Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 150140
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
940 PM EDT Thu Mar 14 2024

.SYNOPSIS...
A cold front approaches the region tonight and looks to cross
through Friday. Weak high pressure builds in Friday night and
Saturday. Cold front approaches Saturday night looking to cross
through Sunday. Yet another cold front may pass through Monday
before high pressure returns for the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
935 PM...As of mid evening, low pressure was centered near Ohio
with an associated area of showers and storms pushing from Ohio
into western PA. Farther east from here the instability rapidly
wanes getting into to eastern PA towards the coast. For this
reason, even as the low and its associated showers move east
through tonight we expect that much of this activity should
weaken as it reaches eastern PA into NJ. We did make some minor
adjustments to the POP grids through the overnight hours with
the mid evening update. Best chances for seeing some showers
overnight look to be over our northeastern PA zones into NW NJ
closer to where the stronger forcing will be moving across.
Otherwise, it will be an unseasonably mild night with lows in
the 50s, and a light southwesterly breeze developing.

On Friday, low pressure will track across New England, sending a
cold front quickly southward across our region, pushing off the
NJ shore in the afternoon, and south of the Delmarva by the
evening. That has trended a little bit quicker, and models have
also lowered rainfall amounts, especially from around
Philadelphia northward, with less than 0.05 inches expected
there. Most of the morning looks largely dry, aside from a
passing light shower or two. A tenth to a quarter inch is still
possible across the Delmarva, as showers redevelop mainly from
around Philadelphia to Atlantic City pressing southward through
the afternoon. Would not completely rule out a rumble of
thunder from around Wilmington to Cape May southward in the
afternoon and early evening, but instability is really lacking,
and various calibrated thunder probabilities suggest that the
chances are less than 10 percent. High temperatures will still
be warm, in the 60s and 70s, but with the 70s limited to areas
where the front hasn`t come through in the afternoon...probably
just south of PHL to ACY.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Weak surface high pressure will begin to build in Friday night as a
cold front pushes further offshore. This weak surface high pressure
will influence the region Saturday into Saturday night. A rather
pronounced, but relatively dry, cold front will then approach the
region Saturday night and look to cross through around the time
frame of Sunday.

The region could see some lingering rain Friday night before the
cold front pushes further offshore. A couple rumbles of thunder
cannot be ruled Friday night but model soundings overall don`t
indicate anything impressive in terms of instability. Expect dry
conditions for Saturday with weak surface high pressure in control.
With the approaching cold front Saturday night, and its anticipated
cross through to begin some time Sunday, some light rain cannot be
ruled out during these periods. However, most of guidance continues
to indicate the front will remain relatively dry on approach and
cross through. A couple of light rain showers may occur in our
northwestern most areas but elsewhere should remain fairly dry for
the Saturday night and Sunday time frame.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The ensembles and deterministic models suggests surface high
pressure and a return of colder temperatures will be the main story
of the long term. Surface high pressure centered over the central
CONUS Sunday night and Monday will gradually make its way eastward
with time. This surface high pressure could be centered over the
eastern CONUS come the Wednesday/Thursday time frame.

With surface high pressure building in and influencing the region,
expect conditions to be fairly dry during the long term. However, it
is worth mentioning guidance does support a few cold fronts/rounds
of shortwave energy passing through during the term. Particularly,
another cold front from the northwest looks pass through the region
during the Monday/Tuesday time frame. Overall, a couple of rain/snow
showers may be in the cards during some periods. Regardless, given
the overall synoptic pattern, any showers that manifest should be
not be all that impactful.

Temperatures will look to be right around average to just slightly
below average during the term. Many areas will see high temperatures
return to the 40s/low 50s for Monday, Tuesday, and Wednesday next
week.

&&

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

Tonight...Mainly VFR with south to southwest winds generally
around 5 knots or so. A light rain shower possible (25-35%
chance), mainly northwest of the I-95 terminals later tonight. A
40kt low- level jet develops around 2kft overnight as well so
LLWS has been included in TAFs at all sites. Moderate
confidence overall.

Friday...Remaining VFR despite some showers rolling through,
mainly from PHL southward during the afternoon hours. Some MVFR
possible south of ILG and MIV into the Delmarva in the
afternoon, and would not completely rule out a rumble of thunder
down there. Ceilings elsewhere at the TAF sites may drop to 050,
and would not rule out brief MVFR VSBY restrictions as far north
as PHL, but more likely farther south. Winds in the morning SW
to W 10-12 kt, shifting to NW as a cold front passes through
from NW to SE from late morning into the afternoon. Moderate
confidence.


Outlook...

Friday night...Sub-VFR conditions possible. N/NW winds 5-10 kts.
Moderate confidence.

Saturday...VFR. NW winds 5-10 kts backing SW with time. Moderate
confidence.

Saturday night...Mainly VFR. SW winds 5-10 kts. Moderate
confidence.

Sunday...Mainly VFR. W winds 15-20 kts with gusts up to 30 kts.
Moderate confidence.

Monday...Mainly VFR. W winds 10-20 kts. Moderate confidence.

Tuesday...Mainly VFR. W winds 12-17 kts with gusts of 25-30 kts
possible. Moderate confidence.

&&

.MARINE...
Fair weather will continue into tonight across our marine zones.

However, south to southwest winds gradually ramp up tonight,
increasing to 15 kts with gusts around 20 kts.
Occasional gusts up to 25 kts possible, but should remain
isolated and mainly restricted to areas beyond 5-10 nm of shore,
so no advisories are anticipated. Southwest winds will then
gradually ease off after Friday morning, tending westerly 5-10
kt by the end of the day. Seas 1 to 2 ft this evening, then 2
to 4 feet late tonight through Friday.


Outlook...

Friday night through Sunday night..No marine headlines anticipated.
Outer areas of the oceans zones could flirt with 5 foot seas
Saturday night and Sunday morning.

Monday...SCA flag possible.

Monday night through Tuesday...SCA flag anticipated.

&&

.TIDES/COASTAL FLOODING...
Some spotty minor flooding was observed along portions of the
lower Delaware River during the predawn hours Thursday morning,
but water levels have receded. Similar but perhaps slightly
lower tide levels as we observed this morning can be expected
for the next couple high tide cycles this evening and early
Friday morning. Worst case would be just for a repeat of some
spotty minor flooding along the tidal Delaware and around upper
Delaware Bay. Astronomical tide levels will lower through the
weekend, ending any coastal flood threat.

&&

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

&&

$$

SYNOPSIS...Wunderlin
NEAR TERM...Dodd/Fitzsimmons
SHORT TERM...Wunderlin
LONG TERM...Wunderlin
AVIATION...Dodd/Fitzsimmons/Wunderlin
MARINE...Dodd/Wunderlin
TIDES/COASTAL FLOODING...


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