024
FXUS61 KPHI 051440
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1040 AM EDT Sun May 5 2024

.SYNOPSIS...
A warm front will lift north through the region today, and then
a cold front works its way through the region late Monday and
Monday night. This boundary will become stationary over the area
through the mid-week period. A series of disturbances will
track along this boundary through the middle of the week. A
stronger area of low pressure moves through the region on
Thursday, followed by a cold front on Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Weak warm advection overruning a very moist and cool marine
layer will keep low clouds and light rain showers for most
locations for the rest of the day. Forcing will be maximized
over the Lehigh Valley, but as a shortwave moves over the
region, the area of showers will push east through the afternoon
and evening. Temperatures will be in the upper 50s/low 60s,
though as a warm front advances slowly northward, some areas in
lower Delmarva will reach the upper 60s to lower 70s.

The bulk of the rain moves out late this evening, but a cold
front approaching tonight will reinforce lift and generate
additional showers. Some of the model soundings show some
elevated instability, so can`t rule out some lightning strikes
late tonight, mainly within Delmarva and the southern half of
New Jersey, along and south of the warm front. Some patchy fog
is possible with a moist boundary layer, greatest chance mainly
north and west of the Philadelphia metro. It will be a mild
night, with lows in the mid to upper 50s/low 60s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Cold front will be west of the area Monday morning. Southerly
flow ahead of that front will usher an increasingly humid
airmass into the region with surface dewpoints rising into the
60s. Areas of fog will develop in the morning, and then will
lift and dissipate by midday or so. The cold front passes
through the region Monday afternoon and Monday evening. Some
shortwave energy passing through the region will help kick off
afternoon and evening showers and thunderstorms, mainly across
the southern portions of the forecast area.

The front becomes stationary south of the region Monday night
through Tuesday night. High pressure builds north of the region,
and an onshore flow develops, bringing somewhat cooler and drier
air down into the region. Another disturbance approaches from
the west late Tuesday and Tuesday night, touching off another
round of scattered showers and thunderstorms over the region.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A prolonged period of unsettled weather on tap for the latter
part of the new week. A series of frontal boundaries and weak
low pressure systems will pass through the region during this
time. The first system is an area of low pressure that will pass
north of New Jersey Wednesday morning, and this will drag a
cold front through the region late in the day and at night. Some
rain is possible in the morning, and then another round of
showers and mostly isolated thunderstorms will affect the area
Wednesday afternoon and Wednesday evening.

The next area of low pressure will organize and develop over
the Midwest, and a warm front will develop out ahead of this
system and lift towards the local area late Wednesday
night/early Thursday morning. This will touch off some more
showers and isolated thunderstorms during this time. A secondary
low will form over the Mid-Atlantic ahead of the primary low,
and this low works its way across the region Thursday afternoon
and Thursday night. More widespread showers and scattered
thunderstorms will affect the area during this time.

The primary low passes north of the region on Friday with yet
another round of showers as a cold front passes through the
region.

Temperatures during the period will start out warm with highs
in the 80s on Wednesday,and then temperatures will trend closer
to normal on Thursday and Friday.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

This afternoon...Ceilings at or below 1Kft this afternoon with
ceilings 3-4Kft across southern Delaware and southeastern New
Jersey. Highest concentration of showers should move through
the Lehigh Valley and Delaware Valley.

Tonight...Low clouds and patchy fog. South to southeast wind
around 5 kt.

Outlook...

Monday through Thursday...No significant weather expected Monday
through Thursday morning. Widespread showers and thunderstorms
Thursday afternoon.

&&

.MARINE...
No marine headlines expected through tonight as seas will be 2 to 4
feet with winds out of the east/southeast around 10-20 kt. Periods
of showers expected, with a 15-20% chance of thunderstorms early
Monday morning.

Outlook...

Monday through Thursday...A prolonged period of sub-SCA
conditions. VSBY restrictions in fog throughout the week,
especially at night. Best chances for widespread showers on
Thursday afternoon.

&&

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

&&

$$

SYNOPSIS...Franklin/MPS
NEAR TERM...Franklin/Hoeflich
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...Franklin/Hoeflich/MPS
MARINE...Franklin/Hoeflich/MPS