Warminster, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

374
FXUS61 KPHI 100153
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
953 PM EDT Wed Apr 9 2025

.SYNOPSIS...
Cool and dry high pressure will shift offshore overnight. Low
pressure then arrives late Thursday through Saturday, resulting
in moderating temperatures and another prolonged period of wet
and unsettled weather. The low pressure system may linger near
the area into Sunday. High pressure will push offshore to our
south into early next week, resulting in a period of above
normal temperatures.

&&

.NEAR TERM /THROUGH THURSDAY/...
This evening, high pressure moves off the coast as low pressure
advances eastward and reaches as far as Ohio by around sunrise
Thursday. Skies remain mainly clear before clouding over
through the overnight. Expect lows generally in the middle to
upper 30s south and the low to mid 30s north. Our Delmarva
Counties that have officially entered the growing season will be
close to Frost Advisory criteria but given the temperatures
will be pretty marginal and RHs should stay below 80 percent,
opted to hold off on issuing Frost Advisory.

For Thursday, the aformentioned low will weaken as it moves
eastward through Ohio as energy in the upper levels will be
diving more to the south. Despite this, there will be enough
warm advection and PVA driven lift to bring a bit of rain at
least into portions of eastern PA by midday into the afternoon.
Our POPs from Berks County northward toward the Poconos reach to
around 60 percent. Meanwhile POPs near the I-95 corridor will
max out around 20 to 30 percent. Also worth noting, there could
be a little wet snow mixing in at times over the Pocono Plateau.
Highs For Thursday should be pretty similar to today despite
the WAA pattern due to it being mainly cloudy.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
The period Thursday night through Saturday will be unsettled,
generally wet, and cool.

Broad low pressure moves into western New York/southern Ontario
on Thursday Night before occluding on Friday. This will result
in some light rain developing Thursday Night over the area, but
rainfall amounts will remain light around 0.10" to 0.25" or so.
There should be a brief break sometime on Friday, most likely
around early to midday, but a new surface low looks to develop
over the Carolinas, lifting northward up the coast through the
day on Friday. This will bring another round of heavier and more
widespread rain into Friday Night as we continue to make
inroads on the ongoing drought.

NBM Probability of 1+ inch of rain Thursday through early
Saturday is around 70-80% across the region, though some
embedded heavier rain looks likely to the point some spots may
get as high or even over 2 inches of rain. Probability of 2+
inches of rain through Saturday hovers around 20-30%, a not
insignificant number especially since the highest probabilities
are centered near the I-95 corridor. This could result in some
urban and poor drainage flooding of low lying areas. A Marginal
Risk (1/4) remains in place for most of the region for excessive
rainfall for Friday through Friday night. Cannot rule out some
rumbles of thunder either, mainly from the I-95 corridor and
east, though no severe weather is anticipated.

The surface low that moves up the coast on Friday night will
meander nearby as an upper level trough over the eastern US
tries to close off. This should result in some scattered to
numerous showers hanging around through Saturday. Additional
rainfall amounts around 0.10" to 0.25" at most.

Temperatures through the end of the week and first half of the
weekend will be in the mid 40s/low to mid 50s for highs and mid
30s/low to mid 40s for lows.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A deep upper level trough crosses the region on Saturday Night,
with an associated surface low slowly pulling away. Drier air
begins to work in on the backside of the low with showers
gradually moving out. Pretty good agreement among guidance in
the positioning and timing of the upper level trough passing.
With the surface low pulling away, Sunday should be mainly dry,
though a few showers are possible near the coast. Temperatures
will be a few degrees below normal with lower heights aloft and
northwest flow ushering in some cooler air, bringing highs in
the 50s to near 60 degrees.

Upper level ridging begins to work in on Sunday Night, with
high pressure at the surface sliding by to the south into next
week. With heights rising and flow turning more southwesterly,
temperatures quickly moderate for Monday and Tuesday, even going
into above normal territory. Pretty good consensus that highs
likely get to near 70 degrees on Monday, and especially Tuesday
when some mid 70s are possible at lower elevations. A frontal
system could come in sometime on Tuesday, knocking down
temperatures toward more seasonable levels for the middle of
next week. This frontal system could also bring some
precipitation, though low confidence on that as the upper air
pattern solutions diverge beyond Tuesday.

Overnight lows through the long-term look to be in the 40s,
with perhaps some areas up north getting into the upper 30s. The
Frost/Freeze program for spring expands tomorrow to areas south
of I-78, and temperatures overnight in the long term should be
warm enough to not have any cold weather concerns for
agriculture.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Increasing clouds overnight but remaining VFR. S/SE
winds around 5 knots. High confidence.

Thursday...Primarily VFR, though MVFR conditions possible,
mainly for KRDG/KABE with scattered showers and lower ceilings
around. S/SE winds increasing to around 10 knots with some gusts
of 15 to 20 knots possible by afternoon. Moderate confidence.

Outlook...

Thursday Night...A mix of MVFR/IFR likely with showers moving
through.

Friday through Friday Night...IFR conditions expected with
rain, which could be heavy at times, moving through.

Saturday...Sub-VFR conditions possible with some scattered
showers and low clouds around.

Saturday Night...Sub-VFR conditions possible with chance of
rain (30- 40%) and low clouds around.

Sunday and Monday...VFR. No significant weather.

&&

.MARINE...
There could be a few wind gusts to around 20 knots Thursday
afternoon but conditions are expected to stay below Small Craft
Advisory levels. Seas generally around 2 to 3 feet with the
benign weather.

Outlook...

Thursday Night...No marine hazards expected.

Friday through Sunday...SCA conditions expected as seas build
toward 5 to 7 feet. Wind gusts 25-30 kt possible late Friday
into Friday Night.

Sunday night through Monday...No marine hazards expected.

&&

.FIRE WEATHER...
Humidity levels will be higher for Thursday with minimum RH
values generally around 40 to 60 percent precluding any fire
weather concerns.

&&

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

&&

$$

SYNOPSIS...Hoeflich/Staarmann
NEAR TERM...Fitzsimmons/MJL
SHORT TERM...Hoeflich/Staarmann
LONG TERM...Hoeflich/Staarmann
AVIATION...Fitzsimmons/Hoeflich/MJL
MARINE...Fitzsimmons/Hoeflich
FIRE WEATHER...