163
FXUS61 KPHI 211331
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
931 AM EDT Tue May 21 2024

.SYNOPSIS...
High pressure shifts slightly to the south today then out to sea
Wednesday. A cold front will approach the area Wednesday night,
before slowly moving across the area on Thursday, then stalls to our
south through the weekend. Several waves of low pressure and may
develop and move along this boundary over the weekend into early
next week, bringing unsettled weather to the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 9:30am...Current satellite imagery shows that the morning
fog is burning off rapidly. Expect the entire area to be fog-
free by about 10-11AM. Only minor changes were made to the
forecast, updating sky/temp grids basis ongoing obs.

Morning fog will give way to clear skies in the afternoon with
some fair-weather cumulus. Another dry and quiet weather day is
expected. High temps should be a bit warmer than yesterday,
rising into the low to mid 80s. Temps will be noticeably cooler
along/near the shore thanks to light surface winds allowing an
afternoon sea breeze circulation to develop.

Another tranquil night with mostly clear skies and calm winds. Light
SSW flow should inhibit much organized fog outside the immediate
coast, but some patchy fog will be possible. Lows in the mid
50s to around 60.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
High pressure will move farther away from the area and out to sea on
Wednesday, losing its effect on the weather across the area. Dry
conditions are expected early in the day on Wednesday, but showers
will be possible by the end of the day as a mid/upper level
disturbance moves in to the area. Showers and thunderstorms become
more likely on Wednesday night as a pre-frontal trough may develop
across the area while the aforementioned mid/upper level disturbance
slowly moves across the area.  Showers and thunderstorms become even
more likely on Thursday and into Thursday evening as the cold front
moves across the area. There is some instability forecast across the
area, with CAPE values potentially reaching 1000-2000 J/kg, with
some shear across the area with 30-40 knots. So there will be the
potential for some strong to severe storms to develop across the
area.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The cold front is expected to stall to the south Friday and into the
weekend, before possibly lifting north of the area on Monday.
leading to possible unsettled weather. A couple of waves of low
pressure are expected to move across the area as the front stalls
near the area Friday and Saturday. This will lead to a period of
possible unsettled weather with a chance of showers and
thunderstorms. As these disturbances move to the east Sunday, it is
possible that the shower activity will diminish on Sunday. However,
another area of low pressure could begin to move into the area
Sunday night into Monday, bringing addition unsettled conditions to
the area.

&&

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

Today...Any IFR/MVFR CIGs should rise to VFR by 14-15Z at all
terminals. Mostly clear skies during the afternoon. South-
southwest winds around 5-10 kt. High confidence.

Tonight...Prevailing VFR. Light and variable winds. Some patchy
fog possible, but forecast currently does not call for anything
more widespread than that. Moderate confidence.

Outlook...

Wednesday...Generally VFR except lower conditions possible around
daybreak.

Wednesday night-Thursday night...Sub-VFR conditions possible with a
chance of showers and thunderstorms.

Friday...VFR conditions expected with a slight chance of showers
during the day.

Friday night-Saturday...Chance of showers with periods of lower
conditions possible.

&&

.MARINE...
Marine conditions are expected to remain below small craft
advisory criteria. Light and variable winds this morning will
become more S to SSW this afternoon into the overnight period
around 10-15 kt with occasional gusts up to 20 kt. Seas 2-3
feet.

Outlook...

Wednesday-Saturday...Conditions expected to remain below Small Craft
Advisory levels.  However, winds will gust around 20 knots at times
and seas could rise to 4 feet at times.

Rip Currents...

Winds today will increase to 5-15 mph from the south to
southeast, while waves offshore waves will be 3-4 feet with an
8 second swell. Also, there is a full moon on Thursday. This
will all contribute to a Moderate risk for the development
of dangerous and life threatening rip currents for the beaches
both Delaware and New Jersey.

Similar conditions will continue into Wednesday, with slightly
stronger winds. As a result, there will continue to be a
MODERATE risk for the development of dangerous and lift
threatening rip currents at NJ and DE beaches on Wednesday.

&&

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

&&

$$

SYNOPSIS...Robertson
NEAR TERM...DeSilva/MJL
SHORT TERM...Robertson
LONG TERM...Robertson
AVIATION...MJL/Robertson
MARINE...DeSilva/MJL/Robertson