012
FXUS61 KPHI 030700
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
300 AM EDT Mon Jun 3 2024

.SYNOPSIS...
A weak system moves through the area through Monday. High
pressure moves in on Monday Night remaining in control through
early Wednesday. An upper level low then will move into the
Great Lakes, keeping things unsettled into next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
300 AM...A weak surface trough lingers in the area early this
morning oriented NE to SW near the I-95 corridor while in the
upper levels a decaying wave is moving through. This has
resulted in some showers that have become a bit more widespread
over the past hour or so over Delmarva and southern NJ. Expect
these showers to continue through the predawn hours before
exiting off the coast around or shortly after sunrise. There is
also a little bit of instability so it`s possible there could
also be a few rumbles of thunder.

Any lingering showers and isolated thunderstorms across southern NJ
and southern Delmarva will clear out shortly after daybreak with a
dry period from mid morning through early afternoon. Another
shortwave will pivot around an offshore upper low across the region.
Any cloud cover lingering early in the morning will scatter out
through the remaining morning hours and into the early afternoon for
much of the region, allowing for modest destabilization ahead of
this shortwave.

Hi res guidance shows MUCAPE values around the 1000 J/kg range by
the afternoon, and perhaps more notably DCAPE increasing to near
1000 J/kg as well. With dewpoints in the 60s, the ingredients are
there for a few scattered showers and thunderstorms to develop by
mid afternoon. With the dry mid- level air, convective initiation
(CI) will likely fail early in the afternoon. However, modest low-
level moisture and continued CI attempts in persistent areas should
eventually support some isolated to scattered convection by around
mid to late afternoon (3 PM onward). There will be some surface
convergence across the coastal plain across southern NJ, which
should be a focusing mechanism for CI, and will likely result in the
greatest coverage/strength of convection in this area as well. The
severe potential with these storms, however, will remain on the low
end with deep layer shear being rather lackluster in the afternoon
around 20 kts at best. Nevertheless, the higher DCAPE and mid-level
dry air could support some downbursts with any more robust cells
that are able to develop. With PWAT values in the 1-1.5 inch range,
a few good downpours may be possible with a stronger storm, but any
flooding concerns will be very localized and brief. High
temperatures are forecast to reach the mid 80s in most areas under a
mix of sun and clouds.

Showers/storms diminish Monday evening due to the loss of daytime
heating and also as high pressure starts to build in to the north.
This will result in skies starting to clear out with winds becoming
light onshore. This could lead to some patchy fog by the overnight
period across the coastal plain. Generally expect lows in the low to
mid 60s.


&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
We dry out through Tuesday as high pressure nudges in from the
north. With the high positioned just offshore, an onshore flow
will develop which will result in temperatures in the low to mid
70s near the coast, with upper 70s/low 80s elsewhere. Tuesday
Night should be dry, though the high begins to retreat offshore.
Clouds will increase through the night as the next system
approaches. Lows will drop into the upper 50s/low 60s.

A shortwave approaches for Wednesday ahead of a large upper
level low swinging down from Canada. This will result in some
showers and isolated thunderstorms moving through, primarily in
the afternoon and evening. Looking at some of the ensembles and
deterministic guidance, there really isn`t a strong signal for
any severe weather as instability looks meager. The same goes
for any shear. Thinking the day will be mainly cloudy, with some
periods of rain with some rumbles of thunder mixed in.
Temperatures will be in the upper 70s/low 80s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Long term period will be marked by unsettled weather due to a
closed low moving into the Great Lakes region and meandering
through the weekend. This will result in numerous shortwaves
rounding the base of the closed low and moving towards our
region with several associated frontal systems passing through
and an unsettled end of the week and weekend.

The strongest shortwave looks to approach on Thursday, with an
associated cold front moving through sometime late in the week.
Both the 00z and 12z guidance continues to speed up the timing
of the initial from to come through more towards Thursday
morning. This would limit the severe potential, compared to if
the front come through later in the day. Overall, the signal for
severe weather isn`t overly strong given the instability
currently forecast does not look that impressive. Out ahead of
the front, widespread showers and embedded thunderstorms look to
develop. Wednesday Night/Thursday time frame has the highest
rain chances (around 60-70%). Outside of that window, generally
expecting scattered showers and isolated thunderstorms, mainly
in the afternoon/early evening timeframe of Friday through
Sunday. PoPs for those days are only around 20-40%, so it is
fair to call it unsettled but not a total washout as the upper
level hangs around.

Temperatures will hover near or perhaps a touch below normal
for early June for the long term period.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Overnight...Some showers will continue to affect mainly MIV and ACY
early this morning and this could bring some brief restrictions to
these sites. Otherwise it should be VFR with winds generally light
out of the SW at around 5 knots or less. Moderate confidence.

Monday...Prevailing VFR conditions with scattered clouds. Chance
(30%-50%) of a shower/tstm after 18Z. Brief period of sub- VFR
conditions possible with a stronger storm. Moderate confidence.

Monday night...Primarily VFR. Some patchy fog possible (30-40%
chance) at KACY/KMIV. Winds becoming light onshore generally out of
the east at around 5 knots or less. Moderate confidence.

Outlook...

Tuesday through Tuesday Night...VFR. No significant weather.

Wednesday...Primarily VFR though showers/isolated thunderstorms
arriving late in the day could bring some restrictions.

Wednesday Night through Thursday...Restrictions likely (70-80%)
with widespread showers and scattered thunderstorms moving
through.

Thursday Night through Friday...Conditions should lift back to
VFR at some point but lingering showers/isolated thunderstorms
could result in further restrictions.

&&

.MARINE...
No marine headlines anticipated through Monday night however
expect some showers and potentially even a few thunderstorms
over the waters early this morning and again Monday afternoon.
Seas mainly 2 to 3 feet.

Outlook...

Tuesday through Wednesday...No marine headlines expected. Fair
weather.

Wednesday Night through Thursday...SCA conditions possible
(30-40% chance) with gusts nearing 25 kt. Periods of showers and
thunderstorms likely.

Rip Currents...

A LOW risk for the development of rip currents is in place for
Monday and Tuesday. While winds turn partially onshore for
Monday and then fully onshore for Tuesday, wind speeds will be
around 10 MPH, with continuing 1 to 2 foot waves and short to
medium period which keeps the overall risk for rip current
development low.

For specific beach forecasts, visit weather.gov/beach/phi

Rip currents occur often in the vicinities of jetties and
piers. Utilize any guarded beaches if venturing out into the
water.

&&

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

&&

$$

SYNOPSIS...Hoeflich
NEAR TERM...Fitzsimmons/MJL/Staarmann
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Fitzsimmons/Hoeflich
MARINE...Fitzsimmons/Hoeflich