043
FXUS61 KPHI 021557
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1157 AM EDT Tue Jul 2 2024

.SYNOPSIS...
High pressure builds in today before moving offshore Wednesday.
A more active period begins Thursday with the arrival of a
surface trough, bringing hot and humid conditions along with
chances for showers and storms each day into the weekend. A
frontal boundary may linger through the region into early next
week, with unsettled conditions persisting.

&&

.NEAR TERM /THROUGH TONIGHT/...
Ridge will be building in aloft through today despite a few weak
shortwave passing by thru tonight. With little low-level moisture
remaining (dews in the 50s), even these weak impulses will have
no chance of producing any precip or even much in the way of
cloud cover. This will be aided by the surface high sitting just
to our north this afternoon, shifting to our northeast tonight
but overall remaining in control. A mostly sunny afternoon with
continued low humidity and temperatures staying a little below
normal, but warmer than yesterday. Dewpoints will creep up a
little, so not quite as pleasant, especially given less of a
breeze, but still quite nice by early July standards. Tonight
will overall be similar to last night, with radiational cooling
resulting in 60s in the warmer spots and 50s in the cooler ones.
Mostly clear skies will continue, though with developing
easterly flow, a few models are trying to throw some low clouds
or fog up against the coast. For now will disregard given dry
air mass in place, but something to watch.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The high will continue to progress eastward into Wednesday as
it slips offshore. This will shift winds to be more southerly,
strengthen slightly, and begin to slowly draw more warm and
moist air back into the region. Wednesday looks to remain
pleasant overall though with highs mainly in the mid-upper 80s
and dewpoints in the upper 50s to near 60 degrees.

Things start to change as we head into Independence Day. There
will be a fairly broad upper level trough with an associated
surface low moving through eastern Canada and this will push a
warm front into the region Wednesday night followed by a weak
cold front approaching from the north later on the 4th. This
will bring warmer temperatures for the 4th with the big story
being the noticeable increase in humidity. Expect highs mainly
in the upper 80s to low 90s with dewpoints in the upper 60s to
low 70s. The result will be apparent temperature values maxing
out in the mid to upper 90s.

There will also be more in the way of cloud cover with increasing
chances for scattered showers and thunderstorms by Thursday
afternoon into the evening. While we`re not looking at a total
washout all day rain type of event, the favored timing during
the afternoon and evening will not be ideal. Right now POPs are
generally around 40 to 50 percent. At this point, widespread
severe weather remains unlikely with this setup. however, with
PWATs progged to reach 2.0+ inches, we could end up experiencing
more of a flooding / flash flooding set up. Greatest instability
looks to be mainly south and west of our area, so there will
likely be a lot of mesoscale features at play that remain a bit
unclear at this time. Still a few days out, so this will be
refined as we get closer in time.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The forecast looks to remain on the unsettled side at times
through much of the holiday weekend period. This will be due to
a frontal boundary getting hung up in the area as a series of
impulses move through. The result will be increasingly hot and
humid conditions with chances for scattered showers and
thunderstorms, especially during the afternoon and evening
periods. POPs are a little lower for Friday (generally around 30
to 40 percent) before increasing to around 50 to 60 percent for
Saturday as an approaching cold front and more synoptic
influence aloft will bring a threat for more widespread showers
and thunderstorms. While this is still several days out,
Saturday looks like it could be the more favored day for severe
weather.

Expect highs then mainly in the low to mid 90s (cooler right
near the coast and over the southern Poconos) with dewpoints in
the 70s potentially bringing heat indicies to near 100 to 105
degrees. If this forecast were to hold, heat headlines will end
up being needed. Beyond Saturday it will likely stay quite warm,
but trend less humid with decreasing chances for precip for
Sunday and Monday in the wake of the cold front. Some guidance
suggests the frontal boundary may linger somewhere nearby. This
would support a continuation of the heat and humidity, and
chances for showers and storms currently remain through Monday.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR. Winds gradually shifting from NNE to ESE at 10 kt
or less. However, a sea breeze may develop and affect KACY and
KMIV which could result in a quick shift to SE winds with wind
speeds of 10 to 15 KT. If a sea breeze develops, it would be
most likely to affect the terminals between 18 and 00Z. High
confidence on the overall pattern, moderate confidence on sea
breeze development.

Tonight...VFR. Winds east to southeast around 5 kts. High
confidence.

Outlook...

Wednesday...VFR with no significant weather.

Thursday through Saturday...Sub-VFR conditions possible with
chances (30-60%) for SHRA and TSRA, especially in the afternoon
and evenings each day. The best chances for more widespread
showers and storms looks to be Saturday at this point.

&&

.MARINE...
Winds and seas should remain below Small Craft Advisory Criteria
through tonight. A few models are trying to push some low
clouds/fog up against the coast late tonight, but for now will
disregard, given antecedent air mass is so dry.

Outlook...

Wednesday through Saturday...Conditions are forecast to be
below Small Craft Advisory criteria. Winds gusting up to 20 kts
during the afternoon along with potential for thunderstorms
Thursday and through the weekend.

Rip Currents...

Today...Northeast winds around 10 mph, becoming easterly in the
afternoon. Breaking waves around 1-2 feet. This yields a LOW
risk of the development of dangerous rip currents for both the
Jersey Shore and Delaware Beaches.

Wednesday...Southeast winds around 5-10 mph. Breaking waves
remain around 1-2 feet. Despite more of an onshore flow, with
light conditions expected, have continued with a LOW risk of
dangerous rip currents for both the Jersey Shore and Delaware
Beaches.

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

&&

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

&&

$$

SYNOPSIS...AKL/RCM/Staarmann
NEAR TERM...RCM/po
SHORT TERM...AKL/Fitzsimmons/Staarmann
LONG TERM...AKL/Fitzsimmons/Staarmann
AVIATION...Fitzsimmons/Johnson/MJL/RCM
MARINE...DeSilva/Fitzsimmons/Johnson/RCM