012
FXUS61 KPHI 050935
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
435 AM EST Wed Feb 5 2025

.SYNOPSIS...
High pressure Wednesday will be followed by a low pressure system
and its associated fronts late Wednesday through Thursday night,
bringing a slew of wintry precipitation. After that, high pressure
looks to briefly return for the end of the week before our active
pattern returns and the next disturbance approaches for the weekend.
Another storm system may then affect our region toward the middle of
next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The near term forecast remains on track as mid-level clouds continue
to overspread the region early this morning, resulting in mainly
overcast skies. Temperatures are mainly in the upper 20s to low 30s
across the area and may not cool too much further as the increased
cloud cover and continued breeze will limit radiational cooling
somewhat. Some light radar returns have been persistent over
Delmarva this morning. However, with forecast soundings showing a
dry layer beneath the saturated DGZ, little, if any, precipitation
looks to be making it to the ground.

Heading into the daytime hours for today, mostly cloudy skies are
expected to persist as mid and upper level flow remains
northwesterly. At the surface, weak high pressure will become
centered over the region before moving offshore late this afternoon
into the evening. The presence of this high should maintain the dry,
subsident layer in the low-levels, keeping the area mainly dry
overall. A few flurries can`t be completely ruled out, again most
likely in Delmarva. With the center of the high transiting through
the region, winds will be light and variable for much of the day,
and particularly this afternoon. High temps are expected to be
mainly in the 30s, with some mid-upper 20s in the southern Poconos.
As the high exits this region late this afternoon, some light snow
or sleet from the incoming low pressures system may begin to move
into Delmarva. However, the bulk of the precipitation looks to hold
off until later on.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
A smorgasbord of wintry precip will be in store for us
Wednesday night into Thursday morning, possible impacting the
Thursday morning commute. Much of the region is expected to see
nearly every wintry precip type through this period - snow,
sleet, and freezing rain, all mixed and matched. The Winter
Weather Advisory was expanded to include all inland zones. With
onshore flow, the coastal strip is most likely to see warming
occur first. While they may very well see some wintry precip at
first, the threat of impacts is much less as they will likely
warm and change over to rain rather soon after, thus they were
not included in the advisory at this time.

Cold air in place from earlier in the day Wednesday interacts with
low pressure moving into the region from the west-southwest, which
then redevelops over our region as it jumps the mountains and then
heads out to sea. Cold high pressure centered just to our north
Wednesday evening will be retreating steadily to the east into the
ocean, allowing southeasterly winds to start bringing milder air
inland, but the process will be slow. The result will be a wintry
mess as mentioned prior.

The onset of precip will likely begin sometime Wednesday evening
across the Delmarva and extreme southern NJ. As the low strengthens,
precip will coalesce around an FGEN band that will begin across
the Delmarva. If precip begins early enough, we could see a
period of snow and sleet impact the latter half of the Wednesday
evening commute across the Delmarva and extreme southern NJ. As
the system continues to organize, wintry precip will begin to
fill in from south to north across the region through the
nighttime hours. Wintry precip will likely begin for the
southern half of the region (Philly and south) before midnight
with wintry precip overspreading into the northern half sometime
after midnight or so. Most places will see snow to start off
and then switch over to a wintry mix of sleet and freezing rain
before sunrise Thursday morning. As a result, the Thursday
morning commute could be rather icy for many locations. After
daybreak, warm air advection will gradually warm things along,
changing most locations over to rain through the morning and
into the early afternoon. The Poconos could hold on longer to
some sleet and freezing rain during the day Thursday, but precip
will begin to taper off by the afternoon for everyone.
Temperatures will warm to the upper 30s to around 50 for the
afternoon.

Temperatures look to stay largely in the upper 30s to mid 40s for
much of the evening before a reinforcing dry cold front moves in
early Friday morning to cool temperatures down into the low 30s to
low 40s. Aside from the higher elevations reaching close to
freezing, much of the region is expected to remain above freezing
for the Thursday night lows, so refreeze is not as widespread of a
concern.

Friday, with high pressure building back in behind the front, should
feature plenty of sunshine and seasonable to slightly above normal
temps, with highs in the 30s north, 40s for the bulk of the area. It
will be breezy, so that`ll make it feel a bit more seasonable.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
An active weather pattern will continue across the area this weekend
and continue through the middle of next week, with the potential for
multiple impactful storm systems.

Friday evening, northwesterly mid-level flow will be in place across
the area, with surface high pressure moving eastward from the Ohio
Valley into the Mid-Atlantic. Subtle height rises will occur through
much of the day Saturday, as our next shortwave and associated
surface cyclone approaches the area. As this system approaches the
area, associated ascent will lead to the development of widespread
precipitation by Saturday evening. Cold temperatures will be in
place as the precipitation shield arrives, so initial precipitation
type across the area should be of the wintry variety (mostly snow
and maybe some sleet). However, the current expected track of the
surface cyclone to the north of the area will lead to strong warm
air advection throughout Saturday night and continuing until the
trailing cold front passes through the area on Sunday. As a result,
most locations would likely experience increasingly mixed
precipitation types, and eventually change to rain. This system will
exit the area on Sunday, leaving breezy northwesterly surface winds
in its wake.

Monday looks tranquil across the area with temperatures near to
slightly below normal. However, with the active pattern in place,
another storm system will already be on approach to the area. Models
are in fairly good agreement this afternoon that another shortwave
trough will approach the area on Tuesday. An accompanying surface
cyclone, possibly a coastal low, could bring impactful wintry
weather to the area. While this will certainly bear watching as it
gets closer in time, it is too early to speculate on any
specifics.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Early this morning...VFR with increasing clouds overnight.
Northwesterly winds 5-10 knots, becoming light and variable to
locally calm at some terminals. Moderate confidence.

Today...VFR with gradually lowering ceilings. North-northwest winds
5-10 knots diminishing in the afternoon and becoming light and
variable. Moderate confidence.

Tonight...VFR conditions to start but IFR conditions developing from
south to north as a mix of precipitation moves in. Dominate
precipitation type is expected to begin as snow, before gradually
changing to sleet and then freezing rain. However, multiple
precipitation types occuring simultaneously is likely. Precipitation
onset is likely to be between 03-05Z but MVFR and IFR restrictions
look to hold off until the 06-09z timeframe when heavier
precipitation moves in. Winds becoming southeasterly around 5-10
kts. Moderate confidence in overall pattern, low confidence in
timing of precipitation type and category changes.

Outlook...

Thursday through Thursday night...IFR conditions likely.
A mixed bag of precipitation Thursday morning will gradually switch
to rain by the afternoon, possibly followed by lingering low clouds,
drizzle and mist Thursday night.

Friday...VFR. No significant weather expected.

Saturday...Sub-VFR conditions probable with periods of
rain/snow.

Sunday...Sub-VFR conditions possible to start as rain/snow ends
before improving to VFR later in the day.

&&

.MARINE...
Conditions are anticipated to remain below Small Craft Advisory
criteria through tonight. Northwesterly winds continue to diminish
from south to north early this morning, and seas are below 5 feet.
The winds today will be light from the northwest and north, before
becoming more from the northeast or east later in the day. Tonight,
winds become east to southeasterly and begin to increase once again
to around 10-15 knots with gusts up to 20 knots. Rain/snow/sleet
precipitation mix progresses northward through the night. Seas
remain around 2-4 feet.

Outlook...

Thursday through Friday...SCA conditions probable due to wind gusts
up to 25 kt and seas around 5 feet. Periods of rain on Thursday.

Friday night through Saturday...No marine headlines expected.
Rain/snow mix on Saturday.

Sunday...SCA conditions possible with wind gusts up to 25 kts
and seas building to 3-5 feet. Lingering rain/snow possible in
the morning.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 11 PM this evening to 1 PM EST
     Thursday for PAZ060>062-101>103-105.
     Winter Weather Advisory from 11 PM this evening to 10 AM EST
     Thursday for PAZ070-071-104-106.
     Winter Weather Advisory from 11 PM this evening to 3 PM EST
     Thursday for PAZ054-055.
NJ...Winter Weather Advisory from 7 PM this evening to 8 AM EST
     Thursday for NJZ016-021>023.
     Winter Weather Advisory from 11 PM this evening to 1 PM EST
     Thursday for NJZ001-007>009.
     Winter Weather Advisory from 11 PM this evening to 10 AM EST
     Thursday for NJZ010-012-013-015-017>020-027.
DE...Winter Weather Advisory from 7 PM this evening to 8 AM EST
     Thursday for DEZ001>003.
MD...Winter Weather Advisory from 7 PM this evening to 8 AM EST
     Thursday for MDZ012-015-019-020.
MARINE...None.

&&

$$

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