657
FXUS61 KPHI 010728
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
328 AM EDT TUE APR 1 2025
SYNOPSIS
A COLD FRONT WILL MOVE OUT TO SEA TODAY. COOL AND DRY HIGH
PRESSURE WILL SETTLE INTO THE AREA THROUGH WEDNESDAY, THEN MOVES
QUICKLY OFFSHORE. A WARM FRONT WILL LIFT NORTH WEDNESDAY NIGHT
INTO THURSDAY. THIS FRONT WILL RETURN SOUTH THROUGH THE AREA
LATE FRIDAY, THEN LOW PRESSURE WILL PASS OFFSHORE OVER THE
WEEKEND, KEEPING GENERALLY UNSETTLED CONDITIONS IN PLACE THROUGH
THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
155 AM...THE COLD FRONT IS BEGINNING TO WORK ITS WAY ACROSS THE
REGION AND WILL MOVE OFFSHORE BEFORE DAWN. THIS WILL BRING THE
LINGERING RAIN TO AN END FROM WEST TO EAST. BEHIND THE FRONT, NW
WINDS WILL INCREASE TO AROUND 15 GUSTING 20 TO 30 MPH AT TIMES.
BY MORNING, EXPECT LOWS RANGING FROM THE MID TO UPPER 30S NORTH
TO THE MID/UPPER 40S SOUTH.
FOR THE DAY TUESDAY, WE WILL STILL BE IN A POST FRONTAL, COLD
ADVECTION REGIME WITH 850 MB TEMPERATURES DROPPING TO AROUND -4C
TO 2C. THIS WILL TRANSLATE TO HIGH TEMPERATURES GENERALLY
RANGING FROM THE MID TO UPPER 50S NEAR AND SOUTH OF THE URBAN
CORRIDOR WITH LOW 50S FOR MOST AREAS FARTHER NORTH, EXCEPT 40S
IN THE HIGHER ELEVATIONS. BREEZY NW WINDS AROUND 10 TO 15 WITH
GUSTS UP TO 25 MPH WILL CONTINUE THROUGH THE EARLY AFTERNOON
BEFORE SLOWLY STARTING DO DIMINISH AS SURFACE HIGH PRESSURE
BUILDS IN TO OUR NORTH AND THE GRADIENT WEAKENS.
HIGH PRESSURE TO OUR NORTH WILL BEGIN SHIFTING EAST TUESDAY
NIGHT WHICH WILL LEAD TO SURFACE WINDS BECOMING MORE
NORTHEASTERLY. WINDS SHOULD REMAIN ELEVATED ENOUGH ON THE OUTER
PERIPHERY OF THE HIGH AROUND 5- 10 MPH, BUT THE USUAL SHELTERED
SPOTS WILL LIKELY GO CALM AND RADIATE WELL UNDER MOSTLY CLEAR
SKIES. THIS IS NOTEWORTHY BECAUSE THE FROST/FREEZE PROGRAM
BEGINS APRIL 1 FOR OUR DELMARVA COUNTIES. WITH THE DRY AIRMASS
IN PLACE AND A COOL NORTHEAST BREEZE, THIS SHOULD LIMIT/PREVENT
ANY FROST DEVELOPMENT DESPITE THE LOW TEMPS IN THE MID TO UPPER
30S. FURTHER NORTH, LOWS WILL BE IN THE UPPER 20S TO MID 30S,
BUT THE GROWING SEASON IS NOT ACTIVE YET IN THESE LOCATIONS TO
WARRANT ANY FREEZE HEADLINES.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/
UPPER TROUGHING WILL PUSH OFFSHORE BY TUESDAY NIGHT, FOLLOWED
BY ZONAL FLOW FOR WEDNESDAY AND UPPER RIDGING FOR WEDNESDAY
NIGHT INTO THURSDAY. AT THE SURFACE, COOL AND DRY CANADIAN HIGH
PRESSURE WILL REMAIN ACROSS THE REGION INTO WEDNESDAY. A WARM
FRONT WILL THEN LIFT NORTH THROUGH THE AREA WEDNESDAY NIGHT AS A
STRONG LOW PASSES THROUGH THE NORTHERN GREAT LAKES ON THURSDAY.
FOR WEDNESDAY, THE HIGH WILL CONTINUE TO EXIT AND SHIFT OFF THE
COAST OF NEW ENGLAND. SHOULD SEE MOSTLY CLEAR SKIES EARLY IN
THE DAY, BECOMING MORE CLOUD-FILLED IN THE AFTERNOON. WINDS WILL
BECOME SOUTHEASTERLY DUE TO THE POSITIONING OF THE HIGH,
CAUSING A MORE ONSHORE COMPONENT. IT WILL ALSO BECOME BREEZY ON
WEDNESDAY WITH WINDS INCREASING TO 10-20 MPH WITH GUSTS LOCALLY
UP TO 30 MPH. HIGH TEMPERATURES SHOULD RANGE FROM THE UPPER 40S
TO UPPER 50S FROM NORTH TO SOUTH.
BY WEDNESDAY NIGHT AND THURSDAY, WE WILL BEGIN TO SEE
SIGNIFICANT CHANGES AROUND THE AREA. A WARM FRONT EXTENDING
EASTWARD FROM A STRONG AREA OF LOW PRESSURE TRACKING INTO THE
GREAT LAKES WILL SURGE NORTHWARD ACROSS OUR AREA ON WEDNESDAY
NIGHT. THIS WILL RESULT IN A RAMP UP IN WARM AIR AND MOISTURE
ADVECTION TO OCCUR. COULD SEE A FEW WARM AIR ADVECTION SHOWERS
OCCUR ESPECIALLY NORTH AND WEST OF THE I-95 CORRIDOR WITH THE
FRONTAL PASSAGE, BUT OVERALL ANY QPF SHOULD BE LIMITED. LOWS
WILL BE MUCH WARMER THAN THE NIGHT BEFORE WITH LOWS IN THE UPPER
30S TO 40S.
FOR THURSDAY, WILL HAVE SOME UPPER LEVEL ENERGY AROUND OFF TO
OUR NORTH AND WEST, SO HAVE KEPT A CHANCE OF SHOWERS IN THE
FORECAST CONTINUING INTO THURSDAY. NO THREAT FOR SEVERE
THUNDERSTORMS, WITH BETTER FORCING AND SHEAR DISPLACED WELL
AWAY FROM THE AREA, THOUGH CANNOT RULE OUT SOME THUNDER WITH ANY
SHOWERS. DESPITE MOSTLY CLOUDY TO OVERCAST SKIES AROUND, STRONG
SOUTHERLY WINDS ADVECTING WARMER AIR NORTHWARD SHOULD ALLOW
HIGHS TO RANGE FROM THE UPPER 60S TO UPPER 70S.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
LITTLE IN THE WAY OF CHANGES WERE MADE TO THE LONG TERM PERIOD
AS RIDGING OVER THE EASTERN US WILL BE IN PLACE LATE WEEK
THROUGH THE WEEKEND WITH AN UPPER LEVEL TROUGH MOVING BACK INTO
THE REGION EARLY NEXT WEEK.
LOW PRESSURE EXITS THE REGION THURSDAY NIGHT INTO THE CANADIAN
MARITIMES, WITH A LEFTOVER BOUNDARY REMAINING SITUATED TO THE
NORTH OF OUR AREA. THE BOUNDARY WILL GRADUALLY SINK SOUTHWARD
DURING THE DAY ON FRIDAY INTO FRIDAY NIGHT, WHILE REMAINING WELL
SOUTH OF THE AREA THROUGH THE WEEKEND. SEVERAL WEAK
DISTURBANCES WILL RIDE ALONG THIS BOUNDARY ACCOMPANIED WITH
UPPER LEVEL ENERGY PULSES THAT WILL OCCUR LATE WEEK AND THROUGH
THE WEEKEND. THIS WILL CAUSE A RATHER UNSETTLED WEATHER PERIOD
TO OCCUR LATE IN THE WEEK INTO THE WEEKEND, WHERE SEVERAL
ROUNDS OF SHOWERS ARE EXPECTED. THIS WILL PRESENT A PERIOD OF
RELATIVELY LOW PREDICTABILITY WITHIN THE LONG TERM FORECAST,
BUT GENERALLY EXPECTED AN EXTENDED PERIOD OF SHOWERY AND
UNSETTLED WEATHER CONDITIONS.
GIVEN THE NATURE OF THE PATTERN, ISOLATED THUNDERSTORMS WILL BE
POSSIBLE FOR THURSDAY NIGHT, BUT NOTHING IN TERMS OF SEVERE
WEATHER IS EXPECTED. A FEW RUMBLES OF THUNDER HERE OR THERE AT
MOST. HEADING INTO FRIDAY THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK, THE CHANCE FOR THUNDERSTORMS BECOMES LESS LIKELY AS
THE AIRMASS BECOMES MORE STABLE NORTH OF THE BOUNDARY. ALL IN
ALL, HAVE KEPT A CHANCE OF SHOWERS ACROSS THE ENTIRE FORECAST
AREA FRIDAY THROUGH MONDAY. NOT EXPECTING A WASHOUT BY ANY MEANS
AS THERE WILL BE SEVERAL BREAKS/LULLS IN BETWEEN THE ROUNDS OF
SHOWERS, BUT LONG STORY SHORT, IT WILL BE UNSETTLED INTO EARLY
NEXT WEEK.
IN TERMS OF TEMPERATURES, ANOTHER WARM DAY IS EXPECTED FRIDAY
BEFORE THE BOUNDARY PASSES THROUGH THE AREA, WITH HIGHS IN THE
MID 60S TO LOW 70S. WE WILL BECOME COOLER OVER THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPERATURES GENERALLY +/- 5 DEGREES
COMPARED TO NORMAL FOR EARLY APRIL.
LOOKING FARTHER AHEAD INTO NEXT WEEK, THE PATTERN WILL SUPPORT
A PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES. THE CLIMATE
PREDICTION CENTER PROJECTS A ~70% CHANCE OF BELOW NORMAL
TEMPERATURES FOR MUCH OF NEXT WEEK. THIS WILL PRESENT POTENTIAL
FOR FROST AND FREEZE HAZARDS ACROSS PORTIONS OF THE AREA, AS THE
FROST/FREEZE PROGRAM WILL BEGIN ON APRIL 11TH FOR AREAS SOUTH
OF I-78 INTO PA AND NJ. IT BEGINS TODAY (APRIL 1ST) FOR
DELMARVA.
AVIATION /07Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF OVERNIGHT...RAIN WINDS DOWN WEST TO EAST AS A COLD
FRONT CROSSES THE AREA BUT STILL EXPECT SOME SUB VFR
RESTRICTIONS ALONG AND JUST BEHIND THE FRONT UNTIL THE 7 TO 9Z
TIMEFRAME. WINDS NORTHWEST AROUND 10 TO 15 GUSTING UP TO 25
KNOTS. MODERATE CONFIDENCE.
TUESDAY...VFR WITH MAINLY CLEAR SKIES AND NW WINDS 10 TO 15
GUSTING 20 TO 25 KNOTS. HIGH CONFIDENCE.
TUESDAY NIGHT...REMAINING VFR WITH WINDS SHIFTING TO NORTHEAST
AND DIMINISHING TO AROUND 5 KNOTS. HIGH CONFIDENCE.
OUTLOOK...
WEDNESDAY...VFR. ASIDE FROM GUSTY SOUTHEAST WINDS, NO
SIGNIFICANT WEATHER EXPECTED.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MAINLY VFR EXPECTED
WITH OCCASIONAL SUB-VFR CONDITIONS POSSIBLE AT NIGHT. SLIGHT
CHANCE OF RAIN SHOWERS AND AN ISOLATED THUNDERSTORM. GUSTY SOUTH
WINDS.
FRIDAY THROUGH SATURDAY...SUB-VFR CONDITIONS POSSIBLE WITH A
CHANCE FOR RAIN SHOWERS.
MARINE
THE SMALL CRAFT ADVISORY CONTINUES UNTIL 1 PM TUESDAY FOR THE
DELAWARE BAY AND 6 PM TUESDAY FOR OUR OCEAN ZONES. FOR THE REST
OF THE OVERNIGHT PERIOD, SW WINDS WILL SHIFT TO NW AROUND 15 TO
20 GUSTING UP TO 30 KNOTS WITH SEAS MAINLY AROUND 5 TO 7 FEET.
THESE CONDITIONS WILL CONTINUE THROUGH TUESDAY MORNING BEFORE
GRADUALLY SUBSIDING AROUND MIDDAY THROUGH THE AFTERNOON.
THE WINDS SHIFT TO NORTHEAST TUESDAY NIGHT BUT THE CONDITIONS
SHOULD BE BELOW SMALL CRAFT ADVISORY LEVELS.
OUTLOOK...
WEDNESDAY...NO MARINE HEADLINES EXPECTED. FAIR WEATHER.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SCA CONDITIONS
PROBABLE DUE TO WIND GUSTS UP TO 30 KT AND SEAS AROUND 5-7 FEET.
SHOWERS AND ISOLATED THUNDERSTORMS LIKELY.
FRIDAY THROUGH SATURDAY...NO MARINE HEADLINES EXPECTED. PERIODS
OF RAIN SHOWERS LIKELY.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ430-
431.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ450>455.
SYNOPSIS...STAARMANN
NEAR TERM...FITZSIMMONS/MJL
SHORT TERM...DESILVA/STAARMANN
LONG TERM...DESILVA/STAARMANN
AVIATION...FITZSIMMONS/MJL/STAARMANN
MARINE...FITZSIMMONS/MJL/STAARMANN
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