Glasgow, Delaware 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

226
FXUS61 KPHI 150800
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
400 AM EDT Tue Apr 15 2025

.SYNOPSIS...
A cold front will move through the region this morning,
followed by a strong upper level disturbance this afternoon.
High pressure builds in from the west on Wednesday and then
moves offshore on Friday. A cold front passes through the region
on Saturday. High pressure returns for the start of the new
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
An initial cold front will push through this morning with a
batch of showers expected to develop along it, mainly across the
Delmarva and southern NJ. Total QPF from this first round of
showers around a tenth of an inch or less.

Through the rest of the day Tuesday, we will be under the
influence of a cut off low centered over southern Quebec and
Ontario. The resultant cyclonic flow over the region along with
sufficient moisture will keep things more unsettled across the
region this afternoon. A rather strong upper level trough
embedded in the upper low will pivot across the region this
afternoon, providing broad scale lift across the region to
produce some rather strong showers. Model forecast soundings
show dew points lowering during the day as mixing deepens and
this leads to an inverted-V profile (steep low- level lapse
rates). This atmospheric setup will allow for a few things to
occur... 1) A well-mixed boundary layer will allow wind gusts
across the region to reach into the 30-45 mph range... 2) Any
stronger showers that develop will be capable of producing
stronger wind gusts locally given the transporting of stronger
winds aloft down to the surface along with some evaporational
cooling taking place within the downdraft... 3) Any strong
showers or convective cells could be capable of producing some
small hail/graupel given some instability combined with
favorable low and mid level lapse rates along with lower
freezing levels. High temperatures on Tuesday will be in the
upper 50s to mid 60s.

Showers will dissipate in the evening as the upper level
embedded trough shifts east along the the upper low. Breezy west
winds ease off slightly Tuesday night, though gusts will still
be around 20-25 mph. Overnight lows will be in the mid 30s to
low 40s (low 30s for the Poconos).

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Surface high pressure builds in from the north and west, with
the center of the high over the Great Lakes and Ohio Valley, and
extending down to the Gulf Coast states on Wednesday. The high
gradually builds east Wednesday night, and will slide offshore
on Thursday, and establishes itself offshore Thursday night.

An upper level trough will be over the Northeast on Wednesday,
and a tight pressure gradient will form between low pressure
over eastern Canada and high pressure to the west. Gusty west to
northwest winds will develop, generally ranging from 15 to 20
mph with 30 to 35 mph gusts. Cold air advection will be
underway, with 850 mb temperatures generally from around -4C to
-6C over Delmarva and southern New Jersey to as low as -8C over
the southern Poconos and northwest New Jersey. This will yield
below normal highs in the low to mid 50s, except a few degrees
cooler in the higher elevations of the southern Poconos and a
few degrees warmer in southern Delmarva.

Winds diminish Wednesday night as the pressure gradient
relaxes. Clear and, relatively speaking for mid-April, cold with
lows in the low to mid 30s.

Turning warmer on Thursday with high pressure sliding offshore
and warm air advection developing. Highs will be in the upper
50s to around 60. Lows Thursday night will be in the mid 30s to
around 40.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Warming into the weekend with high pressure offshore and return
flow setting up. With a warm front lifting north through the
region, some showers may develop over the far northern areas
late Friday and Friday night. Highs on Friday will be in the mid
to upper 60s to around 70.

Low pressure passing north of the area on Saturday will drag a
cold front through the region late Saturday and Saturday night.
Ahead of the front, highs should be able to warm well into the
70s and around 80. Some showers will be possible with the
passage of that front.

High pressure returns for Sunday and Monday with slightly
cooler, yet still above normal temperatures with highs in the
60s to around 70.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of tonight...Prevailing VFR conditions. ACY could see
moments of MVFR conditions with a batch of lingering showers
moving overhead around daybreak. Southwest winds around 5 knots.

Tuesday...Mainly VFR ceilings. Some showers around especially
in the afternoon which could result in mostly MVFR visibilities
for a time. A locally brief thunderstorm cannot be ruled out.
Westerly winds increasing to near 20 knots with gusts up to 35
knots. Moderate confidence.

Tuesday night...VFR and still windy. W to WNW gusts up to 25-30
kts. High confidence.

Outlook...

Wednesday through Wednesday night...VFR. W-NW winds 15 to 20 kt
with 30 to 35 kt gusts during the day Wednesday, diminishing
Wednesday night.

Thursday through Thursday night...VFR.

Friday...VFR.

Friday night through Saturday...Generally VFR, but sub-VFR
possible in SHRA.

&&

.MARINE...
A Small Craft Advisory is in effect for Tuesday beginning at 10
AM on Delaware Bay and 1 PM on the ocean zones. West winds near
20 knots with gusts up to 30 knots. A few gusts along the coast
to near 35 knots are possible. A few isolated showers may cause
locally stronger wind gusts in the afternoon.

Outlook...

Wednesday through Wednesday night...SCA conditions expected
Wednesday for W-NW winds 15 to 20 kt with gusts up to 30 kt and
seas up to 5 feet. Conditions subside to sub-SCA levels
Wednesday night.

Thursday through Friday...Sub-SCA conditions.

Friday night through Saturday...SCA conditions possible for S
winds 15 to 20 kt with gusts up to 25 kt.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 10 AM this morning to 6 PM EDT
     Wednesday for ANZ430-431.
     Small Craft Advisory from 1 PM this afternoon to 6 PM EDT
     Wednesday for ANZ450>455.

&&

$$

SYNOPSIS...MPS
NEAR TERM...MJL
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...MJL/MPS
MARINE...MJL/MPS