343
FXUS61 KPHI 182019
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
419 PM EDT Wed Sep 18 2024

.SYNOPSIS...
A coastal low will meander off the Mid-Atlantic coast through Friday
bringing several chances for showers across the area. The low
departs the area on Saturday as high pressure builds in over the
weekend into early next week. A cold front may approach the area by
the middle of next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
A weak coastal low, currently off Delmarva, will track to a position
off New Jersey tonight. This will keep a N to NE flow in place. At
the same time, a mid-level low over the Carolinas will continue to
drift NE. What looked to be a cloudy and dreary period with on and
off showers for much for the forecast area now looks that way only
from about the I95 corridor eastward. The N winds across the
interior are drier and the forecast is reflecting that.

So going forward with PoPs, most of us will fall in the chance
category into this evening. I do have likelies south and west. For
tonight, I basically have likelies along the coast with chance to
slight chance west of this. For tomorrow, I don`t have any PoPs
across the Lehigh Valley, Berks, and the southern Poconos. I have
slight chance to chance elsewhere. WPC no longer has a MARGINAL risk
for excessive rainfall for the New Jersey coast.

Temperatures tonight will range form the mid 50s to mid 60s. Highs
on Thursday will range from the mid 70s to low 80s.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
An unsettled short term period is in store, but it will not be
raining everywhere the entire time. A deep upper trough will remain
situated over the East Coast through the term before finally
pivoting away for the second half of the weekend. As the surface,
the weak surface low causing our weather today, will continue to
meander off the coast of Long Island through Friday night before
departing later on Saturday.

This combination will cause mostly cloudy skies to persist across
the entire region with chances for showers throughout the period,
mainly over northern and eastern New Jersey. Densest cloud cover and
greatest PoP chances will be found in these areas which will lie
within closer proximity to the surface low. Further west over parts
of E PA, there may be some clearing at times and more likely to
remain dry through the term. High temps will be rather uniform in
the 70s with the warmest temps found over western areas where
clearing skies may occur at times. Lows will mainly be in the upper
50s to mid 60s both Thursday and Friday night.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The long term period as a whole looks to be tranquil before having
to monitor the next precipitation potential around midweek. The
upper trough will exit the region by Sunday as a brief and weak
upper level ridge fills in on Monday. During this time, surface high
pressure will be building over New England which will yield tranquil
weather through Monday. Heading into the middle portion of next
week, a leading shortwave will be quickly approaching around the
Tuesday timeframe ahead of a deep upper trough. This will bring the
return of some showers to the area as a cold front approaches around
mid-week.

In terms of temperatures, highs will be a bit below average and lows
will be close to normal for late September standards.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight...VFR for the Lehigh Valley terminals. MVFR to VFR for the I-
95 corridor terminals. MVFR with a sprinkle of IFR for the South
Jersey terminals. Scattered showers. N to NE winds 5-10 kt. Moderate
confidence overall.

Thursday...Mainly VFR. The exception could be KACY with some MVFR in
the morning. Some morning showers possible at KACY. Moderate
confidence overall.

Outlook...

Thursday night through Saturday...Primarily VFR for all terminals,
with localized MVFR possible especially for KMIV/KACY with a chance
of rain showers.

Saturday night through Monday...VFR. No significant weather
expected.

&&

.MARINE...
Small Craft Advisory in effect for our ocean waters through Thursday
with seas around 5-7 feet. Winds out of the northeast around 15-20
kts with some gusts around 25 kts.

Outlook...

SCA conditions will likely persist through the weekend into at least
early next week due to a prolonged duration of winds and seas. North-
northeast winds around 15-20 kt with occasional gusts around 25-30
kt. Seas of 4-6 feet building up to 6-8+ feet through Monday.

Rip currents...

For Wednesday, east winds will decrease slightly to around 15
mph but breaking waves remain 2-4 feet with an 8-9 second
period. Therefore, the HIGH risk for the development of
dangerous rip currents was maintained and a Rip Current
Statement remains in effect through Wednesday for all beaches.

For Thursday, winds are forecast to shift more shore parallel
out of the north-northeast and decrease to 10-15 mph. Breaking
waves 3-4 feet with a 6-8 second period. Currently, a MODERATE
risk for the development of dangerous rip currents is forecast
for all beaches as a result.

For Friday, winds are forecast to pick up a bit to 15-20 mph.
North-northeast to northeast winds more onshore for Ocean
County NJ northwards; more shore parallel for areas southwards.
Currently, with breaking waves forecast to be a bit higher for
Ocean County NJ northwards, a HIGH risk for the development of
dangerous rip currents is forecast for Ocean and Monmouth
beaches in NJ while a MODERATE risk is forecast for areas
elsewhere.

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

&&

.TIDES/COASTAL FLOODING...
Continued onshore flow will result in water piling up and unable
to drain within tidal waterways. Minor tidal flooding is
expected for at least the next several high tide cycles for
portions of our area.

Coastal Flood Advisories were posted for the New Jersey coast,
Delaware Coast, and part of the Delaware Bay (Cumberland County
in New Jersey and Kent County in Delaware) as minor tidal
flooding is expected around high tide through the end of the
week at least. As a result, the Coastal Flood Advisory is not
just for tonight`s high tide, but through the high tide Friday
afternoon. Some of the guidance indicates moderate flooding
towards the end of the week, but will stick with the advisory
for now.

For the upper Delaware Bay and the tidal Delaware River, only
spotty minor tidal flooding is expected for this week.

No tidal flooding is expected along the northeastern shore of
Maryland currently at the moment.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory from 7 PM this evening to 3 PM EDT
     Friday for NJZ012>014-020>027.
     High Risk for Rip Currents until 8 PM EDT this evening for NJZ014-
     024>026.
DE...Coastal Flood Advisory from 7 PM this evening to 3 PM EDT
     Friday for DEZ002>004.
     High Risk for Rip Currents until 8 PM EDT this evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ450>453.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ454-455.

&&

$$

SYNOPSIS...DeSilva/MJL
NEAR TERM...Kruzdlo
SHORT TERM...DeSilva
LONG TERM...DeSilva
AVIATION...DeSilva/Kruzdlo
MARINE...DeSilva/Kruzdlo
TIDES/COASTAL FLOODING...