637
FXUS61 KPHI 240221
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1021 PM EDT Thu May 23 2024

.SYNOPSIS...
A cold front will move across the area this evening. The front
will stall to our south on Friday before lifting back north on
Friday night as a warm front. Another cold front moves through
on Sunday with a stronger system impacting the area on Monday
into Tuesday. A secondary cold front looks to cross the area on
Wednesday into Thursday.

&&

.NEAR TERM /THROUGH FRIDAY/...
1015 PM...As of this time, a cold front extended from northern
NJ south and west through eastern PA. Most of the convection
that was occuring earlier to our west with this has died off
with just some very isolated storms left over SE PA. Farther
upstream, well to our south and west, there are more
showers/storms over portions of eastern Tennessee and Kentucky
associated with another upper level disturbance. As we go
through tonight, the cold front will gradually push south and
east reaching near or just south of the I-95 corridor by morning
as it approaches Delmarva. There will still be some isolated
showers and storms possible along it over SE PA into southern NJ
and and Delmarva but for much of the night they should be very
few and far between (POPs 20 to 30 percent or less). Late at
night, however, shower/storm chances increase over our southern
zones as the next disturbance referenced above approaches the
area. The best chances for precip will continue to be over
Delmarva into SE PA and southern NJ. Expect lows tonight mainly
in the 60s, except upper 50s over the Pocono Plateau into the
higher elevations of NW NJ.

As we go through Friday, a weak cold front should be stalling
across parts of Delmarva. The placement of this front along with
a trailing piece of energy may continue to support some showers
or thunder across our southern areas to start the morning. The
cloud cover will clearing from the northwest, with some mid to
high level clouds lingering the longest for our Delmarva to
southeastern New Jersey areas. As the low-level flow turns more
westerly in the wake of the front, drier air will arrive and dew
points are forecast to drop into the 50s for much of the area.
The dew points look to remain in the 60s however across Delmarva
to southeastern New Jersey. It will be a warm day with much of
the area getting into the 80s, although with lighter flow
expected a sea breeze should develop resulting in cooling closer
to the coast.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Tranquil weather will continue into Friday night with clear skies
and light winds initially. We should be able to radiate pretty well
leading to some patchy fog development over Delmarva and southern
New Jersey. However, clouds will increase from south to north later
in the night as the stalled front begins to lift back north across
the area. This should limit the amount of cooling late, so expecting
lows in the mid 50s to lower 60s.

For Saturday, the warm front will lift completely north of the area
as the main low pressure system tracks across the Great Lakes.
Saturday morning likely stays dry however, as we progress through
the afternoon, the chance for showers and thunderstorms increase
from west to east. For locations along the shore, precip should hold
off entirely until Saturday evening, although it will be a mix of
sun and clouds most of the day. This system will be a rather quick
mover so while Saturday night does appear to be wet especially north
and west, all precipitation should end by Sunday morning. The region
should dry out on Sunday as the front now looks to stall to our
north and west, resulting in sunny skies in the afternoon with some
fair weather clouds. Slight chance of a shower in the higher
elevations which remains closer to the stalled boundary. Aided by
warm air advection, highs on Saturday and Sunday should reach into
the low to mid 80s with cooler temps along the coast. Saturday night
lows will be in the mid 50s to low 60s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Beyond Sunday, the weather pattern becomes unsettled as a stronger
low pressure system develops back over the central CONUS. Strong PVA
will move over the region Monday with stronger cold front crossing
the area Monday night into Tuesday. This will lead to widespread
shower activity across the region. WPC has included a Marginal risk
for Excessive Rainfall and CIPS analog guidance is highlighting the
potential for severe weather across the Delmarva (10-15% chance) on
Monday and across the entire area on Tuesday (10% chance). Will
continue to monitor and focus attention on this time period of
Monday afternoon through Tuesday. After the cold front passes,
unsettled weather continues to be the theme thanks to several
waves/impulses aloft passing through the week.

Temps for the workweek should be fairly seasonable with highs in the
70s through Wednesday, before falling back into the 60s by
Thursday.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Tonight...VFR overall through this evening, however a few
showers and thunderstorms will be around which could result in
local and brief sub- VFR conditions. This threat exists mainly
from around ILG southward. Overnight, it`s looking like there
will be some low stratus and mist/fog that affects MIV and ACY
bringing sub VFR conditions. The threat exists for this at other
sites as well but chances for this are only around 30 percent so
it`s not included in the TAFs. Low confidence.

Friday...VFR overall except some lingering mist/fog and stratus
likely to start the day at MIV and ACY. Also, a few showers or
a thunderstorm will be possible early in the morning. Light and
variable winds becoming northwest around 5 knots, then becoming
west. A sea breeze may result in winds becoming south or
southeast at KACY and KILG in the afternoon. Moderate
confidence.

Outlook...

Saturday through Saturday night...VFR during the day, likely
becoming sub-VFR at night. Showers and thunderstorms late in the day
into the evening.

Sunday...VFR. No significant weather expected.

Sunday night through Tuesday...Sub-VFR conditions probable with a
chance of showers and thunderstorms especially on Monday into
Monday night.

&&

.MARINE...
The conditions are expected to remain below Small Craft Advisory
criteria through Friday, however a few gusty thunderstorms will be
possible this evening mainly across the southern coastal waters
including Delaware Bay.

Outlook...

Friday night through Tuesday...No marine headlines expected. Winds
will occasionally gust up to 15-20 kt with seas around 2-4 feet. A
chance for showers is expected on Saturday night with a chance for
showers and thunderstorms Monday into Tuesday. Marine fog is also
possible on Saturday morning.

Rip Currents...

For Friday, winds will once again be out of the S to SW at 5 to
10 mph with breaking waves of 1 to 2 feet. There is a LOW risk
for the development of dangerous rip currents at NJ and DE
beaches. Although there is a slight chance for showers,
thunderstorms are not expected.

The LOW risk for the development of dangerous rip currents is
expected to continue for Saturday.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will be elevated this week with a Full Moon
occurring today, May 23. Spotty minor coastal flooding will be
possible, especially for the back bays, around the times of the
evening high tide cycle, which will be the higher of the two
tide cycles, going into the end of this week.

&&

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

&&

$$

SYNOPSIS...Deal/DeSilva
NEAR TERM...Fitzsimmons/Gorse
SHORT TERM...Deal/DeSilva
LONG TERM...Deal/DeSilva
AVIATION...DeSilva/Gorse
MARINE...DeSilva/Gorse
TIDES/COASTAL FLOODING...