739
FXUS61 KPHI 180646
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
246 AM EDT Thu Jul 18 2024

.SYNOPSIS...
A strong cold front will cross the Middle Atlantic region
early this morning. It will be followed by high pressure for
the end of the week and into the weekend. Another upper system
and surface front will arrive by early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
245 AM...As of early this morning, low pressure was located in
northeastern Canada near Labrador with its trailing cold front
extending southwest across the mid Atlantic region near the I-95
corridor. The storms from earlier have weakened and moved off
the coast but there is still lingering cloud cover and isolated
showers around due to the front. As we go through the remainder
of the overnight hours the front will continue to move off to
the south and east but only very slowly before eventually
getting hung up near or just off the coast by Thursday morning.
Lows should range from the low to mid 70s for areas near and
south/east of the urban corridor where it will also still be
pretty humid with dew points also in the low 70s. As result,
expect some patchy fog around. Farther to the north and west
behind the front it will get down into the 65 to 70 range from
the Leigh Valley into the southern Poconos and NW NJ.

For Thursday, the aformentioned front should linger just off
the NJ coast extending south/west into southern Delmarva. This
will keep a fair amount of cloud cover around for southern and
coastal NJ as well as Delmarva where there could be some
isolated to scattered showers or storms around during the day.
Farther north, along and north of the I-95 corridor, expect the
day to be dry with lowering humidity due to NW winds and just
some lingering mid and high cloud cover around. Generally expect
highs in the mid/upper 80s except a bit cooler near the coast
and over the southern Poconos. As mentioned, dew points will
also be falling to more comfortable values (into the 60s) for
most places but will still be in the low 70s over southern
Delmarva into parts of coastal and southern NJ closer to the
front.

The front will continue slowly sliding southeastward away from
the area Thursday night. A few showers or thunderstorms may
linger in the evening across southern Delaware but it should
clear out after midnight. Lows will be in the considerably more
comfortable 60s for most of the area.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Friday looks like the most pleasant day of the forecast as
Canadian high pressure briefly builds southward into the area.
Dew points will be down into the upper 50s and lower 60s with
highs only in the mid to upper 80s with mostly sunny skies and
light winds.

High pressure starts to push eastward with a lee-side trough
developing on Saturday. With winds turning back to the south,
dew points will start to creep back up. The increased moisture
plus lee side trough combined with a weak upper disturbance
working in from the southwest may be enough to bring some
scattered showers and isolated thunderstorms by afternoon,
especially west and southwest of Philly. Further north and east,
dry conditions should prevail. While dew points will be back
solidly into the 60s, highs should remain mostly in the upper
80s, so still considerably more comfortable than recent days,
but not quite as nice as Friday.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The stalled front to our south will gradually creep back
northward as we head into the middle of next week. Combined with
passing upper disturbances, this should result in a general
turn towards cloudier, more showery weather, with lower temps by
mid week.

At first however, Sunday should be similar to Saturday, with
some spotty convection possible mainly west and southwest of
Philly. Dew points keep creeping up, but temps remain in the
upper 80s overall.

By Monday the increased moisture is more apparent, as dews
start to approach 70 and the front starts to push back north.
This should result in a slightly better chance of convection,
but again, not huge. Still mainly upper 80s for highs.

Tuesday and Wednesday are when conditions turn wetter, with the
front pushing back into the area with clouds and scattered
showers/t- storms becoming common. This will cause cooler temps
as well, with highs down into the mid 80s, but dew points rising
into the low-mid 70s. Will need to monitor for any locally
heavy rain risks given high moisture and slow moving front in
the vicinity, but overall this looks like a beneficial change in
the weather.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Rest of Overnight...Showers/storms have ended but expect some
patchy fog and areas of low stratus that could affect TAF sites
with sub VFR conditions. Best chances for this will be at ACY,
MIV, ABE, and RDG. Winds light and variable but trending towards
NW by morning. Moderate confidence.

Thursday...Some lingering sub VFR cigs early in the morning with
a few lingering showers possible at MIV and ACY. Some afternoon
showers and storms possible for ACY. Otherwise VFR. NW winds
around 5 to 10 knots. Moderate confidence.

Thursday night...VFR. Northwest winds around 5 knots in the
evening veering to north/northeast overnight around 5 knots.

Outlook...

Friday thru Friday night...VFR with no significant weather.

Saturday through Monday...mostly VFR with a slight chance of
showers and thunderstorms, mainly in the afternoon and evening
hours.

&&

.MARINE...
Small Craft Advisory in effect until 8 AM Thursday morning for
ocean zones mainly due to seas still lingering around 5 feet.
Seas should drop back down to around 3-4 feet for the rest of
the day Thursday continuing through Thursday night. There could
also be some lingering scattered showers and storms over the
waters through Thursday.

Outlook...

Friday through Monday...Conditions will generally be below
Small Craft Advisory criteria. Wind gusts of 15 kt or less with
wave heights of 4 feet or less. Slight chance showers and
thunderstorms, mainly in the afternoon and evening hours.

Rip currents...

For Thursday, winds will turn more offshore out of the west to
northwest and decrease to around 10 mph. Wave heights will
mainly be around 1-2 feet in Delaware and 2-3 feet in New
Jersey with a 7-8 second period. As the winds should be weaker
and directed offshore across the region, the risk for the
development of dangerous and life threatening rip currents is
forecast to be LOW at the DE beaches and MODERATE at the NJ
shore on Thursday.

For Friday, winds will become northeasterly but remain around
10 mph. Wave heights will mainly remain around 1-2 feet in
Delaware and 2-3 feet in New Jersey with a 7-8 second period.
Therefore, the risk for the development of dangerous and life
threatening rip currents is forecast to be LOW at the DE beaches
and MODERATE at the NJ shore on Friday.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
     ANZ450>455.

&&

$$

SYNOPSIS...RCM
NEAR TERM...Fitzsimmons/MJL
SHORT TERM...RCM
LONG TERM...RCM
AVIATION...Fitzsimmons/MJL/RCM
MARINE...Fitzsimmons/MJL/RCM