661
FXUS61 KPHI 040836
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
336 AM EST Wed Nov 4 2026

.WHAT HAS CHANGED...
Aviation section updated with 06Z TAFs.

&&

.KEY MESSAGES...
1. Patchy fog possible early this morning. No significant
weather otherwise through Wednesday.

2. A slow moving cold front approaches the area Thursday night into
Friday bringing the potential for heavy rain to portions of the area.

&&

.DISCUSSION...
KEY MESSAGE 1...Patchy fog possible early this morning. No
significant weather otherwise through Wednesday.

An expansive area of high pressure offshore is in control, resulting
in warm south/southwesterly flow and tranquil weather. A stretch of
nice mid-Fall days will continue through the middle of the week.
With some weak moisture advection, mostly clear skies, and light
winds tonight, some patchy fog may develop early this morning.
Not expecting widespread dense fog, however, but some areas
could see some lower visibility for the morning commute. Any fog
dissipates by 9-10 AM and it should be a nice Wednesday with
warm temperatures in the 70s yet again.


KEY MESSAGE 2...A slow moving cold front approaches the area
Thursday night into Friday bringing the potential for heavy rain to
portions of the area.

Upper level ridging will finally begin to break down by Thursday as
a potent upper trough over the central CONUS cuts off and lifts
northeast into the Great Lakes region by Friday. This upper level
low is then forecast to slowly move east toward New England over the
weekend. At the surface, low pressure over the Central Plains will
lift north into the northern Great Lakes by Wednesday and up into
Quebec/Ontario on Thursday. Its associated cold front will trail
back to the southwest but will begin to slow down in forward
progression as it tracks toward the region before eventually
stalling somewhere over/offshore of the Mid-Atlantic late Thursday.
The biggest question that remains at this time is where exactly and
in what orientation does the front stall/wash out, as this will play
a major factor on how things pan out later Thursday and Friday.
Given the latest RRFS and ensemble guidance it is becoming
increasingly likely that the front will stall out within close
vicinity to our area. Guidance is then keen on developing a surface
low along the boundary late Thursday night and into Friday while
tracking northeast along the stalled boundary before lifting up into
New England on Saturday and pulling the front offshore.

All in all, this will yield the potential for some showers and light
rain to begin on Thursday for western areas as the front approaches.
But as the front weakens, the forcing will too, meaning that many
areas will stay mainly dry on Thursday as PoPs are generally less
than 30% along and southeast of the I-95 corridor. This changes by
Thursday night and into Friday, as a higher plume of PWATs will
surge northward upwards of 1.5-1.7 inches, which would push close to
the climatological max for early November. While not currently
outlooked by WPC in the Excessive Rainfall Outlook, it is in the
realm of possibility that areas of heavy rain may occur from time to
time late Thursday night into Friday. The greatest potential of this
threat and where there may be a localized maxima of higher QPF is
targeted to be south and east of the I-95 corridor at this point in
time. However, it should be noted that this is highly uncertain and
dependent on the placement of the stalled front. To summarize, a
slower front will yield more rainfall across the region, in
comparison to a faster front which will yield less rainfall across
the region.

Rain chances should then decrease heading into the weekend as
surface high pressure attempts to build in from the west. However,
as the upper low meanders across the Northeast, this is highly
dependent on how lobes of shortwave energy evolve. Thus, while it
has trended drier over the weekend, there is quite a bit of
uncertainty. The takeaway message here is that the weekend may not
be fully dry and could remain somewhat unsettled into early next
week with some diurnal opportunities for showers.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Early this morning (through 12Z)...Mostly VFR, but areas of fog
are likely to develop early this morning. 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/KTTN. Went ahead
and included KPNE/KPHL. Confidence remains low in where exactly
fog develops. 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.

Wednesday night...VFR. A slight chance of showers near KRDG.
Patchy fog possible. Winds generally light and variable.
Moderate confidence.


Outlook...

Thursday through Saturday...Periods of sub-VFR conditions likely,
especially Thursday night into Friday. Periods of rain expected with
a slight chance of a thunderstorm.

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

&&

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

Outlook...

Thursday...No marine headlines expected. Winds will generally
remain less than 20 kt with seas of 2-4 feet. Fair weather.

Thursday night through Sunday...Periods of SCA conditions possible.
While winds will largely remain less than 25 kt, seas are expected
to range between 3-5 feet. Periods of rain likely through Saturday.

&&

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

&&

$$

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