502
FXUS61 KPHI 031730
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1230 PM EST Tue Nov 3 2026

.WHAT HAS CHANGED...
Updated aviation discussion for 18z TAFs.

&&

.KEY MESSAGES...
1. Potential fog development tonight, but otherwise, generally
tranquil weather prevails through the middle of the week.

2. The next chance for rain returns late this week and into the
weekend.

&&

.DISCUSSION...
KEY MESSAGE 1. Potential fog development tonight, but otherwise, generally
tranquil weather prevails through the middle of the week.

High pressure will remain in place within the vicinity of our
area through the middle of the week. Dry weather is expected to
continue through Wednesday amid warming temperatures each day.

Scattered to broken high cloud cover will persist through the
middle of the week despite surface high pressure. Temperatures
are expected to increase back to above normal values, warming
each day through Wednesday. High temperatures look to be in the
upper 60s to low 70s Tuesday, and in the low to mid 70s
Wednesday. Overnights will becoming increasingly milder (no
frost/freeze potential). Dry weather is expected to persist
through Wednesday.

There is potential for areas of fog development tonight.
Dewpoints will also be on the rise each day. Given mostly clear
skies, light winds, and long nights, we anticipate some fog
development across the area during the overnight periods.
Light southerly flow will promote dewpoint advection and the
solar insolation is relatively weak until closer to midday,
which will limit mixing earlier in the morning.


KEY MESSAGE 2...The next chance for rain returns late this week and
into the weekend.

The ridging that has be in place across the area for the past
several days will finally begin to break down by Wednesday night
into Thursday as a potent upper trough over central CONUS cuts off
and lifts northeastward into portions of the Great Lakes and
southern Canada by the end of the week. As this occurs, broad
troughing is expected to take shape across the eastern CONUS as a
few lobes of upper level energy will pivot through the region
Thursday and over the weekend. At the surface, low pressure over the
Midwest is forecast to track northeast into Canada as it weakens
into Thursday with a trailing cold front back to the southwest.
Latest guidance shows this frontal boundary washing out and
stalling across the region Thursday night. General QPF guidance
shows around 0.25 to 0.35 inches through daybreak Friday. After
this time, there is still considerable uncertainty as to how
this system will evolve to impact our local area.

Heading into Friday, while uncertainty remains, the latest
guidance shows a polar trough phasing with a lobe of upper level
energy, resulting in a rather poignant troughing patter across
the eastern US. Guidance varies on the exact evolution of this
trough through Friday, but several models show it digging before
ultimately becoming a cut-off low across the Mid Atlantic or
Northeastern states by Friday night. In the process, a surface
low may form along the previously stalled boundary, beginning
across VA/NC and trekking along the front into coastal New
England. PWAT values look to creep up into the 1.50-1.75" range,
which would push into the climatological maximum for this time
of year. QPF forecasts this far out are also pointing out the
potential for a corridor of heavy rainfall of a few inches or
more, though the exact placement of where the heaviest rain will
occur remains highly uncertain at this time.

Heading into this weekend, surface high pressure attempts to
build in from the west, but will struggle to gain full control
with broad upper level troughing and a cut-off low pattern
overhead. Any upper level pattern like this will be highly
dependent on how these cut-off lows and their lobes of shortwave
energy evolve, a set-up which always bring more uncertainty
than usual to the forecast. The takeaway message here is that
the weekend may not be fully dry and could remain somewhat
unsettled.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of Today...VFR. South/southwest winds around 5 to 10 kt.

Tonight...Primarily VFR through most of tonight but areas of fog
likely develop. High resolution guidance has fog mainly focused
around the coastal plain of New Jersey and the Lehigh Valley.
This could result in MVFR/IFR restrictions after 09z for
KRDG/KABE/KACY/KMIV. Given the more rural microclimate of KTTN,
a group of MVFR restrictions was added. Confidence remains low
in where exactly fog develops and restrictions could extend all
the way down into Philadelphia and Wilmington. Winds generally
light and variable, though a southerly direction may be favored
at times.

Wednesday...Fog mixes out by 13z-14z with VFR conditions
expected after. South/southwest winds 5 to 10 kt. High
confidence.


Outlook...

Wednesday night...VFR. No significant weather expected.

Thursday through Saturday...Sub-VFR conditions probable. Rain
chances daily with a slight chance of thunderstorms on Thursday.

&&

.MARINE...
Tranquil conditions expected on the waters through tomorrow with
southerly winds around 10 kt and seas 1 to 2 feet.

Outlook...

Wednesday night...No marine headlines expected. South winds
generally around 5-15 kt with seas around 2-3 feet. Fair
weather.

Thursday through Saturday...SCA conditions possible. While winds and
gusts are expected to remain below 25 kt, seas around 3-5 feet are
possible. Daily showers possible.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

DISCUSSION...MJL/WFO PHI
AVIATION...Hoeflich/MJL
MARINE...MJL