809
FXUS61 KPHI 100740
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
240 AM EST SUN NOV 10 2024
SYNOPSIS
A WARM FRONT WILL LIFT THROUGH AND NORTH OF OUR REGION TODAY,
AHEAD OF A COLD FRONT THAT CROSSES THROUGH ON MONDAY. A
SECONDARY COLD FRONT FOLLOWS FOR TUESDAY BEFORE HIGH PRESSURE
RETURNS WEDNESDAY. ANOTHER PAIR OF A WARM FRONT THEN A WEAK
COLD FRONT MAY MOVE THROUGH THE REGION ON THURSDAY. HIGH
PRESSURE IS EXPECTED TO BUILD IN OVER THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
HIGH PRESSURE REMAINS CENTERED NEAR THE AREA EARLY THIS MORNING BUT
WILL START TO PUSH EASTWARD OUT TO SEA AS WE GET INTO THE DAY
SUNDAY. THIS WILL OCCUR AS LOW PRESSURE MOVES NORTH AND EASTWARD
THROUGH THE DAY SUNDAY PUSHING A WARM FRONT TOWARDS THE AREA. THERE
IS CURRENTLY SOME HIGH CLOUDINESS JUST STARTING TO PUSH INTO THE
AREA AND EXPECT THIS TO THICKEN AND GRADUALLY LOWER AS WE GO THROUGH
THE DAY SUNDAY. MOST OF THE DAY SHOULD REMAIN DRY, HOWEVER, UNTIL
SOME SHOWERS START PUSHING INTO OUR EASTERN PA ZONES TOWARDS THE
LATE AFTERNOON INTO THE EARLY EVENING. AFTER A CHILLY START,
GENERALLY EXPECT HIGHS SUNDAY RANGING FROM THE UPPER 50S NORTH TO
THE LOW TO MID 60S SOUTH.
RAIN WILL QUICKLY OVERSPREAD THE ENTIRE AREA AS WE GO THROUGH SUNDAY
EVENING AND THE WARM FRONT PUSHES THROUGH. THIS WILL OCCUR AS LOW
PRESSURE CONTINUES TO ADVANCE NORTH AND EASTWARD THROUGH THE
NORTHERN GREAT LAKES. THIS WILL BE OUR FIRST "WETTING RAIN" SINCE
THE END OF SEPTEMBER SO IT IS MUCH NEEDED! THE RAIN MAY BRIEFLY FALL
MODERATE AT TIMES AS WE GET TOWARDS THE MID TO LATE EVENING. THE
STEADIER RAIN SHOULD THEN START TO TAPER OFF WEST TO EAST AS WE GO
INTO THE OVERNIGHT PERIOD SUNDAY NIGHT AND THE WARM FRONT LIFTS
NORTH AND EAST OF THE REGION. WE WILL BE IN THE SYSTEM'S WARM SECTOR
AND THE COLD FRONT WILL NOT ARRIVE UNTIL WE GET TOWARDS SUNRISE
MONDAY MORNING. SO THIS MEANS THERE WILL CONTINUE TO AT LEAST BE
SOME SCATTERED SHOWERS AROUND OVERNIGHT UNTIL THE COLD FRONT SWEEPS
THROUGH MONDAY MORNING. WE ARE GENERALLY STILL EXPECTING A QUARTER
TO HALF INCH OF RAIN WITH THE SYSTEM WITH EVEN SOME LOCALLY HIGHER
AMOUNTS UP TO THREE QUARTERS OF AN INCH POSSIBLE. OVERNIGHT LOWS
WILL BE QUITE MILD SUNDAY NIGHT...GENERALLY IN THE 50S EXCEPT SOME
40S OVER THE SOUTHERN POCONOS AND NW NJ.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
THE MAIN FEATURE IN THIS PERIOD WILL BE THE SECONDARY COLD FRONT
ON TUESDAY.
ON MONDAY MORNING, THE FIRST, INITIAL COLD FRONT WILL MOVE OFF
SHORE, AND WITH THAT ANY LINGERING RAIN SHOULD ALSO DEPART THE
REGION. THIS WILL LEAVE A TRANQUIL DAY. DUE TO THE TIMING OF THE
FRONT, AND THE RELATIVELY WEAK TEMPERATURE GRADIENT ACROSS THIS
FRONT, HIGH TEMPERATURES ON MONDAY WILL BE A 5 TO 10 DEGREES
HIGHER THAN TODAY (HIGHS ON MONDAY SHOULD RANGE FROM THE UPPER
50S TO LOWER 70S). HOWEVER, IT WILL LIKELY BE A CASE WHERE HIGH
TEMPERATURES ARE REACHED RELATIVELY EARLY (MID DAY OR EARLY
AFTERNOON) BEFORE THEY START TO DECREASE.
THE NEXT MID LEVEL SHORTWAVE TROUGH WILL APPROACH AND PASS
NORTH OF THE REGION MONDAY NIGHT INTO TUESDAY. AT THE SURFACE A
SECONDARY COLD FRONT WILL SWEEP THROUGH OUR REGION; THE FRONT
SHOULD BE SOUTH AND EAST OF OUR REGION LIKELY BY SUNRISE TUESDAY
MORNING. ALTHOUGH THIS WILL BE THE STRONGER OF THE TWO COLD
FRONTS IN TERMS OF TEMPERATURE GRADIENT, THERE IS LITTLE
OPPORTUNITY FOR MOISTURE ADVECTION BETWEEN THE TWO FRONTS, SO NO
PRECIPITATION IS EXPECTED. HIGH TEMPERATURES ON TUESDAY ARE
EXPECTED TO BE 10 TO 15 DEGREES LOWER THAN MONDAY'S HIGHS,
RANGING FROM THE MID 40S TO NEAR 60. IN ADDITION TO THE COOLER
AIR, DRY AIR ADVECTION IS ALSO EXPECTED IN THE WAKE OF THE
FRONT. CONSEQUENTLY, THIS COULD SET THE STAGE FOR ANOTHER RISK
OF FIRE SPREAD (SEE THE FIRE WEATHER SECTION BELOW).
LONG TERM /WEDNESDAY THROUGH SATURDAY/
MOSTLY TRANQUIL WEATHER IS EXPECTED THROUGH THIS PERIOD. MOST OF
THIS PERIOD WILL BE DOMINATED BY SURFACE HIGH PRESSURE OVER OUR
REGION - ESPECIALLY FOR THE WEEKEND.
THE ONE EXCEPTION IS THAT ANOTHER SURFACE LOW COULD GET CLOSE
ENOUGH TO THE REGION ON THURSDAY FOR A CHANCE FOR PRECIPITATION,
BUT IT IS HIGHLY UNCERTAIN. A FAIRLY STRONG UPPER LEVEL TROUGH
WILL MOVE TOWARDS AND ACROSS THE EAST COAST WITH A WEAKENING
FRONTAL SYSTEM AT THE SURFACE DURING THIS PERIOD. SOME GUIDANCE
DEPICTS THIS TAKING A MORE NORTHERN TRACK (CLOSER TO OUR
REGION), WHILE OTHER MODELS DEPICT THIS LOW GOING WELL SOUTH OF
OUR REGION. IF THE NORTHERN TRACK VERIFIES, THEN ANOTHER ROUND
OF PRECIPITATION WOULD BE POSSIBLE ON THURSDAY. HOWEVER, THE
SOUTHERN TRACK WOULD KEEP OUR REGION DRY.
WHILE SOME GUIDANCE STILL DEPICTS COASTAL LOW DEVELOPMENT
THEREAFTER FOR THE THURSDAY NIGHT INTO FRIDAY TIMEFRAME, IT
DEPICTS IT TOO FAR AWAY FROM OUR REGION TO HAVE ANY IMPACT ON
RAIN CHANCES. RATHER, DRY CONDITIONS SHOULD RETURN LATE IN THE
WEEK INTO NEXT WEEKEND.
AVIATION /07Z SUNDAY THROUGH THURSDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
OVERNIGHT...VFR CONDITIONS. INCREASING HIGH CLOUDS. WINDS REMAINING
LIGHT AND VARIABLE. HIGH CONFIDENCE.
SUNDAY...VFR CONDITIONS CONTINUE, ALTHOUGH CLOUDS WILL INCREASE AND
LOWER THROUGH THE AFTERNOON. WINDS INCREASE OUT OF THE SOUTHWEST 5-
10 KNOTS AFTER SUNRISE, THEN BEGIN TO GUST 15-20 KNOTS LATER IN THE
MORNING INTO THE AFTERNOON. HIGH CONFIDENCE.
SUNDAY NIGHT...CONDITIONS LOWER TO MVFR THROUGH THE EARLY TO MID
EVENING AS RAIN QUICKLY MOVES IN WEST TO EAST AND LIKELY DOWN TO IFR
FOR MOST SITES BY THE OVERNIGHT PERIOD. WINDS INCREASE OUT OF THE
SOUTHWEST 10-15 KNOTS, WITH GUSTS 15-20 KNOTS. HIGH CONFIDENCE.
OUTLOOK...
MONDAY...VFR.
TUESDAY...VFR WITH GUSTY NORTHWEST WINDS UP TO 25 KT.
WEDNESDAY...VFR.
THURSDAY...SUB-VFR POSSIBLE WITH A CHANCE OF RAIN SHOWERS.
MARINE
TRANQUIL EARLY THIS MORNING BUT EXPECT S/SW WINDS TO INCREASE AS WE
GO THROUGH THE DAY SUNDAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR
THE ATLANTIC OCEAN WATERS OFFSHORE OF DELAWARE AND NEW JERSEY
STARTING 1 PM SUNDAY AND CONTINUING THROUGH SUNDAY NIGHT. THE
ADVISORY STARTS AT 6 PM ON DELAWARE BAY. GENERALLY EXPECT SOUTHWEST
WINDS GUSTING UP TO 30 KNOTS WITH EVEN A FEW GUSTS UP TO 35 KNOTS
POSSIBLE SUNDAY NIGHT.
OUTLOOK...
MONDAY...LINGERING SCA CONDITIONS POSSIBLE THROUGH EARLY MONDAY
AFTERNOON WITH WIND GUSTS UP TO 25 KT AND SEAS AROUND 5 FEET.
EXPECT A LULL IN SEAS AND WINDS STARTING MONDAY AFTERNOON.
TUESDAY...THE LULL IN WINDS AND SEAS SHOULD CONTINUE FOR MOST OF
MONDAY NIGHT, BUT NEAR SUNRISE TUESDAY, ANOTHER PERIOD OF SCA
CONDITIONS IS POSSIBLE DUE TO NW WIND GUSTS AROUND 25 KT AND
SEAS AROUND 5 FEET. GIVEN HOW LONG THE LULL IN WINDS AND SEAS IS
EXPECTED TO BE, THIS WILL BE TREATED AS A SEPARATE SCA EVENT
FROM THE SUNDAY NIGHT/MONDAY EVENT.
WEDNESDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD STAY BELOW
SCA CRITERIA.
FIRE WEATHER
EVEN THOUGH PORTIONS OF NORTHERN NEW JERSEY AND NORTHEAST
PENNSYLVANIA MAY HAVE RH VALUES NEAR 35 PERCENT FOR FEW HOURS
AROUND MIDDAY SUNDAY AND WINDS WILL BE GUSTY AROUND 20 MPH,
DEWPOINTS WILL INCREASE THROUGH THE DAY AND RH VALUES WILL
INCREASE IN THE AFTERNOON. THEREFORE, NO FIRE WEATHER RELATED
STATEMENTS ARE EXPECTED FOR SUNDAY AT THIS TIME.
SHOWERS ARE FORECAST TO RESULT IN A WETTING RAIN (0.25-0.50
INCHES CURRENTLY FORECAST) LATER SUNDAY, ESPECIALLY AT NIGHT,
INTO MONDAY MORNING.
THE RELIEF MAY BE SHORT-LIVED THOUGH AS VERY DRY AND BREEZY
CONDITIONS ARE EXPECTED ONCE AGAIN ON TUESDAY. IN THE WAKE OF A
COLD FRONT ON TUESDAY, MINIMUM RH VALUES COULD BE NEAR 30
PERCENT, AND WIND GUSTS OF 25 TO 35 MPH WILL BE POSSIBLE.
CLIMATE
RECORD STRETCH (CONSECUTIVE DAYS) WITHOUT MEASURABLE
PRECIPITATION:
CURRENT
SITE RECORD RECORD DATES THRU 11/9
AC AIRPORT (ACY) 34 DAYS AUG-SEP 1995 38 DAYS
AC MARINA (55N) 39 DAYS AUG-SEP 1995 39 DAYS
GEORGETOWN (GED) 34 DAYS OCT-NOV 2001 43 DAYS
PHILADELPHIA (PHL) 29 DAYS OCT-NOV 1874 42 DAYS
TRENTON (TTN) 38 DAYS APR-MAY 1903 42 DAYS
WILMINGTON (ILG) 34 DAYS JAN-FEB 1909 42 DAYS
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST MONDAY
FOR ANZ430-431.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO NOON EST
MONDAY FOR ANZ450>455.
SYNOPSIS...DESILVA/JOHNSON
NEAR TERM...FITZSIMMONS
SHORT TERM...DESILVA/JOHNSON
LONG TERM...DESILVA/JOHNSON
AVIATION...FITZSIMMONS/JOHNSON
MARINE...FITZSIMMONS/JOHNSON
FIRE WEATHER...WFO PHI
CLIMATE...WFO PHI
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