515
FXUS61 KPHI 010619
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
219 AM EDT WED APR 1 2026
WHAT HAS CHANGED
TEMPERATURES HAVE TRENDED COLDER FOR THURSDAY.
THE SMALL CRAFT ADVISORY FOR THE DELAWARE BAY HAS BEEN EXTENDED
TO 7 AM TODAY.
KEY MESSAGES
1. NEAR-RECORD WARMTH TODAY AND WEDNESDAY WILL BE ENDED
BY A COLD FRONT SLIDING INTO THE REGION BY WEDNESDAY NIGHT,
ACCOMPANIED BY SHOWERS AND THUNDERSTORMS.
2. A FAIRLY STRONG FRONT WILL BE LOCATED NEAR THE
REGION THURSDAY INTO FRIDAY LEADING TO THE POTENTIAL FOR A LARGE
TEMPERATURE GRADIENT ACROSS THE AREA AND ALONG WITH CONTINUING
CHANCES FOR SOME SHOWERS.
3. TEMPERATURES INCREASE INTO THE WEEKEND. A FEW
SHOWERS OR STORMS WILL BE POSSIBLE SATURDAY WITH MORE WIDESPREAD
SHOWERS AND STORMS EXPECTED FOR SUNDAY.
DISCUSSION
KEY MESSAGE 1...NEAR-RECORD WARMTH TODAY AND WEDNESDAY WILL BE ENDED
BY A COLD FRONT SLIDING INTO THE REGION BY WEDNESDAY NIGHT,
ACCOMPANIED BY SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE REMAINS SITUATED OFF THE EAST COAST THIS AFTERNOON
WHILE LOW PRESSURE IS MOVING THROUGH THE LOWER GREAT LAKES. THIS SET
UP IS KEEPING THE AREA IN A CONTINUING WARM SW FLOW WITH
TEMPERATURES AS OF 2 PM GENERALLY IN THE UPPER 70S TO AROUND 80
(EXCEPT COOLER RIGHT NEAR THE COAST AND OVER THE HIGHER TERRAIN OF
THE POCONOS AND NW NJ). MANY AREAS WILL LIKELY GAIN ANOTHER DEGREE
OR TWO BEFORE REACHING THEIR HIGH THUS BRINGING THESE NUMBERS TO
NEAR OR ABOVE RECORD VALUES FOR THIS DATE (SEE THE CLIMATE SECTION
BELOW. OTHERWISE, WITH THE WARM FRONT TO OUR NORTH, THIS IS WHERE
SHOWERS AND STORMS ARE AT THIS HOUR. THERE'S A SMALL CHANCE SOME OF
THESE COULD EVENTUALLY GET INTO OUR NW ZONES (LEIGH VALLEY, SOUTHERN
POCONOS INTO NW NJ) LATE THIS AFTERNOON INTO THIS EVENING BUT POPS
ARE ONLY AROUND 20 TO 30 PERCENT. IF SOME STORMS DO EVENTUALLY MAKE
IT IN, CAN'T RULE OUT A STRONG TO SEVERE STORM BUT AGAIN, CHANCES OF
ALL THIS COMING TOGETHER ARE PRETTY LOW. MAIN THREAT WOULD BE
DAMAGING WINDS.
GOING INTO THE OVERNIGHT HOURS OF TONIGHT, THE FRONT TO OUR
NORTH WILL DRAW A BIT CLOSER SO THIS WILL KEEP THE CHANCES FOR
SOME SHOWERS AND STORMS IN THE FORECAST FOR OUR N/W AREAS
DESPITE THE LOSS OF DAYTIME HEATING. OTHERWISE, WITH THE AREA
SQUARELY IN THE WARM SECTOR WITH CONTINUING SW FLOW THIS WILL
RESULT IN A VERY MILD NIGHT FOR THIS TIME OF YEAR WITH LOWS ONLY
GETTING DOWN INTO THE 60S.
FOR WEDNESDAY, THE COLD FRONT TO OUR NORTH STARTS ADVANCING INTO OUR
AREA...REACHING N/W ZONES AROUND LATE MORNING (10AM - NOON), THE I-
95 CORRIDOR AROUND LATE AFTERNOON, AND THEN MOVING THROUGH DELMARVA
THROUGH THE COURSE OF THE EVENING. WHERE THE FRONT IS NOT EXPECTED
TO CLEAR THE AREA UNTIL VERY LATE DAY OR IN THE EVENING, EXPECT
HIGHS GETTING BACK INTO THE UPPER 70S TO MID 80S. THIS ESSENTIALLY
INCLUDES MOST AREAS NEAR AND SOUTH OF THE I-95 CORRIDOR (EXCEPT
RIGHT ALONG THE COAST WHERE IT WILL BE COOLER). HEADING FARTHER
NORTH THOUGH IT WILL BE COOLER WITH THE POCONOS AND NW NJ LIKELY
SEEING HIGHS ONLY SEEING HIGHS IN THE 60S TO AROUND 70. THE COLD
FRONT ALONG WITH DAYTIME HEATING WILL BRING AN INCREASING CHANCES
(POPS 60 TO 80 PERCENT) FOR SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON INTO THE EVENING HOURS. ML CAPE VALUES OVER SE PA INTO
SOUTHERN NJ AND DELMARVA COULD TOP OUT AROUND 1000 J/KG ALONG WITH
MODEST MID LEVEL FLOW AND SHEAR VALUES (WINDS IN THE 700-500 MB
LAYER AROUND 35 TO 40 KNOTS). A LIMITING FACTOR THOUGH IS THAT THE
ADVANCING FRONT MAY TEND TO UNDERCUT THE DEVELOPING SHOWERS/STORMS
RESULTING IN THEM BECOMING MORE WIDESPREAD ON THE COOLER SIDE OF THE
BOUNDARY. THIS ALL SAID, THE STORM PREDICTION CENTER HAS EXPANDED
THE MARGINAL RISK FOR SEVERE STORMS FOR WEDNESDAY INTO WEDNESDAY
EVENING OVER SE PA, ROUGHLY THE SOUTHERN HALF OF NJ, AND DELMARVA.
THIS MEANS ISOLATED SEVERE STORMS WILL BE POSSIBLE WITHIN THIS AREA.
THE MAIN THREAT WILL BE DAMAGING WINDS. IT'S ALSO WORTH NOTING THAT
PWAT VALUES WILL BE INCREASING TO AROUND 1.25 TO 1.5 INCHES AND
THERE WILL ALSO MAY BE A TENDENCY FOR STORMS TO TRAIN A BIT DURING
THE LATE AFTERNOON INTO THE EVENING. FOR THIS REASON, CAN'T RULE OUT
SOME LOCALIZED FLOODING ISSUES...ESPECIALLY IF HEAVIER STORMS
OCCUR OVER THE URBAN CORRIDOR.
KEY MESSAGE 2...A FAIRLY STRONG FRONT WILL BE LOCATED NEAR THE
REGION THURSDAY INTO FRIDAY LEADING TO THE POTENTIAL FOR A LARGE
TEMPERATURE GRADIENT ACROSS THE AREA AND ALONG WITH CONTINUING
CHANCES FOR SOME SHOWERS.
OUR COLD FRONT FROM WEDNESDAY LOOKS TO STALL OVER SOUTHERN DELMARVA
FOR THURSDAY KEEPING THE AREA ON THE COOL SIDE OF IT ALONG WITH
MAINLY CLOUDY SKIES AND EAST WINDS. THERE COULD BE SOME LIGHT
SHOWERS AROUND OR EVEN SOME PATCHY DRIZZLE BUT IT WILL BE TOO STABLE
FOR ANY THUNDERSTORMS. WITH CONFIDENCE INCREASING IN THE FRONT BEING
FARTHER SOUTH, OUR TEMPERATURE FORECAST FOR THURSDAY HAS TRENDED
COLDER. IN FACT PORTIONS OF NE PA INTO NORTHERN NJ THAT ARE FORECAST
TO GET DOWN INTO THE 40S FOR WEDNESDAY NIGHT MAY REMAIN STUCK IN THE
40S FOR THURSDAY. FARTHER SOUTH, GENERALLY EXPECT HIGHS IN THE 50S
OVER SE PA INTO SOUTHERN NJ BUT EVEN THESE TEMPERATURES COULD BE A
BIT OPTIMISTIC AS THERE'S SOME GUIDANCE THAT'S EVEN COOLER. CLOSER
TO THE FRONT OVER OUR DELMARVA ZONES, IT LOOKS TO GENERALLY GET INTO
THE 60S WITH THESE AREAS ALSO HAVING THE BEST CHANCES FOR SEEING
SOME SUNSHINE.
THE FRONT DOESN'T LOOK TO MAKE MUCH PROGRESS NORTH FOR THURSDAY
NIGHT SO MANY AREAS SHOULD SEE LOWS IN THE 40S EXCEPT SOME LOW/MID
50S OVER PORTIONS OF DELMARVA. SOME SPOTTY LIGHT SHOWERS WILL BE
POSSIBLE BUT OTHERWISE NOT EXPECTING MUCH IN THE WAY OF PRECIP. THE
FRONT SHOULD FINALLY LIFT BACK NORTHWARD ON FRIDAY BUT IT'S PROGRESS
MAY BE A BIT SLOWER THAN PREVIOUS THINKING. NEVERTHELESS, EXPECT
THAT BY AFTERNOON WE'LL BE BACK INTO THE S/SW FLOW AS THE FRONT
LIFTS NORTH WITH HIGHS GENERALLY IN THE 70S. WITH A BIT MORE OF A
SOUTHERLY COMPONENT TO THE WIND IT WILL BE COOLER NEAR THE COAST AND
POTENTIALLY EXTENDING A BIT FARTHER INLAND COMPARED TO TODAY AND
WEDNESDAY. HIGHS FOR THESE COASTAL AREAS MAY ONLY REACH THE LOW/MID
60S. CAN'T RULE OUT A FEW SHOWER OR STORMS FOR FRIDAY BUT OVERALL IT
LOOKS TO BE DRY.
KEY MESSAGE 3...TEMPERATURES INCREASE INTO THE WEEKEND. A FEW
SHOWERS OR STORMS WILL BE POSSIBLE SATURDAY WITH MORE WIDESPREAD
SHOWERS AND STORMS EXPECTED FOR SUNDAY.
WE SHOULD REMAIN LARGELY IN THE WARM SECTOR FOR SATURDAY AS ONE LOW
WILL BE PULLING AWAY AS IT MOVES INTO THE CANADIAN MARITIMES WHILE A
STRONGER LOW ADVANCES INTO THE GREAT LAKES REGION. THIS SHOULD HELP
KEEP US IN THE S/SW FLOW WITH HIGHS SATURDAY LIKELY A BIT WARMER
THAN FRIDAY...GENERALLY IN THE 70S TO LOW 80S. HOWEVER THE FRONT MAY
WAVER NEAR OUR NORTHERN ZONES OR EVEN MAKE IT SLIGHTLY INTO OUR AREA
AT TIMES SO THIS WILL ONCE AGAIN KEEP THE CHANCE FOR SOME
SHOWER/STORMS IN THE FORECAST. THIS WILL BE MAINLY FOR AREAS N/W OF
THE URBAN CORRIDOR THOUGH WITH POPS STILL ONLY AROUND 20 TO 30
PERCENT.
THE BETTER COVERAGE OF RAIN SHOWERS ARRIVES SUNDAY (POPS 60-70
PERCENT) WITH A STRONG COLD FRONT MOVING THROUGH. AHEAD OF THE COLD
FRONT, HIGHS ARE IN THE 70S FOR MANY SPOTS WITH 60S IN THE POCONOS
AND ALONG THE COAST. BEHIND THE COLD FRONT, LOWS ARE IN THE MID 30S
TO MID 40S. ON MONDAY HIGHS REACH THE UPPER 40S TO MID 50S.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TONIGHT...PRIMARILY VFR. A FEW SHOWERS ARE POSSIBLE AT
KABE/KRDG. LLWS FOR MOST TERMINALS OUT OF THE SOUTHWEST AT
AROUND 40-45 KTS. MODERATE CONFIDENCE.
WEDNESDAY...MOSTLY VFR WITH W TO SW WINDS AROUND 10 KNOTS WITH
KMIV/KACY SEEING WINDS OF 10-15 KNOTS AND GUSTS TO 20 KNOTS. DUE
TO THE ISOLATED TO WIDELY SCATTERED COVERAGE OF SHOWERS, VCSH
AND PROB30 GROUPS WERE USED. MORE COVERAGE EXPECTED AROUND 00Z
AS THE FRONT APPROACHES AND -SHRA WAS ADDED. THERE IS THE
POTENTIAL FOR ISOLATED THUNDERSTORMS, BUT DUE TO COVERAGE AND
TIMING, THUNDER HAS BEEN LEFT OUT OF THE TAFS. MODERATE
CONFIDENCE.
WEDNESDAY NIGHT....MVFR TO POTENTIALLY IFR DUE TO LOW CEILINGS.
WINDS TURN TO BE OUT OF THE NORTH TO NORTHEAST AT AROUND 10
KNOTS OR LESS. SCATTERED RAIN SHOWERS CONTINUE WITH PREVAILING
-SHRA IN THE TAFS. ISOLATED THUNDERSTORMS REMAIN POSSIBLE BUT
DUE TO TIMING AND LOW CONFIDENCE, THERE IS NO THUNDER IN THE TAFS.
MODERATE CONFIDENCE.
OUTLOOK...
THURSDAY...SUB-VFR CONDITIONS LIKELY WITH WIDESPREAD SHOWERS
AND SCATTERED THUNDERSTORMS MOVING THROUGH.
THURSDAY NIGHT THROUGH SUNDAY...PRIMARILY VFR, BUT SUB-VFR
POSSIBLE IN ANY RAIN SHOWERS.
MARINE
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL ATLANTIC COASTAL
WATERS UNTIL 6 PM TODAY. THE SMALL CRAFT ADVISORY FOR THE
DELAWARE BAY HAS BEEN EXTENDED TO 7 AM TODAY.
SOUTH-SOUTHWEST WINDS AROUND 10-20 KT ARE EXPECTED TO CONTINUE INTO
THIS MORNING WITH OCCASIONAL GUSTS AROUND 25-30 KT. SEAS WILL
LARGELY RANGE BETWEEN 5-7 FEET. WINDS RELAX A BIT TODAY AND
REMAIN OUT OF THE SOUTH-SOUTHWEST AT 10-15 KT WITH GUSTS TO 20
KT. SEAS REMAIN ELEVATED AT 5-6 FEET THROUGH MUCH OF THE DAY.
THERE IS ALSO THE RISK OF SHOWERS/T-STORMS WHICH WILL INCREASE
INTO THE EVENING HOURS.
FOR TONIGHT, GENERALLY SUB-SCA CONDITIONS AS SEAS ARE MAINLY 3-4
FEET. WINDS TURN TO BE OUT OF THE NORTHEAST AT AROUND 10 KT
WITH GUSTS TO 15 KT. THE EXCEPTION IS THE NORTHERN TWO ATLANTIC
COASTAL MARINE ZONES WHICH HAVE THE POTENTIAL TO SEE SMALL
CRAFT ADVISORY CONDITIONS. WINDS OUT OF THE NORTHEAST AT 15-20
KT WITH GUSTS TO 25 KT FOR THESE MARINE ZONES AND SEAS 5-6 FEET.
THE RISK OF SHOWERS AND THUNDERSTORMS CONTINUES OVERNIGHT FOR
ALL MARINE ZONES.
OUTLOOK...
THURSDAY THROUGH FRIDAY NIGHT...SEAS WILL BE LINGERING AROUND 4
TO 5 FEET FOR MUCH OF THIS PERIOD. GENERALLY SUB SCA WINDS
EXCEPT A PERIOD OF STRONGER EAST WINDS LIKELY LATER WEDNESDAY
NIGHT INTO THURSDAY MORNING OFF THE COAST OF MONMOUTH AND OCEAN
COUNTIES.
SATURDAY...CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY
CRITERIA.
SUNDAY...SMALL CRAFT ADVISORY LEVEL WINDS PROBABLE.
CLIMATE
THE WARMTH IS FORECAST TO SURGE INTO OUR AREA DURING THE FIRST
HALF OF THIS WEEK. GIVEN THE CURRENT FORECAST, SOME INLAND AREAS
COULD CHALLENGE THEIR RECORD HIGH TEMPERATURES ON TUESDAY (MARCH
31) AND WEDNESDAY (APRIL 1).
LOCATION RECORD HIGH 3/31
-------- ---------------
ACY ATLANTIC CITY, NJ 85/1979
PHL PHILADELPHIA, PA 82/2025
ILG WILMINGTON, DE 82/1998
ABE ALLENTOWN, PA 86/1998
TTN TRENTON, NJ 84/1910
RDG READING, PA 86/1998
GED GEORGETOWN, DE 82/1998
MPO MOUNT POCONO, PA 81/1998
55N AC MARINA, NJ 73/1936
LOCATION RECORD WARMEST LOW 3/31
-------- ---------------
ACY ATLANTIC CITY, NJ 58/1998
PHL PHILADELPHIA, PA 61/1998
ILG WILMINGTON, DE 57/1979
ABE ALLENTOWN, PA 52/1981
TTN TRENTON, NJ 60/1998
RDG READING, PA 57/1998
GED GEORGETOWN, DE 64/1998
MPO MOUNT POCONO, PA 51/1998
55N AC MARINA, NJ 56/1998
LOCATION RECORD HIGH 4/1
-------- ---------------
ACY ATLANTIC CITY, NJ 80/1978
PHL PHILADELPHIA, PA 81/1978
ILG WILMINGTON, DE 81/1978
ABE ALLENTOWN, PA 84/1978
TTN TRENTON, NJ 81/1986
RDG READING, PA 82/1917
GED GEORGETOWN, DE 80/1979
MPO MOUNT POCONO, PA 81/1998
55N AC MARINA, NJ 72/1955
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ430-
431.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ450>455.
DISCUSSION...FITZSIMMONS/RCM
AVIATION...GUZZO/OHARA
MARINE...FITZSIMMONS/GUZZO/RCM
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