Glasgow, Delaware 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

273
FXUS61 KPHI 081046
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
646 AM EDT Tue Apr 8 2025

.SYNOPSIS...
High pressure builds in today and Wednesday in the wake of a
strong cold front before shifting offshore Wednesday night. Low
pressure then arrives Thursday and Friday. This new low could
linger near the area through much of next weekend. High pressure
builds in for the back of the weekend and into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Strong cold front is currently sweeping across the region,
rapidly clearing the air as much colder and drier air builds in
behind it on gusty northwest winds. The day ahead looks dry for
the most part, though with upper level trough passing overhead
and northwesterly upslope flow, a few flurries could be had in
the Poconos through the day. Further south and east, some
stratocumulus likely develops by midday and lingers through the
afternoon thanks to the chilly air aloft and strong April
sunshine. This will also help mix some strong winds to the
surface, with some gusts up around 45 mph possible by midday and
this afternoon. Think it mostly stays short of wind advisory so
have not hoisted one, but looks pretty close. Otherwise, just a
chilly windy day with highs mostly in the 40s, 30s Poconos.

Tonight, cold advection begins to wane as winds begin to subside
while high pressure starts building overhead. However, the
damage will have already been done, and widespread sub-freezing
temperatures look likely. For most of the forecast area, the
frost/freeze season doesn`t being until April 11th, so no
headlines, but our central/southern Delmarva zones will be under
freeze warnings. If the temperature reaches 29 at PHL Airport as
forecast, it will be the latest temp that cold since 2018, when
it was 29 on April 11th. Otherwise, mostly clear tonight with
lows, as implied, mostly in the 20s, with near 30 warmer spots
south and coast and near 20 Poconos.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
Mid-week period is setting up to be a quiet one with high
pressure, though the Canadian airmass won`t begin to moderate
until the surface high moves offshore on Wednesday Night. Highs
on Wednesday will only get into the upper 40s/low 50s. With
clouds increasing on Wednesday Night and flow turning more
southerly, temperatures will be a bit warmer compared to
tonight, with lows in the upper 20s/low 30s north of I-78, with
mid to upper 30s south of the that line. Frost/Freeze program
for most areas north of southern Delmarva doesn`t start until
the next night, so do not anticipate any headlines, given
temperatures where the program is in effect should be high
enough to preclude any frost concerns.

Thursday begins a stretch of some unsettled days. Weak and
decaying low pressure moves into the Great Lakes, with a warm
front lifting through. The surface low will slowly occlude as a
new surface low begins to develop off to the south (which will
eventually bring some more widespread rain later in the week).
Lift will be aided by a shortwave swinging through. All of this
will result in some showers on Thursday, mainly west of
Philadelphia, though any rainfall will be light. Temperatures
could be cold enough in the Poconos to support some flakes at
onset, but would expect a quick changeover to rain as warm-air
advection continues. Outside of showers, clouds increase and it
should be a mostly cloudy to overcast day with temperatures
getting into the 50s, though still a few degrees below normal.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Weak low pressure moves into western New York/southern Ontario
on Thursday Night before occluding on Friday. This will result
in some showers on Thursday Night over the area. There could be
a brief break on Friday, but a new surface low looks to develop
over the Carolinas, lifting northward through the day on Friday.
This will bring another slug of rain through Friday Night as we
continue to make inroads on the ongoing drought. NBM
Probability of 1+ inch of rain for the end of the week is around
60-80% across the region. However, considerable uncertainty
remains in timing and evolution of the supporting upper level
trough and overall amplified pattern. If the trough hangs around
and closes off, unsettled weather likely continues through
Saturday. This solution is what most of the deterministic and
ensemble guidance has. A faster solution clears things out, as
upper level ridging will be on the heels of the departing
trough. Temperatures will be a few degrees below normal through
the end of the week and into the weekend with 50s for highs and
lows in the 40s.

At the very least, the back half of the weekend and first half
of next week looks quiet. Upper level ridging builds in,
ushering in temperatures back toward seasonal norms, with longer
range guidance showing some above normal temperatures possible
toward the middle of the week. Forecast looks dry overall with
high pressure at the surface sliding by to the south.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR with some scattered to broken clouds mainly above 3k
ft. West or Northwest winds 15 to 25 kt with gusts up to 35 kt
midday and afternoon. High confidence.

Tonight...VFR with slowly diminishing winds. High confidence.

Outlook...

Wednesday through Wednesday Night...VFR. No significant weather.

Thursday...Primarily VFR, though some MVFR conditons possible
with 40-60% chance of showers at KRDG/KABE.

Thursday Night through Friday...IFR conditions expected with
periods of rain moving through.

Friday Night through Saturday...sub-VFR conditions likely with
low clouds and scattered showers hanging around.

&&

.MARINE...
A cold front is crossing through the region early this morning,
bringing an abrupt shift to northwesterly winds. Winds will
also increase quickly, with gale force gusts expected to develop
near daybreak. Gale conditions are possible throughout the day
today, diminishing slowly tonight.

Outlook...

Wednesday through Thursday Night...No marine headlines expected.

Friday through Saturday...SCA conditions likely (60-70%) on the
ocean zones as seas build toward 5 to 6 feet. Wind gusts could
approach 25 kt at times.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...Freeze Warning from 11 PM this evening to 9 AM EDT Wednesday
     for DEZ002-003.
MD...Freeze Warning from 11 PM this evening to 9 AM EDT Wednesday
     for MDZ012-015-019-020.
MARINE...Gale Warning until 10 PM EDT this evening for ANZ430-431-
     450>455.

&&

$$

SYNOPSIS...Fitzsimmons/Gorse/Hoeflich/RCM
NEAR TERM...RCM
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Hoeflich/RCM
MARINE...Hoeflich/RCM