Baumstown, Pennsylvania Weather Forecast Discussion

828
FXUS61 KPHI 191017
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
617 AM EDT Fri Sep 19 2025
.SYNOPSIS...
A weak area of high pressure will remain across the Middle
Atlantic region for much of today with a cold front pushing
through the region tonight. A strong high pressure system will
build southeast over the weekend before weakening and shifting
slowly eastward through the first half of next week, with
moderating temperatures and a few chances for rain.
&&
.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis places weak high pressure over our
region, centered on the central Appalachians. A cold front is
pushing southward across the St. Lawrence River Valley along
the US/Canadian border, with a stronger high pressure following
behind it in southern Canada. Aloft, a broad trough is
positioned across much of eastern Canada into the northeastern
United States, with a weak ridge to our west across the western
Great Lakes and Ohio Valley.
Through tonight, the ridge aloft will actually build eastward
toward our region even as the surface cold front presses
southward into our area. Thus, there is very little risk for any
precipitation or even a whole lot of clouds with this surface
front which is pretty lacking for any upper-level support.
Therefore, with northwesterly winds prevailing, expect a mostly
sunny and warm day, though humidity will diminish a bit. Highs
generally in the 80s after any patchy early morning fog
dissipates (though that looks very patchy at this time).
Tonight, northerly winds continue as the surface front settles
south and the high to the north builds in somewhat, while the
ridge aloft also builds in. Thus, a dry night is on tap. Lows
40s in the Poconos and NW NJ, 50s I-95 corridor away from the
urban core, and 60s Delmarva, urban core and immediate NJ
shore.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A high pressure system will be our main surface feature for the
short term period. The high will be in control across the
northeast on Saturday with dry conditions and a mostly to partly
sunny sky. Due to the onshore flow from the high pressure
system being to our north, there is the potential for more cloud
cover near the coastal areas with even a light shower possible.
Overall, not expecting much in the form of precip Saturday as
the high pressure system also has a pretty dry airmass with it.
Highs on Saturday will be in the 70s. On Saturday night, lows
are in the low 50s to low 60s with clouds increasing. We stay
dry overnight.
It is a similar setup on Sunday with the high pressure system
starting to sink southeast a bit. We continue to have onshore
flow which may lead to the potential for a slight chance of
showers for parts of Delmarva and coastal areas. Otherwise, it
is a mostly to partly sunny day with highs mainly in the 70s.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
Our surface high pressure system remains in control on Monday
but it is starting to shift more to the east. Due to the
placement of the high as it moves east, we start to get more of
southerly wind direction which will allow moisture to increase.
We are mostly to partly sunny on Monday with high temperatures
in the 70s.
A warm front approaches from the west Monday night into
Tuesday. Clouds increase west to east on Monday night and
continue to build into Tuesday. As this warm front moves
through, we start to see the potential for showers increase from
west to east. The best potential for any showers or even an
isolated thunderstorm is during the day Tuesday. Most of the
shower coverage on Tuesday will be isolated to widely scattered
with PoPs 30-50% currently. High temperatures on Tuesday will be
in the mid 70s to mid 80s.
On Wednesday, a cold front will be sinking southeast early in
the day with the potential for some isolated to widely scattered
showers lingering through the day Wednesday as that cold front
passes through. Some model guidance wants to develop a low along
this front which would enhance precip coverage and
organization. There is uncertainty regarding this scenario and
how developed the low would become. For now, PoPs Tuesday night
and Wednesday are capped at 20-30% with the cold front passing
through. Highs on Wednesday are mainly in the 70s.
Some showers may stick around for Thursday but a high pressure
system will also be building in from the north. Latest model
guidance trends have shown the high pressure system being
stronger which keeps the area on the drier side. Right now, PoPs
are capped at slight chance given the uncertainty at this point
in the forecast period. We stay partly to mostly cloudy on
Thursday with highs in the low to mid 70s.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Today...VFR expected after any early fog. Some fair weather
afternoon cu with SCT 035-045 bases possible. Northwest winds 10
knots or less in the afternoon. High confid.
Tonight...VFR with northwest winds shifting northeast overnight,
but remaining 10 kts or less. High confidence.
Outlook...
Saturday...VFR. No significant weather.
Saturday night through Sunday night...Restrictions are possible
depending on the extent of potential marine stratus.
Monday through Monday night...VFR. No significant weather.
Tuesday through Wednesday...Period of Sub-VFR conditions are
possible in isolated showers and storms, particularly during the
afternoon hours.
&&
.MARINE...
Fair weather will continue on the waters today. A cold front
will approach later today and while no significant weather is
expected with it, winds will switch to south as it approaches.
Seas will be around 2 ft today. 1 to 2 ft waves for Delaware
Bay. Winds shift northerly behind the front tonight, and may
gust near 25 kts late with seas building to 3-4 ft, but
confidence on SCA headlines is low at this time.
Outlook...
Saturday through Monday...Northeast to east winds could
approach or exceed 25 kts Saturday into Sunday. Seas also will
likely become elevated, at times near or exceeding 5 feet,
Sunday through Monday. Therefore, an SCA will likely be needed
for at least part of this period.
Monday night through Wednesday...Conditions are expected to be
below SCA criteria with winds under 25 kt and seas under 5 feet.
Rip Currents...
For today, a more southerly wind near 10 mph is forecast to
develop with an east-southeast swell around 8 seconds. Breaking
waves in the surf zone are forecast to be a little lower (around
2 feet) than Thursday, and therefore continued with a LOW risk
for the development of dangerous rip currents at all beaches.
For Saturday, a surge in northeasterly winds are forecast to
develop from north to south, with speeds increasing to 15-20
mph. A southeast swell is forecast to be on the weaker side with
wave heights 1-2 feet with a period of 5-7 seconds. Building
waves in the surf zone (2-4 feet) should be much more dominant
over the swell. As a result, went with a MODERATE risk for the
development of dangerous rip currents at the Jersey Shore and
LOW at the Delaware Beaches. If the stronger wind surge and
higher breaking waves arrive faster at the Delaware Beaches, the
rip risk will then increase.
For specific beach forecasts, visit weather.gov/beach/phi
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
SYNOPSIS...Cooper/Guzzo/RCM
NEAR TERM...RCM
SHORT TERM...Guzzo
LONG TERM...Guzzo
AVIATION...Guzzo/RCM
MARINE...Gorse/Guzzo/RCM

NWS PHI Office Area Forecast Discussion