Bethlehem, Maryland Weather Forecast Discussion

342
FXUS61 KPHI 041806
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
206 PM EDT Sat Oct 4 2025
.SYNOPSIS...
High pressure remains in control through Tuesday. A cold front comes
through on Wednesday. High pressure returns for the end of the week.
&&
.NEAR TERM /THROUGH SUNDAY/...
High pressure continues to dominate through the weekend.
Tonight, mostly clear skies with only some high clouds and light
winds. With high pressure positioned south of the region, dew points
will be in the low to mid 50s tonight, helping prevent much runaway
radiational cooling. Overnight lows will cool off into the low to
mid 50s as well. Some patchy fog may be possible early Sunday
morning as a result.
For Sunday, high pressure shifts slightly offshore, helping keep a
light, but warm S-SW flow across the region. Essentially a carbon
copy of Saturday, expect sunny skies and warm temperatures with an
afternoon high once again in the upper 70s to mid 80s.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Nice weather with above normal temperatures expected to kick off the
week. High pressure slides offshore with southerly return flow
setting up. This will result in high temperatures both Monday and
Tuesday getting into the upper 70s/low 80s. Overnight lows on Sunday
Night get down into the low to mid 50s, with mid to upper 50s on
Monday Night. With clear skies and light winds, some radiational fog
may develop on Sunday Night. The threat for fog is lower on Monday
Night as cloud cover may move overhead.
Some showers are possible later in the day Tuesday as a frontal
system approaches, but the bulk of the rain should hold off until
Tuesday Night and Wednesday (more on that below).
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
The above normal temperatures come to an end as we get into the
middle and end of the upcoming week. A fast moving shortwave digs
through southern Canada/northern US, moving toward the northeastern
US. At the surface, low pressure slides to the north with a cold
front slowly pushing into our region. This will bring a period of
rain late Tuesday into Wednesday. Guidance differs on the timing of
the front as of this writing and the trend with the latest 12z
global guidance was slower with the incoming front. Regardless,
still high confidence of a mid-week rain event and overall, it should
just be a beneficial rain. NBM probability of > 1 inch hovers
around 30-40% over the area. Some models have some elevated
instability, so cannot rule out a rumble of thunder, but the
severe and flash flooding threat seems very low currently.
Once the front clears on Wednesday Night, more seasonal temperatures
come for the end of the week. Another expansive area of high
pressure builds in, which should result in a dry and tranquil end to
the week. Temperatures on Thursday and Friday look to be in the 60s
with overnight lows in the 40s and some potential upper 30s in the
Poconos and northern NJ.
Beyond Friday, the forecast becomes a bit more uncertain. Some
guidance has high pressure holding firm through the weekend
while some want to bring a weak system through or to our south.
Still about a week out though, so stuck to the NBM.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...
Rest of today (through 00Z)...VFR with some passing cirrus. Winds
around 5 kts favoring a southwesterly direction. Sea/river/bay
breezes will shift wind directions more southerly by 18Z for
PHL/ILG/ACY. High confidence in prevailing conditions.
Tonight...VFR with winds light (2-5 knots) and generally favoring a
southwesterly direction. High confidence.
Sunday...VFR. South to southwesterly winds around 5 knots or less.
High confidence.
Outlook...
Sunday Night...Primarily VFR though patchy fog possible
(20-30%).
Monday through Tuesday...VFR. No significant weather.
Tuesday Night through Wednesday...Sub-VFR conditions expected with
periods of rain and low clouds coming through.
Wednesday Night through Thursday...VFR. No significant weather.
&&
.MARINE...
No marine hazards expected through Sunday. S to SW winds around 5-15
kts withs seas 2 to 4 feet.
Outlook...
Sunday Night through Monday Night...No marine headlines
expected.
Tuesday through Wednesday...Wind gusts on the ocean could get near
25 kt at times, resulting in potential SCA conditions.
Wednesday Night through Thursday...SCA conditions expected with
gales possible (20-30%). North/northwest wind gusts nearing 30 kt
with seas 5 to 7 feet.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
SYNOPSIS...Hoeflich
NEAR TERM...MJL
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Hoeflich/MJL
MARINE...Hoeflich/MJL

NWS PHI Office Area Forecast Discussion