697
FXUS61 KPHI 071403
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1003 AM EDT Fri Jun 7 2024

.SYNOPSIS...
Weak high pressure builds in this afternoon, holding some
influence through Saturday. A sequence of cold fronts cross
through the area on Sunday and again on Monday. Broad high
pressure returns for Tuesday with some unsettled weather
expected around mid-week.

&&

.NEAR TERM /THROUGH SATURDAY/...
Mid 50s to low 60s dew points have progressed to near the
coastal locations this morning however its not until the
afternoon before the wind shift arrives and the cold air
advection surge starts actually pushing in. The winds will
initially more west southwest in the morning but by later in the
afternoon the winds become west northwest and with that change
comes stronger mixing in the boundary layer. Gusty winds develop
this afternoon with winds generally blowing 10-15kts gusting up
to 25kts.

In addition there is some modest ML CAPE with the wind shift which
may be just enough to support an isolated shower making it towards
the Poconos but with the dry air and cold air advection I dont
anticipate much happening in the way of shower activity across the
region.

This evening should be tranquil with winds rapidly declining with
the decoupling of the boundary layer after sunset. Brief high
pressure builds in through Saturday keeping sensible weather dry to
start the weekend. With cold air advection through the evening 925mb
temps should be able 2 degrees cooler Saturday than Friday leading
to highs in the upper 70s to low 80s under partly cloudy to clear
skies.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Heading into Saturday night, zonal flow aloft sets up temporarily as
the first upper trough begins to pull away. A new upper level low
will then be centered north of the NE CONUS for Sunday as a
shortwave approaches the region. On Monday, the upper trough axis
will swing through the region.

At the surface, weak high pressure will begin to move off the
southeast coast on Saturday night allowing a cold front to approach
the region on Sunday. In wake of the front, broad but expansive high
pressure will begin to nose in from the west as a secondary cold
front passes through on Monday.

As a whole, Saturday night looks to remain dry other than a slight
chance of a rain shower in the Poconos. Increasing clouds are
expected with lows in the upper 50s to low 60s. PoPs will then
increase from northwest to southeast during the day on Sunday as the
initial front approaches. However, forcing is relatively weak so not
expecting much more than a 20-30% chance of showers and/or
thunderstorms on Sunday. Best chance will be north and west were
better forcing is present. By Sunday night, skies will begin to
clear and should remain at least partly cloudy on Monday. At this
point, Monday appears to remain dry as drier air looks to be in
place with the secondary frontal passage. Highs for Sunday and
Monday will be in the 70s to low 80s.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
The upper level trough eventually pulls away from the area on Monday
night and Tuesday. Beyond Tuesday, the forecast becomes vastly
uncertain as each of the global deterministic models show a very
different upper level pattern. The GFS has a cut-off upper low
meandering over the Great Lakes region, while the ECMWF has a upper
ridge over the same area. The CMC is more in line with the ECMWF,
but still has mixed signals of the two. Considering the differences
amongst guidance, have stayed in close relation to NBM guidance.
This maintains the slight chance of showers/storms during the
Tuesday through Thursday period. Temps look to remain seasonable
through Wednesday before moving above normal late in the week.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Today...VFR. An isolated SHRA may pass over KABE in the
afternoon. W winds increasing to 15 to 20 kt with gusts up to 25
kt.

Tonight...VFR with light westerly winds 6-10 kts.

Outlook...

Saturday through Tuesday...VFR expected. Slight chance for sub-
VFR conditions possible on Sunday with a shower or
thunderstorm. Otherwise, no significant weather is expected.

&&

.MARINE...
Another cold front passes through on Friday but is not expected
to bring showers.

Westerly winds increase back up to 15 to 20 kt during the day
today, though gusts should remain just below 25 kt.

Seas will average 3 to 4 ft.

Outlook...

Saturday night through Tuesday...No marine headlines expected. Winds
will occasionally gust around 13-18 kt through the period with seas
around 2-3 feet. Fair weather expected through Monday with a slight
chance of showers returning on Tuesday.

Rip Currents...

Gusty west winds will develop on Friday, ranging from 15 to 20 mph
with gusts up to 25 mph. With breaking waves of 2 to 3 feet, a
medium period swell, and a New Moon, there is a MODERATE risk for
the development of dangerous and life threatening rip currents at
New Jersey beaches, but a LOW risk at Delaware beaches.

On Saturday, the effects of the New Moon will not be as impactful,
and west winds will be much lighter. The swell will still be onshore
so there will be a Moderate Risk for Atlantic County where the rip
current risk is higher at low tide from roughly Longport to
Brigantine during the afternoon.  Elsewhere, with breaking waves
generally expected to be 1-2 feet there will be a LOW risk for the
development of dangerous and life threatening rip currents at New
Jersey and Delaware beaches.

Rip currents occur often in the vicinities of jetties and piers.
Utilize any guarded beaches if venturing out into the water. For
specific beach forecasts, visit weather.gov/beach/phi

&

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

&&

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

&&

$$

SYNOPSIS...DeSilva/Wunderlin
NEAR TERM...AKL/Deal
SHORT TERM...DeSilva
LONG TERM...DeSilva/Wunderlin
AVIATION...Deal/DeSilva
MARINE...AKL/Deal/DeSilva