Long Valley, New Jersey Weather Forecast Discussion

018
FXUS61 KPHI 261033
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
633 AM EDT Fri Sep 26 2025
.SYNOPSIS...
A cold front passing through the area this morning is expected
to become stationary south of the area and linger into early-mid
week, allowing for a few waves of unsettled weather. Another
cold front will pass through the area mid-week, followed by
strong high pressure building southward in its wake.
&&
.NEAR TERM /THROUGH TONIGHT/...
Areas of dense fog will gradually mix out this morning.
Traveling will be more difficult with reduced visibilities this
morning.
For the rest of Friday, surface high pressure builds in from
the west, allowing drier air to filter into the region. There
will still be an upper level trough pivoting across the Mid
Atlantic, but the best forcing will remain offshore where the
frontal boundary has stalled. Can`t fully rule out a few showers
along the southern NJ and southern DE coast, especially in the
morning, but the region should be mostly dry with some high
clouds around. Otherwise, afternoon temperatures will warm into
the upper 70s to low 80s.
Tonight, mostly dry conditions with calm winds, but skies won`t
be fully clear to allow for runaway radiational cooling. The
stalled boundary remains offshore, but can`t rule out a stray
shower overnight across southern DE. Temperatures will cool off
into the mid 50s to mid 60s. Some patchy shallow fog possible,
mainly across the north and west where skies may be most clear.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A weak upper-trough will be centered over portions of the
Southeast Saturday morning, gradually cutting off with little
movement through Sunday night. This will lead to modestly
enhanced southwesterly flow aloft across the area throughout the
period. At the surface, a stationary front will remain draped
across portions of the Mid- Atlantic south of the forecast area.
This overall pattern will favor unsettled weather with waves of
showers possible. Right now, it appears that the greatest
chance for showers across the entire area will be Saturday
night, with PoPs at least 30% across the entire area. Likely
PoPs (60-80%) are expected across portions of the Delmarva and
far southern NJ. Modest elevated instability could lead to an
embedded storm or two, but severe weather is not anticipated.
Rainfall amounts do not look particularly impressive at this
time, with most locations seeing 0.5" or less. Lingering showers
are possible into the day Sunday, especially across
southeastern PA, southern NJ, and the Delmarva. Sunday night
should be dry for most.
Temperatures on Saturday look to be in the mid-upper 70s across
the area. Lows Saturday night look to range from the upper 50s
across the higher elevations of eastern PA and far northern NJ
to the low- mid 60s elsewhere. Temperatures Sunday will depend
on how many showers linger, and to what extent cloud cover
clears out. For now, most locations look to be in the mid 70s,
but a few locations could approach 80 if sufficient drying and
clearing occurs. Lows Sunday night across much of eastern PA and
northern NJ look to be in the mid-upper 50s, with low 60s
elsewhere.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The long term forecast remains highly uncertain, in large part
due to Tropical Storm Humberto and another area of interest
currently located north of the Greater Antilles that is expected
to develop into a tropical cyclone as it tracks generally
northwestward.The exact evolution of the upper air and surface
pattern is also inherently uncertain, but in general the cutoff
low over the Southeast is expected to remain in place through
mid-week with weak flow across the area. At the surface, a cold
front with strong high pressure in its wake will eventually
shift southward into the region. The extent of this high and the
rate at which is shifts into the area will be consequential in
forecasting the evolution of the tropical cyclones, and how
close they may ultimately get to the area.
For now, confidence has increased that this high will keep
direct impacts from the tropical systems to the south of the
area. However, it must be stressed that this is a complex
scenario with what is ultimately expected to be two tropical
cyclones in close proximity to each other, and their future
interactions with each other and the larger scale surface and
upper patterns remains uncertain. With all of this being said,
have chance PoPs for rain Monday and Tuesday primarily south of
I-78. With high pressure eventually settling into the area,
Wednesday and Thursday appear more likely than not to be dry,
and do not have mentionable PoPs at this time.
Temperatures look to be seasonable Monday and Tuesday, with
below average temperatures arriving behind the cold front
Wednesday or Thursday.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas...
Friday...Some lingering fog past 12Z, mostly for ABE/RDG/TTN.
After that however, VFR is expected to return by mid- morning
and remain for the remainder of the day. West to Northwest winds
will increase to around 10 knots by afternoon. Medium confid.
Outlook...
Friday night... Mainly VFR conditions. Some patchy shallow fog
possible for RDG/ABE. Winds light and variable. Medium confid.
Outlook...
Saturday...Primarily VFR. Brief periods of sub-VFR conditions
are possible late in showers.
Saturday night...Sub-VFR conditions possible in showers.
Sunday through Sunday night...Primarily VFR. Brief periods of
sub- VFR conditions are possible in lingering showers.
Monday through Tuesday...Periods of sub-VFR conditions cannot
be ruled out with rain possible at times.
&&
.MARINE...
Sub-SCA conditions through Friday night. West winds around 10
kts or less, shifting more southerly in the afternoon before
turning north Friday night. Seas 3 to 4 feet diminish to 2 to 3
feet.
Outlook...
Saturday through Sunday...No marine headlines expected with
winds generally below 25 kt and seas below 5 feet.
Monday through Tuesday...Marine headlines will likely be needed
as winds and seas both increase. For now, wave heights look to
be the primary concern, potentially well in excess of 5 feet.
Winds could exceed 25 kt as well, particularly Monday night into
Tuesday.
Rip Currents...
For Today...Westerly wind 5-10 mph becoming southerly in the
afternoon. Breaking wave heights generally 1-2 feet. While there
will be swell from offshore storms, it appears that it will be
weak and have a short period. Given the offshore to shore-
parallel flow and low breaking wave heights, have opted for a
LOW risk for the development of dangerous rip currents at all
beaches.
For Saturday...Northeasterly wind 5-10 mph becoming easterly in
the afternoon. Breaking wave heights generally 1-2 feet. Swell
from offshore storms remains insignificant in height and period.
Given these factors, have opted to maintain a LOW risk for the
development of dangerous rip currents at all beaches.
For specific beach forecasts, visit weather.gov/beach/phi
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Dense Fog Advisory until 9 AM EDT this morning for PAZ060>062-
     101>106.
NJ...Dense Fog Advisory until 9 AM EDT this morning for NJZ015.
DE...None.
MD...None.
MARINE...None.
&&
$$
SYNOPSIS...Cooper
NEAR TERM...MJL
SHORT TERM...Cooper
LONG TERM...Cooper
AVIATION...Cooper/MJL
MARINE...Cooper/MJL

NWS PHI Office Area Forecast Discussion