066
FXUS61 KPHI 130300
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1000 PM EST TUE NOV 12 2024
SYNOPSIS
HIGH PRESSURE REMAINS IN CONTROL THROUGH THURSDAY. A WEAK LOW
WILL APPROACH THE REGION ON THURSDAY NIGHT WITH A COASTAL LOW
DEVELOPING TO OUR SOUTH WHICH WILL MOVE OUT TO SEA ON FRIDAY.
HIGH PRESSURE RETURNS FOR THE WEEKEND AHEAD OF A COLD FRONT THAT
APPROACHES THE REGION EARLY NEXT WEEK.
NEAR TERM /THROUGH WEDNESDAY/
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH OVERNIGHT
AND INTO WEDNESDAY. WINDS ARE GRADUALLY DIMINISHING. COLD AIR
WILL FILTER IN WITH LOWS EXPECTED TO DROP IN TO THE MID 20S TO
LOW 30S, PLACING MUCH OF THE REGION BELOW FREEZING WITH THE
EXCEPTION OF THE IMMEDIATE COAST STAYING IN THE MID-30S.
ANOTHER DRY AND COOL DAY WEDNESDAY WITH SUNNY SKIES AND
AFTERNOON HIGHS ONLY REACHING THE UPPER 40S TO LOW 50S. A VERY
DRY AIRMASS WILL BE IN PLACE AT THIS POINT WITH MINIMUM RH
VALUES DROPPING TO 20- 30% ACROSS MOST LOCATIONS, BUT WINDS ARE
EXPECTED TO BE MUCH LOWER WITH NORTHERLY WINDS GUSTING TO AROUND
10-15 MPH. GIVEN THE DRY AIRMASS, FIRE WEATHER RISK WILL REMAIN
ELEVATED WEDNESDAY. SEE FIRE WEATHER SECTION BELOW.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/
THE WEDNESDAY NIGHT AND THURSDAY PERIOD WILL FEATURE TRANQUIL
AND SEASONABLY COOL WEATHER OVERALL, AS STRONG HIGH PRESSURE
SLOWLY SHIFTS EAST ACROSS SOUTHERN CANADA. CLOUDS WILL GRADUALLY
INCREASE THROUGH THIS TIME AS THE NEXT WEATHER SYSTEM
APPROACHES FROM THE MIDWEST. LOWS ON WEDNESDAY NIGHT WILL MAINLY
BE IN THE MID 20S TO MID 30S WITH HIGHS ON THURSDAY IN THE 40S
AND 50S.
ATTENTION THEN TURNS TO THE THURSDAY NIGHT INTO FRIDAY PERIOD
AS A DECAYING TROUGH AND WEAKENING SURFACE LOW MOVES TOWARD THE
AREA. THE SURFACE LOW IS FORECAST TO TRACK INTO THE EASTERN
GREAT LAKES BEFORE TRANSLATING ITS ENERGY TO A DEVELOPING
SECONDARY COASTAL LOW OFF THE COAST OFF THE CAROLINAS. THIS LOW
WILL THEN MOVE OUT TO SEA WITHOUT POSING MUCH OF A THREAT TO THE
MID-ATLANTIC. SO AS THIS INITIAL LOW APPROACHES, RAIN SHOWERS
ARE EXPECTED TO MOVE INTO OUR AREA, ESPECIALLY SOUTH AND WEST OF
PHILADELPHIA (WHERE POPS ARE UP TO 40- 60%). TO THE NORTH AND
EAST OF PHILADELPHIA, THE STRONG HIGH PRESSURE OVER CANADA
SHOULD CAUSE A SHARP MOISTURE GRADIENT, SO THESE LOCATIONS MAY
SEE A FEW ISOLATED SHOWERS TO NOTHING AT ALL. IN TERMS OF QPF,
GENERALLY LOOKING AT 0.10-0.25" SOUTH AND WEST OF PHILLY, WITH
LESS THAN 0.10" NORTH AND EAST OF PHILLY. SURPRISINGLY, THIS
SET-UP DOES APPEAR TO BE A COLD AIR DAMMING SET-UP, MAINLY IN
THE POCONO REGION, SO WOULDN'T BE SURPRISED IF THERE IS A SHORT
PERIOD OF FROZEN PRECIP ON THURSDAY NIGHT IF ANY PRECIP IS TO
MAKE IT INTO THESE AREAS. LOWS WILL MAINLY BE IN THE 30S/40S.
ANY SHOWERS WILL THEN TAPER OFF FROM NORTH TO SOUTH EARLY ON
FRIDAY WITH CLEARING SKIES BY THE AFTERNOON AS HIGH PRESSURE
BUILDS BACK IN FROM THE WEST. HIGHS WILL REMAIN A FEW DEGREES
BELOW NORMAL MAINLY IN THE UPPER 40S TO MID 50S.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
HEADING INTO NEXT WEEKEND, UPPER LEVEL RIDGING IS FORECAST TO
BUILD AS AN EXPANSIVE AREA OF HIGH PRESSURE APPROACHES FROM THE
WEST. THIS WILL RESULT IN A DRY WEEKEND WITH TEMPERATURES
RETURNING TO ABOVE NORMAL STANDARDS. IT MAY BE BREEZY AT TIMES
OVER THE WEEKEND HOWEVER AND WITH DRY NORTHWESTERLY FLOW, THIS
COULD SPARK AN ADDITIONAL ROUND FOR SOME FIRE WEATHER
CONCERNS...HOWEVER ITS TOO FAR IN ADVANCE TO NARROW DOWN
SPECIFICS.
BY EARLY NEXT WEEK, A SHORTWAVE TROUGH WILL APPROACH THE REGION
WITH A SURFACE COLD FRONT. CURRENT TIMING AT THIS POINT APPEARS
TO BE ON MONDAY WHERE A FEW RAIN SHOWERS MAY BE POSSIBLE WITH
THE FRONT. HIGH PRESSURE THEN RETURNS FOR TUESDAY AS
TEMPERATURES STILL REMAIN A FEW DEGREES ABOVE NORMAL.
AVIATION /03Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
OVERNIGHT...VFR CONDITIONS EXPECTED. NORTHERLY WIND SPEEDS
DIMINISHING SLOWLY BUT REMAINING 5-10 KTS THRU THE NIGHT MOST
TERMINALS.
WEDNESDAY...VFR. NORTH TO NORTH-NORTHEAST WINDS AROUND 5-10 KT.
OUTLOOK...
WEDNESDAY NIGHT...VFR WITH INCREASING CLOUDS. NO SIGNIFICANT
WEATHER EXPECTED.
THURSDAY THROUGH THURSDAY NIGHT...MAINLY VFR. SUB-VFR
CONDITIONS POSSIBLE ON THURSDAY NIGHT WITH A CHANCE OF RAIN
SHOWERS.
FRIDAY THROUGH SATURDAY...VFR. NO SIGNIFICANT WEATHER EXPECTED.
MARINE
SMALL CRAFT ADVISORY IN EFFECT FOR THE ENTIRE MARINE AREA. NNW
WINDS REMAIN GUSTY AROUND 30 KT THIS EVENING WITH SEAS 4-7
FEET, EXPECTING WINDS TO GRADUALLY DIMINISH OVERNIGHT. UPPER
AND LOWER DELAWARE BAY WILL SEE WINDS FALL BELOW ADVISORY
CRITERIA OVERNIGHT WITH THE REMAINING COASTAL MARINE ZONES
SEEING LINGERING SEAS 3-5 FEET THROUGH THE AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT THROUGH FRIDAY...SMALL CRAFT ADVISORY
CONDITIONS ON THE ATLANTIC OCEAN COASTAL WATERS ARE POSSIBLE
MAINLY DUE TO SEAS HOVERING AROUND 5 FEET.
FRIDAY NIGHT THROUGH SATURDAY...SMALL CRAFT ADVISORY CONDITIONS
LIKELY DUE TO WINDS AROUND 25-30 KT AND SEAS AROUND 5 FEET.
FIRE WEATHER
FOR WEDNESDAY, DRY CONDITIONS ARE EXPECTED TO CONTINUE. WINDS
WILL GENERALLY BE NEAR 5-10 MPH WITH A FEW GUSTS UP TO 15 MPH,
MUCH LOWER THAN THE DAY BEFORE. A VERY DRY AIRMASS WILL BE IN
PLACE HOWEVER WITH MINIMUM RH VALUES WILL FALLING INTO THE
20-30% RANGE.
RH VALUES DO RECOVER THURSDAY WITH A CHANCE OF SHOWERS IN THE
AFTERNOON AND EVENING. BEST CHANCE FOR RAINFALL WILL BE SOUTH
AND WEST OF THE PHILADELPHIA METRO WITH MINIMAL RAINFALL NORTH
AND EAST.
LOOKING FARTHER AHEAD, RH VALUES REMAIN IN THE 30-40% RANGE FOR
FRIDAY AND INTO THE WEEKEND ALONG WITH SOME BREEZY CONDITIONS.
TIDES/COASTAL FLOODING
CONFIDENCE HAS INCREASED THAT A COMBINATION OF PERSISTENT SHORE
PARALLEL WINDS AND INCREASING ASTRONOMICAL TIDES WITH A FULL
MOON ON FRIDAY LOOK TO LEAD TO COASTAL FLOODING FOR THE BACK
HALF OF THE WEEK. WIDESPREAD MINOR TIDAL FLOODING IS EXPECTED
ALONG THE ATLANTIC OCEAN COASTS OF NEW JERSEY AND DELAWARE AND
THE ASSOCIATED BACKBAYS AS WELL AS THE CENTRAL DELAWARE COAST OF
THE DELAWARE BAY BEGINNING WITH THE THURSDAY MORNING HIGH TIDE.
ADDITIONALLY, POTENTIAL REMAINS FOR MODERATE COASTAL FLOODING
WITHIN THIS AREA. AS A RESULT, A COASTAL FLOOD WATCH HAS BEEN
ISSUED BEGINNING EARLY THURSDAY MORNING AND CONTINUING THROUGH
MIDDAY FRIDAY.
LEADING UP TO THE MORE POTENTIALLY IMPACTFUL HIGH TIDES, TIDES
WILL BEGIN TO PILE AS THE SHORE PARALLEL FLOW LIMITS THE AMOUNT
OF WATER THAT CAN DRAIN AWAY FROM THE COAST AT LOW TIDE. AS A
RESULT, MINOR TIDAL FLOODING IS EXPECTED TO OCCUR BEGINNING WITH
THE EARLY WEDNESDAY MORNING HIGH TIDE. A COASTAL FLOOD ADVISORY
HAS BEEN ISSUED FOR CAPE MAY, NJ AND SUSSEX, DE COUNTIES
BEGINNING AT 4 AM WEDNESDAY MORNING WHERE MINOR TIDAL FLOODING
IS EXPECTED TO BE MOST WIDESPREAD. SPOTTY MINOR TIDAL FLOODING
IS FORECAST WITH THE EARLY WEDNESDAY MORNING HIGH TIDE FOR THE
REMAINDER OF THE AREA WITHIN THE COASTAL FLOOD WATCH.
BY THURSDAY AND INTO FRIDAY, TIDAL PILING INTO THE LOWER DELAWARE
BAY LOOKS TO RESULT IN MINOR TIDAL FLOODING OCCURING FURTHER
NORTH, ALONG THE SHORES OF THE UPPER DELAWARE BAY AS WELL AS THE
TIDAL DELAWARE RIVER.
COASTAL FLOODING IS NOT EXPECTED TO OCCUR ALONG THE CHESAPEAKE
BAY IN THE EASTERN SHORE OF MARYLAND.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD WATCH FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY
MORNING FOR NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY FROM 4 AM TO 10 AM EST WEDNESDAY FOR
NJZ023-024.
DE...COASTAL FLOOD WATCH FROM LATE WEDNESDAY NIGHT THROUGH FRIDAY
MORNING FOR DEZ002>004.
COASTAL FLOOD ADVISORY FROM 4 AM TO 10 AM EST WEDNESDAY FOR
DEZ003-004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 1 PM EST WEDNESDAY FOR ANZ450.
SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ451>455.
TO
SYNOPSIS...DESILVA/HOEFLICH/RCM
NEAR TERM...MJL/RCM
SHORT TERM...DESILVA
LONG TERM...DESILVA/HOEFLICH
AVIATION...DESILVA/MJL/RCM
MARINE...DESILVA/MJL/RCM
FIRE WEATHER...MJL
TIDES/COASTAL FLOODING...AKL
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