021
FXUS61 KPHI 200540
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1240 AM EST Thu Nov 20 2025

.SYNOPSIS...
High pressure builds in tonight and Thursday. A weak cold front
moves through during Friday, which then stalls near Delmarva on
westward. Low pressure along this front tracks near our area
Friday night into Saturday, then high pressure builds in for
Sunday. A cold front crosses our area later Monday followed by
high pressure gradually arriving during Tuesday. More unsettled
for the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Flow aloft will be largely zonal through tonight, becoming more
northwesterly with time as an upper-low tracks southeastward
across northern portions of Quebec. At the surface, high
pressure will remain in control across the Mid-Atlantic and New
England.

This morning will be fairly chilly, with temperatures below
freezing across most of eastern PA and NJ away from the urban
corridor and the coastal plain. For the Delmarva, the urban
corridor, and the coastal plain, temperatures will be in the mid
30s to near 40. Light winds and residual ground moisture from
the recent rainfall has allowed some patchy fog to develop.
Areas of patchy fog will remain possible until a little after
sunrise when temperatures start to warm up. Otherwise, it will
be partly to mostly cloudy.

Mostly cloudy to overcast skies will continue across most of
the area through the day today. Far northern portions of the
area may see some clearing during the afternoon hours. High
temperatures look to range from the mid-upper 40s northwest of
I-95 to near 50 southeast. No precipitation is expected. Winds
will be quite light today, with an easterly direction being
favored.

Tonight, overcast skies and light winds will continue. In fact,
some lower level clouds are expected to filter in to most of
the area. Overnight lows will be a bit warmer, with only the
higher elevations getting to freezing. Temps in the mid 30s to
near 40 are expected elsewhere.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
High pressure will slide east off the coast Thursday night, with
warm advection bringing clouds back to the region. Lows in the 30s
north, 40s central and south.

Wave of low pressure moving east toward the region will keep it
pretty cloudy on Friday. However, warm advection precip may yet hold
off until evening, but have slight chance to low chance POPs late in
the day. Despite clouds, expect highs to rise back into the 50s for
most of the area, except 40s Poconos and near 60 southern Delaware.

Most guidance has rain, albeit light, spreading eastward across the
region by Friday night as the aforementioned weak wave moves almost
straight toward us. An approaching cold front from the northwest and
associated upper trough may try to divert the system more across our
southern zones, while a later arrival of said front/shortwave may
cause it to veer further north, but for now have likely to
categorical POPs most of the CWA except far north. Lows 30s Poconos
but 40s pretty much everywhere else... near 50 immediate coast.

System pulls eastward out to sea on Saturday, with any rain early
ending and clouds breaking for some sun toward evening as a cold
front shifts southward across the region. That said, the wind flow
doesn`t look especially strong so the low level moisture may
struggle to be eroded away. Highs similar to Friday.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
High pressure builds eastward into the region Saturday night and
mostly remains in control through Monday night as it slowly builds
eastward, eventually passing off the New England/Mid-Atlantic coast.
A weak front might spark a few showers Sunday evening, but odds look
pretty low on this.  Cold advection push will be noticeable Saturday
night and Sunday, with lows in the 20s and low 30s, followed by
highs in the 40s to low 50s. Temps moderate slowly thereafter, with
lows mostly above freezing (but still 30s) on Sunday night and highs
mostly in the 50s Monday, near 60 Delmarva. A still milder night is
likely Monday night just ahead of the next system, with lows in the
mid 30s to low 40s.

Some guidance is faster than others as far as spreading rain into
the region with the next system, which will be a low pressure
heading northeast through the Mid-west towards the Great Lakes
Tuesday and Wednesday, but most guidance has rain across the region
Tuesday night. Highs on Tuesday may end up a smidge warmer than
Monday if the rain is delayed, but a milder night is likely with the
rain on Tuesday night, with lows mostly 40s, near 50 coast and
southern Delaware.

Guidance is also a little uncertain on when rain ends Wednesday, but
most models have it out of here by day`s end. A mild day looks
likely as there is no initial push of cool air behind Tuesday
night`s system, with highs likely to be near or above 60 in much of
the region.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12Z...Primarily VFR. Brief periods of visibility
restrictions are possible away from the I-95 terminals in patchy
areas of fog. Light and variable wind with periods of calm
likely. High confidence.

Today...VFR. BKN mid and high clouds. Light wind increasing
slightly to around 5 kt in the afternoon with an easterly
direction favored. High confidence.

Tonight...VFR to start, with most terminals seeing a transition
to MVFR ceilings during the overnight hours. Wind light and
variable with periods of calm likely. High confidence.

Outlook...

Friday...VFR likely most of day, but sub- VFR possible with
rain possibly arriving late.

Friday night...Sub-VFR with rain likely.

Saturday...Starting sub-VFR with lingering rain possible, then VFR
returning.

Saturday night through Monday...VFR likely.

&&

.MARINE...
No marine headlines will be necessary through tonight with wind
initially northerly at 10-15 kt with seas 2-4 feet. Later today
and into tonight, winds will shift to more of an easterly
direction but decrease even further to 5-10 kt with seas 2-3
feet.

Outlook...

Friday through Friday night...Sub-SCA likely. Rain likely
Friday night.

Saturday...SCA possible with gusts up to around 25 kts.

Saturday night through Monday...Sub-SCA conditions likely.

&&

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

&&

$$

SYNOPSIS...Gorse
NEAR TERM...Cooper
SHORT TERM...RCM
LONG TERM...RCM
AVIATION...Cooper/DeSilva/MJL/RCM
MARINE...Cooper/DeSilva/MJL/RCM