THE CONSENSUS IS THAT WE WILL SEE
LOW INSTABILITY AND LIMITED TO ZERO SEVERE/FLOODING THREAT.
OVERALL, THIS WILL BE MORE BENEFICIAL RAIN FOR THE AREA WITH AN
ISOLATED THUNDERSTORM POSSIBLE.
FOR SATURDAY, A WEAK AREA OF LOW PRESSURE WILL MOVE INTO THE REGION,
POTENTIALLY PRODUCING SOME SHOWERS. THIS APPEARS TO BE NOTHING
MORE THAN A POTENTIAL WEEKEND SPOILER WITH NO SIGNIFICANT IMPACTS
EXPECTED AT THIS TIME.
AVIATION /19Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON...VFR. SOUTHWEST TO SOUTH WINDS 10-15
KNOTS WITH GUSTS 20-25 KNOTS. HIGH CONFIDENCE.
TONIGHT...VFR. SOUTH WINDS 10 KNOTS OR LESS. AS THE WINDS
DECOUPLE AT THE SURFACE TONIGHT, A MODEST LOW-LEVEL JET WILL
MOVE IN AND LEAD TO LOW-LEVEL WIND SHEAR DURING THE OVERNIGHT
HOURS. HIGH CONFIDENCE.
TUESDAY...VFR. SOUTH TO SOUTHWEST WINDS 10-20 KNOTS WITH GUSTS
25-30 KNOTS. MODERATE CONFIDENCE.
OUTLOOK...
TUESDAY NIGHT...PRIMARILY VFR. SOME SHOWERS POSSIBLE NORTH AND
WEST OF THE I-95 TERMINALS. GUSTY SOUTH/SOUTHWEST WINDS
GRADUALLY DIMINISHING.
WEDNESDAY THROUGH THURSDAY...MVFR/IFR CONDITIONS EXPECTED WITH
PERIODS OF RAIN, AN ISOLATED THUNDERSTORM, AND LOW CLOUDS.
SOUTHERLY WIND GUSTS AROUND 20-25 KT ON WEDNESDAY.
THURSDAY NIGHT...CONDITIONS IMPROVING BUT LINGERING
RESTRICTIONS POSSIBLE (30-40%).
FRIDAY...VFR. NO SIGNIFICANT WEATHER.
SATURDAY...SUB-VFR CONDITIONS AND SHOWERS POSSIBLE.
MARINE
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TUESDAY. SOUTH
TO SOUTHWEST WIND GUSTS WILL INCREASE UP TO 30 KNOTS INTO
TUESDAY. SEAS WILL ALSO BUILD.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...A SMALL CRAFT ADVISORY IS IN
PLACE FOR ALL MARINE ZONES. WIND GUSTS UP TO 30 KNOTS OUT OF
THE SOUTH/SOUTHWEST AND SEAS 4 TO 7 FEET.
WEDNESDAY NIGHT THROUGH THURSDAY...SCA CONDITIONS COULD LINGER
AS WINDS DECLINE BUT SEAS COULD NEAR 5 FEET.
THURSDAY NIGHT THROUGH SATURDAY...NO MARINE HEADLINES EXPECTED.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 2 AM EDT WEDNESDAY
FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ450>452.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ453>455.
DISCUSSION...DEAL/GORSE/HOEFLICH/MPS
AVIATION...GORSE/HOEFLICH/MPS
MARINE...HOEFLICH/MPS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page