378
FXUS61 KPHI 272308
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
708 PM EDT Thu Mar 27 2025

.SYNOPSIS...
High pressure will shift offshore and remain in the vicinity of
Bermuda through the weekend. A weak warm front will lift north
across the region tonight before a more potent warm front pushes
across the area Friday night, resulting in a much warmer
Saturday. The front will sag back south on Saturday night
before lifting back north of the area on Sunday. A low pressure
system will approach the region on Monday with a cold frontal
passage on Monday night. High pressure will then return for
Tuesday and Wednesday.

&&

.NEAR TERM /THROUGH FRIDAY/...
Forecast is on track this evening. Only some minor tweaks made
but nothing of significance.

Initial relatively weak warm front will cross the region
tonight, resulting in some increase in clouds for a time
especially across northern regions, where a stray snow shower
can`t be ruled out, along with winds becoming more southerly.
Lows will generally be milder than last night, but still near or
slightly below normal, with low-mid 30s common. Some cold spots
might nudge into the 20s.

Any morning sun tomorrow should fade behind increasing clouds as
a stronger warm front approaches from the west. Guidance is not
in great agreement regarding arrival of any showers with this
system, so have pops gradually increasing to slight chance as we
head through the afternoon. Dry air at the surface may initially
slow this down, but the strong warm advection aloft may end up
negating it. Either way, most likely any showers arrive closer
to the evening rush or later. That said, the initial push of
milder air behind tonight`s weak front should still help brings
temps into the 60s for most of the region despite the increasing
clouds.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
The short term period will feature an early-summer like weather
pattern as a very warm airmass develops over the area.

The upper trough that has been over the Northeast US the last couple
days pulls away on Friday. Flow aloft will become zonal through
Saturday as an upper trough moves into the Central US allowing the
ridge to amplify over the eastern US on Sunday. At the surface, high
pressure will be located over the western Atlantic in the vicinity
of Bermuda through the weekend. A warm front will lift north of the
area on Friday night allowing the entire area to be in the warm
sector on Saturday. The front will sag back south on Saturday night
across portions of the area, but this appears to be short-lived as
the front lifts clear of the area again on Sunday.

So what does this mean? For Friday night, some energy aloft
will be accompanied with the passing warm front. As forcing for
ascent increases, should see a band of showers develop, so have
kept 20-40% PoPs across the area. QPF will be minimal however,
perhaps a few hundredths of an inch at most. Lows will be mild
ranging from the mid 40s to mid 50s.

For Saturday, the region will be located in the warm sector, so
expecting a very mild start to the weekend. Despite some clouds
around, strong south-southwesterly flow will allow afternoon highs
to soar well into the 70s, and perhaps surpassing the 80 degree mark
in some spots with 60s in the Poconos and along the coast. Should
fall well short of any records, but this does look to be our warmest
day of the season thus far. Latest guidance suggests that the front
will sag back south on Saturday night across northern portions of
the area. This will result in another chance for showers especially
north of Philly with temperatures remaining mild in the upper 40s to
upper 50s. The front should gradually make its way back north again
on Sunday. So while temperatures are not expected to be quite as
warm compared to Saturday thanks to more cloud cover and showers
around, still expecting highs in the 60s and 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Upper trough will begin to approach the region on Sunday night as
surface low pressure tracks across the southern Great Lakes and into
southern Quebec on Monday. A cold front will trail back to the west
and cross through the area late in the day on Monday into Monday
night. Showers and isolated thunderstorms will be accompanied with
the front as it tracks through, but it is quite too early for any
specifics. Depending on the amount of destabilization that occurs
ahead of the front in combination with modest flow aloft, this may
support a few strong to severe storms to occur with the front. This
is supported by the CSU-MLP guidance and by the Storm Prediction
Center which has portions of the region in the Severe Weather
Outlook on Monday.

Behind the frontal passage, we`ll start to see some improvement as
Canadian high pressure returns for Tuesday and Wednesday. Another
disturbance will approach from the west late in the day on
Wednesday, but current guidance suggests that any precipitation
should hold off until at least Wednesday night and potentially
into Thursday.

In terms of temperatures, another warm day is expected on Monday
with temperatures roughly 15-20 degrees above normal. Once the front
passes through, we`ll see temperatures return to more seasonable
levels for Tuesday and Wednesday before warming up again with
the next system for Thursday.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...VFR. SW winds around 5-10 kts. Mid and high clouds
filter in after midnight. High confidence.

Friday...VFR. Southwesterly winds around 5-10 kt. Cloud bases
lower through the day with some scattered light showers moving
in after 18z. Any showers that move directly over a terminal
should not drop conditions below VFR though. Moderate confidence
overall.

Friday Night...Primarily VFR. Some scattered light showers
around which could drop conditions to MVFR briefly, but
expecting a majority, if not all of the period, to stay VFR.
CIGs generally around 4000 feet or higher.

Outlook...

Saturday through Saturday night...Mainly VFR expected. Sub- VFR
conditions possible on Saturday night in association with light
rain showers. Gusty winds up to 25 kt possible on Saturday.

Sunday through Monday...Mainly VFR expected on Sunday. Sub-VFR
conditions possible thereafter. Rain showers becoming more likely
by Sunday night with a chance of showers and thunderstorms on Monday.

Tuesday...VFR conditions with no significant weather expected.

&&

.MARINE...
High pressure will be in control. Sub-Small Craft Advisory
conditions on tap through Friday. Southwesterly winds around
10-20 kt. Seas 2 to 3 feet.

Outlook...

Friday night through Saturday...SCA conditions possible on the
Atlantic coastal waters due to seas around 4-6 feet.

Saturday night through Sunday...Lingering SCA conditions possible
early, but overall no marine headlines expected.

Sunday night through Tuesday...SCA conditions probable on the
Atlantic coastal waters due to wind gusts near 25 kt and seas
around 4-6 feet.

&&

.FIRE WEATHER...
Fire weather concerns diminish for Friday and the weekend.
Humidity will rise with minimum RHs 35 percent or higher Friday
and Saturday, going even higher Sunday and Monday. A wetting
rain is also possible Sunday night and Monday. This section will
be removed in subsequent updates.

&&

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

&&

$$

SYNOPSIS...DeSilva/RCM
NEAR TERM...Hoeflich/RCM
SHORT TERM...AKL/DeSilva
LONG TERM...AKL/DeSilva
AVIATION...AKL/Guzzo/Hoeflich
MARINE...AKL/RCM
FIRE WEATHER...Hoeflich