618
FXUS61 KPHI 090536
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1236 AM EST SAT NOV 9 2024
SYNOPSIS
A COLD FRONT CROSSES THE AREA TONIGHT, THEN HIGH PRESSURE WELL
TO THE NORTHWEST BUILDS IN DURING SATURDAY BEFORE SHIFTING
OFFSHORE SUNDAY. A WARM FRONT LIFTS NORTH OF OUR AREA SUNDAY
AFTERNOON, THEN A COLD FRONT CROSSES THE AREA MONDAY. HIGH
PRESSURE BUILDS IN FOR THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TODAY/
COLD FRONT HAS MOVED SOUTH OF THE REGION, AND WINDS ARE
BEGINNING TO DIMINISH A BIT. CAN STILL EXPECT NORTHWEST WINDS 10
TO 15 MPH WITH GUSTS UP TO 20 MPH INTO THIS MORNING, THEN WINDS
DIMINISH MORE TO 5 TO 10 MPH BY LATE SATURDAY MORNING/EARLY
SATURDAY AFTERNOON. COLD AIR ADVECTION IS UNDERWAY, AND LOWS
TONIGHT WILL MAINLY BE IN THE 30S TO LOW 40S.
OTHERWISE, FAIR WEATHER WILL CONTINUE DURING THE NEAR TERM AS
HIGH PRESSURE ACROSS THE UPPER GREAT LAKES REGION GRADUALLY
BUILDS TOWARDS THE MIDDLE ATLANTIC. SKIES WILL REMAIN CLEAR
TONIGHT AND SUNNY ON SATURDAY. IT WILL BE SEASONABLY COLD
TONIGHT AND NOTICEABLY COLDER SATURDAY (COMPARED TO FRIDAY). ON
SATURDAY, INSTEAD OF HIGHS IN THE UPPER 60S AND LOW 70S LIKE
FRIDAY, READINGS WILL FAVOR THE 50S.
SHORT TERM /TONIGHT THROUGH MONDAY/
THE AREA WILL LIE BENEATH AN UPPER LEVEL RIDGE ON SATURDAY
NIGHT WITH THE RIDGE AXIS SLIDING OFFSHORE ON SUNDAY. AS THIS
OCCURS, AN UPPER LEVEL TROUGH WILL LIFT ACROSS THE GREAT LAKES
AND OVER THE NORTHEAST US ON SUNDAY NIGHT INTO MONDAY. AT THE
SURFACE, HIGH PRESSURE WILL LIE OVERHEAD ON SATURDAY NIGHT
BEFORE SHIFTING OFFSHORE ON SUNDAY. A WEAK WARM FRONT WILL LIFT
NORTH OF THE AREA ON SUNDAY WITH A COLD FRONTAL PASSAGE OCCURING
ON MONDAY.
WITH THIS BEING SAID, ANOTHER DRY AND SEASONABLY COOL NIGHT IS
IN STORE FOR SATURDAY NIGHT. THANKS TO LIGHT WINDS AND CLEAR
SKIES, AN EFFICIENT RADIATIONAL COOLING NIGHT LOOKS TO OCCUR.
HOWEVER, THE TRANQUIL WEATHER WILL BE SHORT-LIVED AS SKIES
BECOME MORE CLOUD- FILLED DURING THE DAY ON SUNDAY AS OUR NEXT
WEATHER SYSTEM APPROACHES. LOW PRESSURE WILL BE TRACKING ACROSS
THE NORTHERN GREAT LAKES REGION ON SUNDAY AND ACROSS SOUTHERN
ONTARIO/QUEBEC ON SUNDAY NIGHT AND MONDAY. ASSOCIATED WITH THIS
LOW WILL BE A TRAILING COLD FRONT WHICH IS EXPECTED TO CROSS
THROUGH THE REGION ON MONDAY. BELIEVE IT OR NOT, PERIODS OF
LIGHT RAIN CERTAINLY LOOK PLAUSIBLE AS SOME MOISTURE ASSOCIATED
WITH HURRICANE RAFAEL OVER THE GULF OF MEXICO WILL BE DRAWN
NORTHWARD INTO THE MID-ATLANTIC REGION. THIS WILL BRING SOME
BENEFICIAL RAINFALL TO THE REGION BEGINNING LATE SUNDAY INTO
SUNDAY NIGHT WITH POPS AROUND 90% IN MOST AREAS. AS THE COLD
FRONT CROSSES THROUGH THE REGION ON MONDAY, RAIN IS EXPECTED TO
END FROM WEST TO EAST BY MONDAY MORNING. A FEW LINGERING SHOWERS
MAY HANG UP ALONG THE COAST, BUT OVERALL SHOULD LEAD TO A DRY
DAY BY MONDAY AFTERNOON. IN TERMS OF TOTAL RAINFALL, WE ARE
EXPECTING ROUGHLY 0.25-0.50 INCHES OF RAIN AREAWIDE. ALTHOUGH,
THIS CERTAINLY WILL NOT BE ENOUGH TO BREAK THE ONGOING DROUGHT
CONDITIONS, IT WILL DEFINITELY BE APPRECIABLE CONSIDERING HOW
DRY IT HAS BEEN OVER THE LAST 2 MONTHS.
IN TERMS OF TEMPERATURES FOR THE PERIOD, WE ARE LOOKING AT
HIGHS IN THE UPPER 50S TO MID 60S ON SUNDAY WITH MID 60S TO LOW
70S ON MONDAY. LOWS WILL MAINLY BE IN THE UPPER 20S TO MID 30S
ON SATURDAY NIGHT WITH A MUCH MILDER NIGHT ON SUNDAY NIGHT
EXPECTED WITH LOWS ONLY IN THE UPPER 40S TO MID 50S.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
THE LONG TERM FORECAST REMAINS LARGELY UNCHANGED HOWEVER, THERE
REMAINS SOME UNCERTAINTY WITH WHAT MAY OCCUR LATE IN THE WEEK.
CYCLONIC FLOW IS FORECAST TO REMAIN IN PLACE TUESDAY BEFORE
UPPER- LEVEL RIDGING ARRIVES ON WEDNESDAY. THE NEXT UPPER-LEVEL
TROUGH IS THEN PROGGED TO APPROACH LATE WEDNESDAY INTO THURSDAY,
WHILE BECOMING NEGATIVELY TILTED AND/OR CUTTING OFF BY FRIDAY.
AT THE SURFACE, A SECONDARY COLD FRONT WILL ARRIVE ON TUESDAY
AHEAD OF HIGH PRESSURE LATER TUESDAY INTO WEDNESDAY. A COLD
FRONT THEN ARRIVES WITH POSSIBLE COAST LOW DEVELOPMENT LATER
THURSDAY INTO FRIDAY.
SO FOR RIGHT NOW, EXPECT DRY AND MOSTLY SEASONABLE CONDITIONS
TO OCCUR MONDAY NIGHT THROUGH WEDNESDAY. BY WEDNESDAY NIGHT AND
THROUGH THE END OF THE WEEK, WE'LL NEED TO MONITOR HOW THE UPPER
LEVEL PATTERN EVOLVES OVER THE NEXT SEVERAL DAYS AS THIS PLAYS
A BIG FACTOR ON WHAT WILL OCCUR LATER IN THE WEEK. ALL MAJOR
GLOBAL GUIDANCE SUGGEST THAT THERE WILL POSSIBLY BE SOME SORT OF
COASTAL LOW DEVELOPING ALONG THE MID-ATLANTIC COAST. THE GFS IS
MOST AGGRESSIVE WITH THIS SCENARIO, DEVELOPING A STRONG COASTAL
LOW MOVING UP INTO NEW ENGLAND. THE ECMWF AND CMC ARE MUCH
WEAKER WITH THIS SCENARIO, BUT BOTH DO INCLUDE SOME SORT OF
CYCLOGENESIS OFF THE MID-ATLANTIC. IT IS WORTH MONITORING
NONETHELESS, AS THIS WILL LIKELY BRING ANOTHER PERIOD OF RAINY
WEATHER TO THE AREA LATE NEXT WEEK.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TONIGHT...VFR/SKC. NW WINDS 10 TO 15 KT WITH GUSTS UP
TO 20 KT. HIGH CONFIDENCE.
SATURDAY...VFR/SKC. NW WINDS 10 TO 15 KT WITH GUSTS UP TO 20
KT, BECOMING N 5 TO 10 KT IN THE AFTERNOON. HIGH CONFIDENCE.
OUTLOOK...
SATURDAY NIGHT...VFR. NO SIGNIFICANT WEATHER EXPECTED.
SUNDAY THROUGH SUNDAY NIGHT...VFR FOR MOST OF SUNDAY, WITH SUB-
VFR LIKELY ON SUNDAY NIGHT. PERIODS OF LIGHT RAIN LIKELY.
MONDAY THROUGH WEDNESDAY...VFR. NO SIGNIFICANT WEATHER
EXPECTED.
MARINE
A SCA FLAG TONIGHT AS COLD AIR ADVECTION AND A DECENT PRESSURE
GRADIENT AHEAD OF THE BUILDING HIGH ACROSS THE WATERS. NORTHWEST
WINDS WITH GUSTS OF 25 TO 30 KNOTS ARE EXPECTED OVERNIGHT WHILE
SEAS BUILD TO 4 TO 5 FT ON THE OCEAN. THE SEAS ACROSS DELAWARE
BAY WILL BECOME CHOPPY OVERNIGHT. FAIR WEATHER. WINDS AND SEAS
DECREASE SATURDAY, SO THE SCA FLAG WILL BE DOWN FOR THE DAY.
WINDS WILL BE MOSTLY FROM THE NORTH AT 10 TO 15 KTS.
OUTLOOK...
SATURDAY NIGHT...NO MARINE HEADLINES EXPECTED.
SUNDAY THROUGH MONDAY...A PERIOD OF SCA CONDITIONS IS LIKELY
BEGINNING LATE SUNDAY AFTERNOON INTO MONDAY MORNING WITH GUSTS
UP TO 25-30 KTS AND SEAS AROUND 4-5 FEET.
MONDAY NIGHT THROUGH WEDNESDAY...NO MARINE HEADLINES EXPECTED.
FIRE WEATHER
VERY DRY CONDITIONS CONTINUE, BUT RHS HAVE COME UP ABOVE RED
FLAG CRITERIA. WINDS ARE KICKING UP WITH THE PASSING COLD FRONT
BUT SHOULD DIMINISH AGAIN OVERNIGHT.
FOR SATURDAY, A VERY DRY AIR MASS WILL BE IN PLACE WITH DEW
POINTS DOWN INTO THE UPPER TEENS TO LOWER 20S. DAYTIME MINIMUM
RELATIVE HUMIDITY VALUES ARE FORECAST TO BE IN THE 20-30 PERCENT
RANGE. NORTHERLY WINDS 10-15 MPH SHOULD DIMINISH SOME DURING
THE AFTERNOON. ALTHOUGH THE WINDS ARE LIGHTER COMPARED TO
FRIDAY, THE CONDITIONS CONTINUE TO BE VERY DRY AND THUS AN
ELEVATED RISK FOR FIRE SPREAD REMAINS. AN SPS WILL LIKELY BE
ISSUED THIS EVENING AFTER THE RED FLAG WARNING COMES DOWN.
SHOWERS ARE FORECAST TO RESULT IN A WETTING RAIN (0.25-0.50
INCHES CURRENTLY FORECAST) LATER SUNDAY, ESPECIALLY AT NIGHT,
INTO MONDAY MORNING.
CONTINUE TO FOLLOW BURN RESTRICTIONS AND CHECK WITH YOUR STATE
AND LOCAL FIRE OFFICIALS FOR MORE INFORMATION.
CLIMATE
RECORD STRETCH (CONSECUTIVE DAYS) WITHOUT MEASURABLE
PRECIPITATION:
CURRENT
SITE RECORD RECORD DATES THRU 11/7
AC AIRPORT (ACY) 34 DAYS AUG-SEP 1995 36 DAYS
AC MARINA (55N) 39 DAYS AUG-SEP 1995 37 DAYS
GEORGETOWN (GED) 34 DAYS OCT-NOV 2001 41 DAYS
PHILADELPHIA (PHL) 29 DAYS OCT-NOV 1874 40 DAYS
TRENTON (TTN) 38 DAYS APR-MAY 1903 40 DAYS
WILMINGTON (ILG) 34 DAYS JAN-FEB 1909 40 DAYS
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ430-
431.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
ANZ450>455.
SYNOPSIS...GORSE/OHARA
NEAR TERM...MPS/OHARA
SHORT TERM...DESILVA/GORSE
LONG TERM...DESILVA/GORSE
AVIATION...DESILVA/GORSE/OHARA
MARINE...DESILVA/GORSE/OHARA
FIRE WEATHER...
CLIMATE...
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