Bensalem, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

991
FXUS61 KPHI 052218
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
618 PM EDT Mon May 5 2025

.SYNOPSIS...
An upper level low will slowly move northeastward and cross the
Northeast and Mid-Atlantic regions by Tuesday night, then it will
lift out during Wednesday. A cold front will cross our area
Wednesday night and Thursday morning. Another upper level low
develops across the Northeast and Mid-Atlantic regions Thursday
night and Friday with weak low pressure nearby, then it shifts
northeast on Saturday. A cold front may then move through during
Sunday with high pressure arriving for Monday.

&&

.NEAR TERM /THROUGH TUESDAY/...
Severe Thunderstorm Watch 228 is now in effect for the eastern
shores of Maryland until midnight.

Low pressure lies over southeast Ohio, and a warm front extends
out from that low across northern Delmarva and southern New
Jersey. Meanwhile, a secondary low lies on the cold front
extending out from the primary low and is over the Southeast.
The secondary low will lift north towards the Mid-Atlantic and
Delmarva and will merge with the primary low over the eastern
Great Lakes and Ohio Valley late tonight. Showers and
thunderstorms developing over the Mid-Atlantic will lift north
towards the Delmarva Peninsula. Currently about 1000 to 1500
J/kg of SB CAPE lies over Delmarva and although 0-6 km Bulk Wind
Shear is minimal, generally around 20 kt, this may be enough to
generate some strong to severe thunderstorms, some of which may
clip the eastern shores of Maryland.

Cloudy, showery, and foggy conditions will impact the rest of
the region late tonight.

For tonight, remaining cloudy and showery overall with some
areas of fog. Greatest threat for dense fog will be near coastal
areas and in the higher terrain in eastern PA and northern NJ.
The best chance for showers will be after midnight as more
unstable air moves in aloft overnight. This will also result in
some better chances for thunder across the region compared to
the daytime today. Low temperatures mainly in the mid 50s to low
60s.

For Tuesday, winds start to turn southerly as the surface low
relocates almost due north of our region towards evening. This
should allow for drier (less marine influence) air to move in,
and thus a bit more sun to peak through as the day wears on,
especially south and west of Philly. This will help bring temps
up well into the 70s to near 80 degrees in some spots, and
increase diurnal instability. Thus, after a bit of a lull in the
morning, expect scattered showers and a some t-storms to
redevelop Tuesday afternoon, especially near and northwest of
I-95, where a marginal risk of severe weather has been outlined
by SPC. Cannot rule out a severe storm or two, but generally
sub-severe storms are anticipated, with gusty winds, small hail,
and locally heavy rainfall being the main threats.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
The pesky closed low finally exists stage right during
Wednesday, however another upper-level trough that looks to
close off starts to arrive during Thursday.

As the closed low starts to weaken and eventually open up
through Wednesday, it slides across our area Tuesday night and
then shifts to our northeast during Wednesday. Some additional
showers and even a few thunderstorms look to continue Tuesday
night, then some lingering showers possible Wednesday before the
weakening system clears our area. A few gusty thunderstorms
with even some hail may occur Tuesday evening before weakening
mostly across eastern Pennsylvania to northern New Jersey.

As we go through Thursday, quickly on the heels of the
departing and weakening closed low, another upper-level trough
starts to arrive during Thursday. This feature is also forecast
to close off as it arrives more into the Mid-Atlantic region and
Northeast Thursday night. Increasing flow aloft on the east
side of the trough will assist with warm air advection and
pressure falls will lead to surface low development near our
area. Increasing forcing for ascent should start to overspread
our area as Thursday progresses and therefore some showers are
forecast to develop. These may become more widespread late in
the day and at night, although the coverage is less certain
especially whether or not a more organized area of rain starts
to organize. Increased the PoPs some more from previous
forecast. High temperatures are forecast to top out into the low
to mid 70s across much of the area, although cooler right along
the coast and across the higher elevations.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Summary...Cooler to end the week, then temperatures moderate over
the weekend into early next week.

Synoptic Overview...A closed low shifts across the Northeast and Mid-
Atlantic Friday, then it looks to weaken and lift out during
Saturday. Some upper-level troughing then remains across the
Northeast and adjacent Canada Sunday, however some mid level ridging
may then start to arrive from the west into Monday. At the surface,
weak low pressure is forecast to be near or just off the New Jersey
coast Friday before shifting northeastward through Saturday. A weak
area of high pressure may arrive during Saturday, however a cold
front looks to arrive on Sunday.

For Friday...A closed low settles across the Mid-Atlantic and
Northeast. This will also support weak low pressure along or just
off the New Jersey coast. The combination of height falls, surface
low pressure development, colder air aloft and stronger forcing for
ascent will result in at least some showers. Some guidance
suggesting a period of rain could be possible, especially the
guidance that is slower with the northeastward motion of the trough
and associated surface low. While the air aloft gets colder as the
core of the closed low arrives, plenty of clouds may limit the
overall instability. Given the forecast strength of this system,
cannot rule out some low-topped thunderstorms. That risk looks to be
low at this time. The surface low lifts north and northeastward
through the night and this will result in the showers tapering off
from the west and south. If showers end up to be less in coverage
and there is no period of rain, then temperatures could be warmer
pending more breaks of sunshine.

For Saturday and Sunday...The closed low is forecast to weaken as it
lifts out of the region during Saturday, however some lingering
troughing aloft may remain across our area. Drier conditions are
forecast and with heights rising some in the wake of the closed low,
temperatures will start to moderate. An upper-level trough then
sliding across much of eastern Canada will arrive across the
Northeast Sunday and this will toss a cold front across our area
during Sunday. As of now, the moisture looks to be limited and the
forcing is weak therefore any shower chances look to be on the low
side with the front.

For Monday...Some mid level ridging should arrive from the west and
this will allow surface high pressure to build over our region. This
will result in warmer temperatures, although with lighter flow there
could be a sea breeze in the afternoon. The surface high may start
to shift offshore Monday night with return flow already starting,
and some guidance has a disturbance off the Southeast U.S. coast.
Will have to see if this system occurs and if any moisture from it
starts to advect northward into parts of our area at night.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...MVFR/IFR CIGs lie from around KPNE northward, and
south of KPNE, including KPHL, KILG, KMIV, KACY, CIGs are VFR as
some dryer air is spreading in from the southeast. CIGs will
lower to IFR/LIFR throughout after 00Z, and then MVFR or lower
VSBYs will develop in BR and SHRA late tonight. E-SE winds 5 to
10 kt. Low confidence on timing change from VFR to IFR, but
high confidence in IFR and lower conditions overall.

Tuesday...Initially IFR will lift to MVFR then VFR between
about 15-18Z. Greatest chance for showers and thunderstorms will
be mainly 18Z and later. Moderate confidence overall.

Outlook...

Tuesday night and Wednesday...Times of sub-VFR conditions with some
showers and a few thunderstorms.

Thursday and Friday...Some areas of sub-VFR conditions may develop
with some additional showers.

Saturday...VFR.

&&

.MARINE...
Easterly winds around 10 kts prevail today, but the persistent
onshore flow as low pressure moves through the region appears
likely to cause seas to gradually build, with waves reaching 5-6
feet tonight into Tuesday. Some areas of dense fog have
developed near and north of LBI in NJ, which has prompted a
Dense Fog Advisory with visibility 1 NM or less. The Dense Fog
Advisory was expanded south to include the rest of our coastal
waters for tonight, with areas of dense fog expected to develop
as a warm front lifts north.

Small Craft Advisory goes into effect on the ocean waters
tonight and Tuesday. Winds turn southerly later on Tuesday with
some gusts up to 25 kts at times as well, but the main cause of
the headline will be the wave heights. For this reason, no Small
Craft Advisory is planned for the bay.

Aside from the winds and seas, spotty thunderstorms will be a
concern, especially on Tuesday afternoon.

Outlook...

Tuesday night...Seas may linger around 5 feet for a time on the
ocean zones.

Wednesday and Thursday...The conditions are anticipated to be below
Small Craft Advisory criteria.

Friday and Saturday...Small Craft Advisory conditions possible,
mostly on the ocean zones, due mainly to seas increasing for a time
to around 5 feet.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Dense Fog Advisory until 6 AM EDT Tuesday for ANZ430-431-
     452>455.
     Dense Fog Advisory until 11 AM EDT Tuesday for ANZ450-451.
     Small Craft Advisory until 6 PM EDT Tuesday for ANZ450>455.

&&

$$

SYNOPSIS...Gorse
NEAR TERM...MPS/RCM/Staarmann
SHORT TERM...Gorse
LONG TERM...Gorse
AVIATION...Gorse/RCM/Staarmann
MARINE...Gorse/RCM/Staarmann