168
FXUS61 KPHI 020519
AFDPHI

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

.SYNOPSIS...
High pressure builds in through today before moving offshore
Wednesday. A more active period resumes Thursday with the
arrival of a surface trough but a cold front may not push
through the region until towards the end of the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Ridge will be building in aloft through today despite a weak
shortwave passing early this morning and another passing later
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 northwest early
this morning, shifting to our northeast tonight but overall
remaining in control. A pleasant morning for early July with
lows in the 50s to low 60s will give way to a mostly sunny day
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 early this morning, 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/...
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 dew points in the upper 50s to near 60.

Things start to change as we head into the holiday. 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 increase in humidity. Expect highs mainly in the upper 80s
to low 90s with dew points in the upper 60s to low 70s. The
result will be apparent temperature values maxing out in the mid
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 doesn`t look to be huge threat but
with PWATs progged to reach 2.0+ inches it could end up being
more of a flooding / flash flooding set up. Again, still a few
days out so this will be refined as we get closer in time.

&&

.LONG TERM /THURSDAY NIGHT 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 continuing very warm
to 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 percent for
Saturday as an approaching cold front 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 dew points in the 70s potentially
bringing heat indicies over 100. 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.

&&

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12Z this morning...VFR. Winds north around 5-10 knots,
becoming light and variable at some TAF sites (especially KABE,
KMIV, and KRDG). High confidence.

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 (30-50%) 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.

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
SHORT TERM...AKL/Fitzsimmons
LONG TERM...AKL/Fitzsimmons
AVIATION...Fitzsimmons/Johnson/MJL/RCM
MARINE...DeSilva/Fitzsimmons/Johnson/RCM