816
FXUS61 KPHI 092134
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
534 PM EDT Thu Oct 9 2025

.SYNOPSIS...
High pressure will continue to build into the area through
tonight. It will then shift offshore Friday into Saturday. A
coastal storm with significant impacts is expected to affect
the region by Sunday and into early next week. Conditions
improve as we get towards the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
With the high settling closer to the area, should have clear
skies and decreasing winds. This should lead to efficient
radiational cooling conditions, especially in areas away from
the urban centers. Models generally have a warm bias with
patterns like this, so have gone closer to the 25th percentile
for min temperatures. As such, added Lehigh County to the freeze
warning. Also issued a frost advisory for portions of South
Jersey. This is primarily to account for the Pine Barrens which
will likely be much colder than SW Jersey or coastal areas.

The center of the high should shift off shore by mid day Friday.
Consequently, low level flow will be shifting to easterly and
southeasterly resulting in moderating temperatures, with highs
tomorrow a degree or two higher than Thursday.

By Friday night, we are expecting to see increasing cloud cover
as the coastal low begins to develop. The cloud cover should
limit radiational cooling and preclude any additional frost or
freeze concerns.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Saturday will feature mostly cloudy to overcast skies with
temperatures moderating further into the upper 60s to low 70s in
most areas. While most are likely to remain dry during the
daytime Saturday, rain will begin to overspread the area, moving
into areas across the coastal plain SE of I-95 through the
afternoon. Easterly winds will begin to increase some,
especially later in the day closer to the coast.

Things really start to go downhill on Saturday night as a coastal
low approaches from the south. Rain is expected to continue
overspreading the area, with around a 60-80% chance of rain region-
wide. The heaviest rainfall will be focused over lower Delmarva
and the southern NJ coast, though rainfall rates should stay
below a quarter of an inch per hour (more on storm-total
rainfall in the long-term). Winds begin to increase, especially
over the water and along the immediate coastline with gusts
getting near 40-50 mph by daybreak.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
For the long term period over Sunday and into early next week, the
main feature of interest will be the development of a potentially
significant coastal storm near the North Carolina coast along a
stalled frontal boundary. This storm is anticipated to strengthen
and lift northward Sunday into early next week.

There remains a fair amount of certainty regarding the details of
the evolution of the coastal storm and its ultimate degree of
impacts. The primary impacts will be from coastal flooding, beach
erosion, strong to potentially damaging winds, and heavy rain. The
heaviest rainfall and strongest winds are still anticipated to be
near the Atlantic coast.

Sunday through Monday will be when our area likely experiences the
brunt of the impacts from the coastal storm. If the current track
holds and the coastal storm does end up just offshore or even making
landfall over Delmarva, strong winds are expected, sustained near 30-
40 mph (perhaps near 50 mph along the immediate coast) with gusts
possibly near 60 mph or greater along the coast by Sunday afternoon
and Sunday night. There is potential for these strong winds to
continue well into Monday. Gusts upward of 30-50 mph may extend
inland to about the I-95 corridor. While there is still some
uncertainty in how long strong winds last, there is at least high
enough confidence that counties bordering the Atlantic Ocean will
either see sustained winds or frequent wind gusts at/above criteria
for a High Wind Warning. As a result, went ahead and issued a High
Wind Watch for the coastal strip in both NJ and DE, and their
respective counties as periods of 40+ MPH sustained winds and/or
frequent gusts near 60 MPH are possible. Would not be surprised to
see a Wind Advisory for more inland counties, but will wait until
confidence is higher.

In addition to the wind, heavy rain is forecast, and a SLIGHT (2/4)
Risk Excessive Rainfall Outlook is in place for the I-95 corridor
and points south and east for Sunday through Sunday night. We are
not fully in the QPF period yet, but the WPC longer-range rainfall
products suggest a widespread 1-3+ inches of rain across our entire
area, with locally higher amounts of 3-5 inches possible,
especially within the SLGT risk area. The latest NBM QMD mean
forecast has around 3 to 4 inches along the New Jersey and
Delaware Coast, with 1.5 to 3 inches elsewhere. While that
sounds like a lot, it is important to keep in mind that this
will be falling over a 36 to 48 hour period. It has been quite
dry as well. Given this, the thinking is that flooding due to
heavy rain alone will be limited to poor drainage and urban
areas. However, that much rainfall could exacerbate impacts near
the coast with Moderate and potentially Major tidal flooding
ongoing. Significant high tides are expected due to strong
northeast winds resulting in water piling up along the coast.

With all that being said, there remains some uncertainty in the
track of the coastal low, even being within a few days of the event.
The setup is overall very complex. The surface low will be
developing over the Gulf Stream along a stalled boundary, and its
northward movement will depend on how it interacts with a surface
high over Nova Scotia, an upper level low over the Great Lakes, and
even distant Tropical Storm Jerry. A closer and slower evolution
would bring more significant impacts while a track further away
still will likely bring hazards, though not as severe. Stay tuned to
the latest briefing packages and forecast updates as the forecast
continues to change.

Things look to quiet down by Tuesday and Wednesday as the system
pulls away with rather benign weather and seasonable temperatures
for mid-October.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through tonight...VFR conditions. Few to scattered mid level
clouds around 4000 ft AGL possible especially before 00Z. Winds
around 10 kt out of the NNE, decreasing and shifting more to the
ENE after 00Z. High confidence.

Friday through Friday night...VFR with increasing mid level
clouds. Winds favoring the SE through much of the day on Friday,
could become light and variable Friday night. Moderate
confidence.

Outlook...

Saturday...Starting out VFR though conditions likely come down late
in the day as showers and low clouds overspread the area,
potentially bringing MVFR conditions to the South Jersey terminals
and possibly KPHL/KILG. Northeast wind gusts near 20 kt at KACY.

Saturday Night...MVFR/VFR conditions with light to moderate rain and
lower clouds overspreading the area. Highest chance for restrictions
at the South Jersey terminals. Northeast wind gusts 25-30 kt at
KACY, 20-25 kt at the I-95 terminals and KMIV, and 15-20 kt at the
Lehigh Valley Terminals.

Sunday through Monday...IFR conditions expected with moderate rain
moving through and gusty winds. Northeast wind gusts up to 50 kt
possible at KACY. Gusts out of the northeast around 25-35 kt
expected at the I-95 terminals and KMIV, with 20-30 kt anticipated
within the Lehigh Valley.

Monday Night...Restrictions expected with showers and low clouds.
Wind gusts diminish to around 15-25 kt out of the north/northeast.

Tuesday...Conditons improve but sub-VFR conditions possible. Wind
gusts could get near 20 kt at times.

&&

.MARINE...
On the waters, winds have mostly subsided below 25 kts and are
expected to remain so through tomorrow. For Atlantic Coastal
waters from the Manasquan Inlet southward, seas remain elevated
near or above 5 ft, so the Small Craft Advisory continues.

Seas should slowly subside into the overnight hours. Once they
do, expect conditions to remain below SCA criteria through
Friday.

Outlook...

Saturday...Conditions expected to begin to deteriorate, with
SCA conditions expected later in the day. Seas build to around 5
to 7 feet with winds increasing out of the east to around 20-30
kt.

Saturday Night through Monday...A Storm Watch remains in place
through this period for all marine zones except the upper Delaware
Bay. Northeast winds 35-45 kt and gusts up to 50-55 kt expected
within the Atlantic coastal waters and mouth of Delaware Bay. Gale
Watch in effect for the upper Bay as winds should be lighter.
Dangerous seas upward of 12 to 18 feet expected.

&&

.TIDES/COASTAL FLOODING...
Minor coastal flooding is forecast with the Friday morning high
tide, mainly for Atlantic, Cape May, and Cumberland Counties in
NJ and Sussex and Kent Counties in DE. Coastal Flood Advisories
remain in effect to highlight this threat. The Saturday high
tide could also experience minor coastal flooding, mainly near
southern Cape May County, southern coastal Delaware and Delaware
Bay, but confidence is lower on this at the moment and the
Advisory was not extended to Saturday just yet.

There is an increasing risk of moderate to potentially major
coastal flooding impacts beginning Sunday through Monday as a
strong coastal storm impacts the region. Guidance varies in
potential outcomes of this storm with regard to severity of
coastal flood impacts locally, however we are growing
increasingly concerned about the potentially significant impacts
from this storm along our coasts. At this time, the greatest
threat of impacts are anticipated to occur along the Atlantic
coasts of New Jersey and Delaware, and Delaware Bay. A Coastal
Flood Watch was issued to highlight this threat for the high
tides Sunday through Monday. With the most recent update,
Monmouth and Middlesex County in NJ were added to the Coastal
Flood Watch.

Significant beach erosion is possible along the entire New
Jersey Shore and Delaware beaches. Interests along the Atlantic
coast, Delaware Bay, back bays, and tidal waterways should
remain alert for forecast updates regarding this potentially
significant coastal flood event.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Freeze Warning from 11 PM this evening to 9 AM EDT Friday for
     PAZ054-055-061-062.
     Frost Advisory from 2 AM to 9 AM EDT Friday for PAZ060-101>106.
NJ...Coastal Flood Watch from Sunday afternoon through Monday
     evening for NJZ016.
     Coastal Flood Advisory until 3 PM EDT Friday for NJZ021>025.
     Coastal Flood Watch from Sunday morning through Monday evening
     for NJZ012>014-020>027.
     High Wind Watch from Sunday morning through late Sunday night
     for NJZ013-014-020-022>027.
     Freeze Warning from 11 PM this evening to 9 AM EDT Friday for
     NJZ001-007.
     Frost Advisory from 2 AM to 9 AM EDT Friday for NJZ008>010-015-
     017>022-027.
DE...Coastal Flood Watch from Sunday afternoon through Monday
     evening for DEZ001.
     Coastal Flood Advisory until 3 PM EDT Friday for DEZ002>004.
     Coastal Flood Watch from Sunday morning through Monday evening
     for DEZ002>004.
     High Wind Watch from Sunday morning through late Sunday night
     for DEZ003-004.
MD...None.
MARINE...Gale Watch from Saturday evening through Monday evening for
     ANZ430.
     Storm Watch from Saturday evening through Monday evening for
     ANZ431-450>455.
     Small Craft Advisory until midnight EDT tonight for ANZ451>453.
     Small Craft Advisory until 6 AM EDT Friday for ANZ454-455.

&&

$$

SYNOPSIS...Hoeflich/Staarmann
NEAR TERM...Johnson
SHORT TERM...Hoeflich/Staarmann
LONG TERM...Hoeflich/Staarmann
AVIATION...Hoeflich/Johnson
MARINE...Hoeflich/Johnson
TIDES/COASTAL FLOODING...PHI