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300
FXUS61 KPHI 070613
AFDPHI

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

.SYNOPSIS...
Cold front slows/stalls over the region tonight. Very weak high
pressure to the southwest begins to build in Friday, holding some
influence Friday night through Saturday. Cold front approaches
Saturday night and looks to pass through Sunday. Another cold front
may pass through Monday. Weak high pressure builds in for
Tuesday into Thursday.

&&

.NEAR TERM /THROUGH TODAY/...
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The dry air associated with a cold front is sliding through the
region this evening with a noticeable drop in dew points and
some cloud cover. Light ground fog is starting to show up in the
protected river valleys across western PA so as temps drop and
dew point depressions approach 1-2 degrees we may see some
light patchy fog develop. Even so, with dew points dropping into
the 50s it will feel much less humid across the region.

By day break the dry air should push through the region 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.
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&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
Summary...Fairly benign short term looks to be on tap. Generally no
precipitation expected Friday night through Saturday. Showers
possible Saturday night. Showers and thunderstorms more possible
Sunday with approach and passage of a cold front. Our region is not
outlooked for any excessive rainfall by WPC or any severe weather by
SPC for the short term.

An upper-level low looks to be centered north of the region Friday
night. This upper-level low will move eastward with time as another
lobe of upper-level low pressure swings down from the northwest and
over the Great Lakes region. A new upper-level low looks to be
centered just north of the northeastern CONUS for Sunday as a
trough-axis approaches our region from the northwest.

At the surface level, very weak surface high pressure looks to be
centered over the Mississippi River Valley Friday night. This weak
high looks to move eastward with time and be centered more over the
southeastern CONUS for Saturday. Meanwhile, a cold front looks to
approach from the northwest Saturday/Saturday night. The cold
front looks to cross through our region during the Sunday time
frame.

Our region will look to feel the influence of that weak surface high
Friday night through Saturday. With the surface high being weak to
the south, and broad upper-level low pressure and shortwave energy
being in place, some isolated pop-up showers should not be ruled out
entirely for Friday night or Saturday. Generally though, things
should be fairly benign weather wise during these periods; NBM
supports no PoPs for this time frame. We will see PoP chances
increase from the northwest later Saturday night into Sunday due to
the cold front. Timing of cold frontal passage is not very certain
at this point given the overall pattern. Chance for showers and
thunderstorms should be anticipated for Sunday due to the front.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
An upper-level trough looks to stall over the eastern CONUS Sunday
night into Tuesday while weakening. Though a more zonal upper-level
pattern looks to take hold over the CONUS Tuesday onwards, this
decaying and weak upper trough may continue to linger over the
eastern CONUS into Thursday.

The upper-level pattern suggests weak high pressure will mainly
influence the region at the surface level through much of the
long term; though another cold front may pass through around
Monday. However, with surface high pressure remaining weak and
an upper-level trough remaining through much of the time frame,
a bit of an unsettled long term looks to be on the horizon.
Though unsettled, nothing all that impactful looks to be on tap
at this point.

Slight chance for showers and thunderstorms each afternoon and
evening (Monday, Tuesday, Wednesday, Thursday) due to lingering
upper-level trough, possible shortwave energy, and weak high
pressure unable to suppress development. Temperatures right
around average through the term.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Prevailing VFR. Can`t rule out some patchy ground fog
developing mainly along the coastlines but not expecting
any prevailing restrictions. Winds should be light westerly
around 5 kt or less.

Friday...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.

Outlook...

Friday night through Tuesday...Generally VFR. Some sub-VFR
conditions possible Sunday/Sunday night. Moderate confidence.
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&&

.MARINE...
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A pre-frontal trough passes through this evening, followed by a
cold front tonight. Another cold front passes through on
Friday. Thunderstorms this evening may be strong to severe with
damaging wind gusts and heavy rain.

Westerly winds 10 to 15 kt overnight and should 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...

Friday night through Tuesday...No marine headlines anticipated.

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. 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
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&&

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

$$

SYNOPSIS...Wunderlin
NEAR TERM...Deal/MJL/MPS
SHORT TERM...Wunderlin
LONG TERM...Wunderlin
AVIATION...MJL/MPS/Wunderlin
MARINE...MPS/Wunderlin
TIDES/COASTAL FLOODING...