256
FXUS61 KPHI 181925
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
325 PM EDT Mon Aug 18 2025

.SYNOPSIS...
High pressure sets up to the north while a boundary stalls out to
the south. A trough moves in during the middle of the week as
Hurricane Erin passes offshore. As Hurricane Erin moves away, high
pressure moves in for the end of the week and into the weekend
before a frontal system moves in for the back half of the
weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
Breezy onshore flow along the coast today will persist through the
early evening. A few light showers and drizzle will linger the rest
of today and into tonight, mainly for southern New Jersey and the
Delmarva.

High pressure centered over southern Quebec and northern New England
will dominate the weather through Tuesday. The resultant breezy NE
to ENE onshore flow across the region tonight and into Tuesday will
be mostly cloudy and cool conditions. Lows tonight will be in the
mid 50s to mid 60s with highs Tuesday about 5-10 degrees below
climo, only warming into the low to mid 70s! A stationary frontal
boundary lingering across Virginia will remain as an axis for some
shower development. A few isolated light showers and some patchy
drizzle will remain possible into Tuesday, mainly for southern New
Jersey and the Delmarva. Some clouds may try to break Tuesday
afternoon for northern New Jersey, but not completely, staying at
least partly to mostly cloudy for the day.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Unsettled and cool through the middle of the week. A stalled
boundary will remain perched just south of the region with high
pressure over the Canadian Maritimes. This will result in a breezy
onshore flow, which will only be enhanced by Hurricane Erin which
makes its closest pass on Thursday, bringing dangerous rip currents
and high surf (see Marine section below for more details).

Tuesday Night will feature mostly cloudy skies with some light
showers near the stalled front, mainly over the southern half of the
region. Some patchy fog is likely as well with moist onshore flow
continuing and strengthening.

More widespread showers and maybe a rumble of thunder on Wednesday
as an upper level trough approaches, the same trough that will
eventually carry Hurricane Erin out to sea. Rain chances are around
20-40% across the region and any precipitation will be light and non
impactful. Cloudy and cool otherwise with highs in the mid to upper
70s.

Mainly dry on Wednesday Night outside of some showers near the coast
as Hurricane Erin makes it closest pass well offshore. Again, cannot
rule out some patchy fog either. Lows settle in the low to mid 60s.

Upper level trough passes on Wednesday Night into Thursday, pushing
Hurricane Erin out to sea. Erin will end up passing around 450 miles
southeast of the New Jersey coast, with the main impacts being felt
along the coast with dangerous rip currents, high surf, and
enhancing onshore flow leading to tidal flooding and beach erosion.
Hurricane Erin will also enhance the pressure gradient, leading
to wind gusts up to 35 MPH at the immediate coast. Breaking
waves over 8 feet and seas offshore around 12 to 15 feet are
likely as well. Other than coastal impacts, and maybe a few
light showers around the shore, it should be a rather benign day
elsewhere with highs in the upper 70s and low 80s.

For the updated Hurricane Erin forecast, see the National Hurricane
Center`s website at www.nhc.noaa.gov.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The long term period looks rather quiet outside of a frontal system
approaching Saturday Night into Sunday. Temperatures look to
moderate towards more normal levels towards the end of the week and
into the first half of the weekend with generally dry weather. It
will turn more unsettled with that frontal system approaching but
too early to say specific impacts with that incoming system at this
time.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of today...An MVFR stratus deck will persist through much
of the remainder of the daytime. Some slight improvements to
cigs possible late day at RDG and ABE with low VFR indicated
here after 20z. A slight chance of light rain showers near
KACY/KMIV, otherwise dry conditions. Winds northeast 10 to 15
knots with gusts of 20 to 25 knots possible. Moderate
confidence.

Tonight...Some continuing improvement to low VFR cigs possible
from north to south but confidence is low on this since onshore
flow will be persisting. ACY/MIV expected to stick with MVFR
ceilings longer overnight, but times of VFR are still possible.
Winds generally east/northeast 5 to 10 knots. Low confidence.

Tuesday...Mainly VFR except there still could be some lingering
MVFR stratus at MIV and ACY through at least the morning. A
light shower or patchy drizzle may briefly impact MIV/ACY as
well. East winds around 7-12 knots, gusting to 15-18 knots. Low
confidence.

Outlook...

Tuesday Night...Primarily VFR...though areas of MVFR possible with
15% chance of showers and 15-20% chance of fog developing.

Wednesday through Wednesday Night...Restrictions likely (60-80%)
with scattered showers and patchy fog.

Thursday...Primarily VFR, though cannot rule out some restrictions
with patchy fog and stratus in the morning. Wind gusts 25-30 kt
possible at KACY, 20-25 kt at KMIV, and 20 kt elsewhere.

Thursday Night through Saturday...VFR. No significant weather.

&&

.MARINE...
Small Craft Advisory conditions through the period. Northeast
winds 20-25 gusting up to 30 knots early, diminishing to around
20 kts with gusts up to 25 knots tonight and into Tuesday. Seas
6 to 8 feet through tonight will become 5 to 7 feet Tuesday.

Outlook...

Tuesday Night through Saturday...A Small Craft Advisory is in
place for all ocean zones through Friday as seas associated with
Hurricane Erin gradually build, peaking up to 15 feet on
Thursday as Erin makes her closest pass to the New Jersey and
Delaware coast. Seas of 5 to 8 feet are expected Tuesday Night
through most of Wednesday night, with 10 to 15 seas anticipated
Thursday morning through early Friday morning, gradually waning
into the weekend.

Winds will be out of the northeast and generally remain below 25 kt
through Wednesday, before picking up Wednesday Night. Winds peak on
Thursday with Gale conditions possible (50-55%) with gusts near/over
35 kt. Winds gradually wane Thursday Night into Friday, and get
below 25 kt by Friday afternoon. Lingering 5 foot seas or higher
could continue into the weekend.

Rip currents...

Through Tuesday, northeast to east winds 10-25 mph. Breaking
waves of 2-4 feet in the surf zone increase to 3-6 feet during
Tuesday. Increasing long period swells propagating from
Hurricane Erin are expected to begin arriving on Tuesday. Given
these factors, a HIGH risk for the development of dangerous rip
currents continues for the Jersey Shore and the Delaware Beaches.

For Wednesday, northeast to east winds 10-20 mph. Breaking waves
in the surf zone are forecast to build into the 5-8 foot range,
with conditions worsening through the day as long period
southeasterly swells (15-18 seconds) associated with Hurricane
Erin continue. Due to the dangerous conditions, a HIGH risk for
the development of dangerous rip currents continues for the
Jersey Shore and the Delaware Beaches.

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

&&

.TIDES/COASTAL FLOODING...
Prolonged onshore flow will result in periods of tidal flooding
this week. Minor tidal flooding is expected with this
afternoon`s high tide cycle for the southern New Jersey coast
and Delaware coast, with a Coastal Flood Advisory in effect
through this upcoming high tide cycle. Otherwise, any tidal
flooding should be spotty minor for the rest of the New Jersey
coast and Delaware Bay.

Water will slowly pile up as onshore flow continues through at
least Thursday. Swells from Hurricane Erin will also enhance
the threat for tidal flooding and push of water onshore,
especially as it gets closer to Wednesday into Thursday. Stay
update on the latest forecasts and be aware of any Coastal
Flood Advisories or Warnings that are issued.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory until 10 PM EDT this evening for
     NJZ022>025-027.
     High Risk for Rip Currents through Wednesday evening for NJZ014-
     024>026.
DE...Coastal Flood Advisory until 10 PM EDT this evening for DEZ003-
     004.
     High Risk for Rip Currents through Wednesday evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ430-
     431.
     Small Craft Advisory until 6 PM EDT Friday for ANZ450>455.

&&

$$

SYNOPSIS...Hoeflich
NEAR TERM...MJL
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Hoeflich/MJL
MARINE...Gorse/Hoeflich/MJL
TIDES/COASTAL FLOODING...Hoeflich