134
FXUS61 KPHI 202054
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
454 PM EDT Sat Jul 20 2024

.SYNOPSIS...
Weak high pressure is nearby today as a front remains stalled to our
south. A weak system slides by to our north tonight, then a front
settles into our area Sunday night before stalling in our vicinity
through early next week. This front may dissipate Wednesday then a
cold front should arrive later Thursday or Friday.

&&

.NEAR TERM /THROUGH SUNDAY/...
A little bit of an active and unsettled afternoon ahead as two
systems clip our region. Not expecting much in terms of severe or
impactful weather however. A shortwave trough incoming from the west
will be responsible for sparking a few showers/thunderstorms in the
Lehigh Valley/northern New Jersey/southern Poconos. Should be more
of the garden variety thunderstorms as cloud cover has limited
instability from increasing and shear is rather meager. To the
south, a stalled boundary will slowly lift northward, with an area
of low pressure moving along the boundary and out to sea, just to
the south and east of our area. Some showers will sneak in through
the evening hours for South Jersey and southern Delmarva as the low
slides by. Both features should be clear of the region by daybreak
Sunday. The Philly metro will be caught in the middle of these two
systems, and most around the city will stay dry.

As mentioned previously, showers/a few thunderstorms will continue
into the night, though rain chances are only around 20-40% for the
northern and southern areas. Outside of any rain, it will be mostly
cloudy/overcast, with temperatures falling into the mid to upper
60s.

Should be a quiet Sunday as an upper level low well to the north
moves out towards the North Atlantic. A weak cold front will
approach from the northwest, but not expecting any precipitation as
it enters our area late tomorrow. Temperatures will be right around
normal for mid-summer, with highs in the mid to upper 80s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
There may be a few scattered showers across the southernmost
parts of the region Sunday night, but overall most areas will be
dry Sunday night as the weak upper and surface ridge weaken.
It`ll remain humid and seasonably mild with low temperatures in
the upper 60s/low 70s. Can`t rule out some rural fog overnight.

As we start the week, there are greater chances for showers and
tstms both Mon/Tue as the front that has been the the south of
the area this weekend starts to track northward. Upper energy
arriving from the Midwest will ignite some showers/tstms as it
moves by. We have high chance and low likely pops for much of
the time and with the high PW across the area. Downpours and
some localized flooding can`t be ruled out. High temperatures
will be near normal Mon/Tue with upper 70s/low 80s N/W and
mid/upper 80s S/E.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The synoptic scale Bermuda High at the surface and aloft will
stretch back across the Middle Atlantic area early/mid next week.
This will promote an continuing increase in moisture for the area
with normal or slightly above normal temps much of the time. The
broad SW flow aloft will keep upper disturbances crossing through
atop of the lower level heat and humidity. Consequently, chances
for showers and tstms exist for the entire period from Mon night
into Wednesday. This highest pops for the period (Wednesday)
occur as a stronger disturbance and surface low move across the
Great Lakes up into southern Canada. A front attached will cross
the area. We`ll have Likely pops in most areas which will continue
into the evening/overnight for the SE parts of the area. There
are some differences with the models, so we do expect some
timing chances as we get closer to the event.

Later next week, the upper trough over the Great Lakes continues to
push east towards New England. It`s influence across our region will
be low/medium at best with some added synoptic scale lift and higher
chances for showers and tstms. We`ll carry these higher pops (high
chance/low likely) for Thursday and then decrease to pops back to
lower chance for Friday. Drier air will arrive behind a front which
will cross the area Late Thursday night. The front (as the one that
crossed our region late last week) will not chance temperatures too
much, so readings will remain near normal late next week.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas...

Rest of Today...Prevailing VFR. High and mid level clouds around,
but no impact to terminals. Slight chance (15-25%) of a shower or
thunderstorm, most likely at KABE and have included a VCTS there,
though the bulk of the showers/thunderstorms should remain off to
the north from there. Southerly winds around 10 kt. Moderate
confidence.

Tonight...Prevailing VFR conditions expected to continue but chances
for showers increase, mainly at KACY/KMIV. However, most recent
guidance has trended lower with rain chances, and if a shower did
make it to the terminal, still expecting VFR to prevail.
Slight chance (15-20%) of a shower within the I-95 corridor this
evening, but given that any showers should be light and rain chances
are only for a short period, have elected to not have any rain
mentioned for the I-95 terminals. Winds become light once again, but
may favor a south-southwest direction, particularly for the I-95
terminals. Moderate confidence.

Sunday...VFR. South/southwest winds around 5-10 kt at the South
Jersey terminals, with west/northwest winds elsewhere around 5-10 kt.
High confidence in prevailing VFR, moderate confidence in wind
direction.

Outlook...

Sun night... Mostly VFR. Patchy rural fog possible.

Monday thru Thursday... VFR except with scattered showers/tstms
  which will bring lower CIGS/VSBYS at times. Timing of the
  lower conditions is mostly afternoon/early evening.

&&

.MARINE...
No marine headlines expected on the waters. Winds around 5-10 kt with
2 to 3 foot seas. Some showers possible, mainly south of Little Egg
Inlet.

Outlook...
More typical summertime weather with limited winds and seas
(sub-SCA) and scattered showers/tstms. Storms favoring the late
afternoon and evening hours. Higher winds and seas with tstms.

Rip Currents...

For Sunday...South-southeast winds around 5-10 mph with breaking
waves around 1-2 feet and a 6 to 7 second period. This yields a
LOW risk for the development of dangerous rip currents for both
the Jersey Shore and Delaware Beaches.

For Monday...South-southeast winds around 10 mph with breaking
waves around 1-3 feet and a 9 to 10 second period. Full Moon
phase occurs on Monday as well. With onshore flow becoming a
bit more perpendicular for southeasterly facing beaches, a
longer period and a full moon, have opted to go with a MODERATE
risk for rip currents for Atlantic/Cape May Counties. For
Ocean, Monmouth and Delaware Beaches, continued with a LOW risk
for dangerous rip currents.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...Gorse
NEAR TERM...Hoeflich
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...Hoeflich/OHara
MARINE...DeSilva/Hoeflich/OHara