Warminster, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

445
FXUS61 KPHI 142019
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
419 PM EDT Thu Aug 14 2025

.SYNOPSIS...
A cold front will push just south of the area tonight, where it
will stall out across the Mid Atlantic through the weekend.
High pressure will build across Quebec and New England into the
weekend. A stronger cold front will push through the region
Sunday night into Monday, with cooler and drier high pressure in
its wake through the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
A moisture laden airmass remains over the region and today
should be another day with weakly forced scattered convection. A
sea breeze has fired up and is pushing inland and will be the
trigger for at least some convection along the Atlantic coast.
Instability remains high, along with weaker shear aloft so I
dont anticipate much organization of the storms. The only
modulating factor today is that a boundary of drier air setup
over the Poconos and is generally sliding towards the southeast.
This is leading to the northern portions of the forecast area
less likely to see much in the way of thunderstorm development.

Given the high pwat values still remain over the region, any
showers that persist over a given location will have the
capacity to drop 1- 3" of rain in a hour. However due to the
more isolated coverage and the lack of signal over the urban
corridor, we`ve opted not to issue a Flood Watch for today.

The convection should again begin to wane this evening as we
lose diurnal heating with skies being more partly cloudy
overnight. Lows this evening should fall into the low 70s.
Patchy fog can`t be ruled out in areas that receive rainfall
today but confidence is lower on fog tonight then it was last
night.

In the absence of a strong frontal system clearing the region,
Friday will be another day with weakly forced convection over
the region. Isolated to Scattered showers with some embedded
thunderstorms will likely develop in the late morning to early
afternoon over portions of PA and then wane again heading into
the overnight hours. Severe storms are not expected.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
A cold front will remain nearby in the Mid-Atlantic region into
the weekend. Meanwhile, high pressure over eastern Canada
builds down into the Canadian Maritimes and Northeast. This will
keep an onshore flow over the area. High pressure over the
Northeast will begin to slide offshore, and winds will shift to
more of a westerly flow. Drier air, though still a bit humid,
filters into the region as dewpoints drop into the upper 60s to
around 70 on Saturday. Temperatures will once again be in the
80s. Some weak shortwave energy may support a few afternoon
showers and thunderstorms, but coverage will be isolated.

Lows Friday night in the mid 60s to near 70 degrees, and
turning cooler for Saturday night with lows mainly in the 60s
(still near 70 degrees in Philly and along the coasts).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Warm and humid on Sunday as return flow increases ahead of an
approaching cold front. That cold front crosses the region late
Sunday and Sunday night. Highs will be in the 80s to around 90,
and surface dew points will be up around 70, resulting in max
heat index values in the mid 90s or so. Though scattered showers
and thunderstorms will develop in the afternoon and evening,
there does not look to be much upper level support, as the base
of an upper trough remains well north of the area, and shortwave
energy does not look to be strong.

A stronger cold front will pass through the region on Monday,
which will usher in noticeably cooler and drier air. Once again,
some afternoon showers and thunderstorms will be possible, but
PoPs are fairly low at 20% for much of the area.

That front becomes nearly stationary over the Mid-Atlantic.
Several shortwaves approach from the west and may keep
conditions unsettled for the middle of next week despite high
pressure building in from the northeast. Highs will be in the
low 80s with dew points int he 60s. Will follow NBM PoPs and
carry 20% to 30% chances for showers and thunderstorms.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Generally VFR cigs across the terminals with isolated
to scattered showers and thunderstorms generally from TTN south.
Given the timing confidence, will generally carry PROB30`s for
thunderstorms from roughly 22z through 01z this evening. Cigs
and Vis will likely drop to sub-VFR in the presence of TSRA.
Moderate confidence.

Tonight...Showers diminish with the loss of daytime heating and
generally VFR cigs should prevail. Should one of the terminals
recieve much rainfall, some BR could develop overnight but
generally the feeling is that visibility should be unrestricted
overnight especially with drier air trying to make its way
south.

Outlook...

Friday night...Generally VFR. Scattered afternoon and evening
SHRA/TSRA.

Saturday...VFR.

Sunday through Tuesday...Generally VFR, but scattered afternoon
and evening SHRA/TSRA.

&&

.MARINE...
No marine headlines in effect though Friday. Winds generally
north to northeast 5-15 kts with seas less than 3 feet.
Scattered showers/tstms are expected to develop (again) today.
Locally strong winds and seas will be possible in and around any
thunderstorms.

Outlook...

Friday night through Sunday...Aside from an isolated
thunderstorm, no marine hazards are expected.

Monday through Tuesday...Winds and especially seas building to
advisory levels as swells begin arriving from what will soon be
Hurricane Erin. Advisory conditions likely persisting through
much of the week.

Rip currents...

For Friday, winds will be out of the northeast, turning east in
the afternoon, at 5 to 10 mph with breaking waves of 1 to 2
feet. The period will be around 8 seconds. As a result, there is
a LOW risk for the development of dangerous and life
threatening rip currents at the Jersey Shore and at Delaware
Beaches for Friday.

For Saturday, winds will be out of the northeast to east at
times at 10-15 mph with breaking waves of 2-3 feet. The period
will be around 4-5 seconds. As a result, there is a LOW risk
for the development of dangerous and life threatening rip
currents at the Jersey Shore and at Delaware Beaches for
Saturday.

For specific beach forecasts, visit weather.gov/beach/phi

&&

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

&&

$$

SYNOPSIS...Staarmann
NEAR TERM...Deal
SHORT TERM...MPS/Staarmann
LONG TERM...MPS/Staarmann
AVIATION...Deal/MPS
MARINE...Deal/Guzzo/Staarmann