157
FXUS61 KPHI 011950
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
Issued by National Weather Service Baltimore MD/Washington DC
350 PM EDT Wed May 1 2024

.SYNOPSIS...
A warm front lifts through tonight. A cold front looks to cross
through Thursday before more weak surface high pressure builds
in. Cold front well to our west approaches slowly for Friday and
the weekend while decaying, keeping things unsettled this
weekend and even into Monday. Yet another cold front may come
through around the time frame of Monday/Tuesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Ample fair weather cumulus persists across the region this
afternoon, with high temperatures on track to reach the upper
70s to low 80s. Winds remain light and northwest for most of the
area, but a seabreeze slowly advancing inland is beginning to
turn winds out of the S/SE for areas along the coastal plain.

High pressure off to the east will result in widespread onshore
flow overnight. The previous cold front returns northward as a
warm front by Thursday morning, winds shifting S/SW. With the
onshore flow, low cigs/fog likely develops late tonight.
Guidance has trended a bit more conservative with how far west
the marine layer extends inland, currently looking to make it
just west of PHI. Sun and S/SW flow by morning will aid in
dissipating this after sunrise.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
High pressure and mostly dry conditions prevail Thursday and
Friday. The main question for this forecast period will be
temperatures, as a weak cold front is progged to move through on
Thursday. Timing of the frontal passage and ultimate strength
of the front will determine how warm temperatures get on
Thursday, but guidance has trended slightly warmer, especially
east of Philly as the front deteriorates. Temperatures max out
in the upper 60s to low 70s on Friday.

Shortwave energy could linger overnight Thursday so an isolated
shower or two could develop. Otherwise, precipitation doesn`t
arrive until late Friday night to early Saturday morning as
another front approaches.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Unsettled conditions are expected for the bulk of the extended
period. Weak ridging overhead on Saturday erodes through the
weekend as a shortwave trough digs to the north. An associated
cold front brings shower activity on Saturday and Sunday, but
could fall apart before moving through completely, or stall in
the vicinity. High pressure could briefly build in again on
Monday before a second stronger cold front sweeps through to
clean out the previous boundary.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Light NW flow prevails for the most part today with VFR
conditions expected, though a slowly encroaching seabreeze is
bringing onshore SE flow to some of the eastern terminals.

Tonight...VFR conditions are expected to start but low cigs/fog
are expected to develop with the marine layer as it moves
inland. Guidance has trended more conservative with how far west
the marine layer extends, so for now keep it east of PHI.
Conditions should improve shortly after sunrise.

Outlook...

Thursday through Friday night...Mainly VFR.

Saturday/Sunday...Sub-VFR conditions probable with increasing
chances for showers.

&&

.MARINE...
While winds are expected to remain below SCA, onshore flow could
bring fog, potentially dense, to the near shore waters and
inland late tonight. There is some uncertainty on if low stratus
or fog is more favorable to develop, but will continue to
monitor for potential of marine dense fog.

Outlook...

Thursday through Saturday...No marine headlines anticipated.

Sunday...SCA flag possible. Seas may build to 5 feet in some
locations, wind gusts 20-25 kts possible. Rain showers likely.

&&

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

&&

$$

SYNOPSIS...Wunderlin/Skeen
NEAR TERM...Skeen
SHORT TERM...Skeen
LONG TERM...Skeen
AVIATION...Skeen/Wunderlin
MARINE...Skeen/Wunderlin