338
FXUS61 KPHI 160134
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
934 PM EDT Wed May 15 2024

.SYNOPSIS...
An area of low pressure will remain offshore of the Mid Atlantic
coast through Friday, before drifting out to sea. High pressure
tries to build down into the area from the northeast over the
weekend, but never fully makes it into the area before another area
of low pressure moves across the central Appalachians and offshore
of the North Carolina coast later Sunday into Sunday night. Weak
high pressure may finally build across the area early next week,
before a cold front moves across the east coast by mid week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 9:30PM...Forecast remains on track. Occluding surface low
pressure remains centered just offshore of Delmarva and
southern NJ. Light rain and drizzle continues for areas across
the region along with some light patchy fog.

The occluding surface low pressure just offshore of the region
this evening will stall through tonight and into Thursday.
Chances for precipitation will diminish slightly with time
tonight as the low nudges just a little to the east/northeast,
but overall things will basically stay the same. Expect overcast
skies tonight with areas in NJ and near the coast seeing
continued drizzle or light rain. Some areas may see some patchy
fog into Thursday morning, but any widespread dense fog is not
expected.

For Thursday, not a lot of change is expected as the low will be
drifting out to sea but only very slowly. This will keep it mainly
cloudy with breezy north to northeast winds and some spotty light
rain and showers around, once again, especially in NJ and near the
coast. Western parts of the forecast area from around Berks County
northward into the Lehigh Valley should see a mostly dry day. Expect
highs mostly in the 60s (near 60 at the coast) except some low 70s
possible in our western zones from Chester and north through Berks
Counties and then into parts of the Lehigh Valley.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
Low pressure remains pinwheeling offshore of the Mid Atlantic coast
Thursday night through Friday, before finally moving out to sea
Friday night. There might be a few lingering showers near the New
Jersey coast early Thursday night, but the forecast dries out for
Friday as high pressure tries to begin nosing down into the area
from the northeast. Most of Friday night should remain dry as well,
except possibly late in the overnight showers may begin to move in
from the west.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Unsettled weather can be expected for portions of the area this
weekend, especially for the southern third of the area from
southern New Jersey, Delaware, and eastern Maryland. As an area
of low pressure will move across the central Appalachians, then
offshore of the North Carolina coast Saturday into Sunday, a
warm front will lift northward, but remain south of the area.
However, there will be enough moisture and lift across the area
for periods of showers to develop across the southern areas.
High pressure tries to build down from the north, but never
fully sets in, but it may have enough effect on the area to keep
the weather mostly dry for the northern portions area; however,
there will remain a chance of showers even for northern areas
given the proximity of the low and front to the south.

By early next week, the low pressure to the south will begin to
drift out to sea, while high pressure briefly affects the Mid
Atlantic region. Dry weather is expected Monday into Tuesday. As we
move into next Wednesday, a cold front is forecast to move into the
eastern seaboard, bringing an increase in shower chances.

&&

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

Tonight...Mostly MVFR expected for sites, though periods of IFR
likely for KACY/KMIV. KRDG/KABE will likely flirt with VFR
conditions at times. Some lingering spotty light rain, drizzle
and mist/fog for I-95 sites and eastward, especially for KACY.
NE winds 10-15 kts backing N during the first half of the
period. Low confidence.

Thursday....Mainly MVFR cigs throughout the day. N to NE winds
10-15 kts with some gusts to around 20 kts. Moderate confidence.

Outlook...

Thursday night...IFR then MVFR conditions expected with a chance of
showers.

Friday-Saturday...VFR conditions expected.

Saturday night...VFR conditions early, then MVFR or IFR ceilings
overnight with a chance of showers.

Sunday-Sunday night...MVFR or IFR conditions with a chance of
showers.

Monday...Conditions improving to VFR.

&&

.MARINE...
North to northeast winds will remain fairly strong over the waters
into this evening before starting to come down somewhat by later
tonight into Thursday. Remaining Gale conditions off the coast
of NJ (Gale Warnings in effect) should diminish to SCA levels
from south to north through tonight. Small Craft Advisory levels
conditions over the Delaware Bay diminishing this evening. Seas
6 to 10 feet through most of tonight diminishing to 5 to 7 feet
by later Thursday.

Outlook...

Thursday night...Small Craft Advisory level seas likely continue
through the night, but winds diminish below advisory levels during
the overnight.

Friday...Small Craft Advisory levels seas may continue into Friday.

Friday night-Saturday night...Conditions remain below advisory
levels.

Sunday-Monday...Small Craft Advisory conditions possible, mainly due
to seas although winds could gust around 20 knots.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ430-431.
     Gale Warning until 4 AM EDT Thursday for ANZ450.
     Gale Warning until midnight EDT tonight for ANZ451.
     Small Craft Advisory until 6 AM EDT Friday for ANZ452>455.

&&

$$

SYNOPSIS...Robertson
NEAR TERM...Fitzsimmons/Wunderlin
SHORT TERM...Robertson
LONG TERM...Robertson
AVIATION...Fitzsimmons/Robertson/Wunderlin
MARINE...Fitzsimmons/Robertson/Wunderlin