Beartown, Pennsylvania Weather Forecast Discussion

209
FXUS61 KCTP 161121
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
721 AM EDT Tue Sep 16 2025
.SYNOPSIS...
* Cloud cover will gradually increase and lower from east to
  west across the Southern Poconos, Susquehanna Valley and
  eventually the Southern and Central Mountains later tonight
  and Wednesday, while a potential for valley fog will be found
  across the northern tier early today.
* Periods of rain, mainly light, will develop across
  southeastern Pennsylvania Today through Wednesday.
* Dry conditions return areawide on Thursday and will continue
  through the first half of the weekend.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Well defined sfc low pressure with some deep convection
occupying its NW quadrant, was located just east of Cape
Hatteras, NC and drifting slowly north-northwest.
A deepening and slightly veering ENE to Easterly LLVL flow will
develop across the Lower Susq Valley and Adj SE PA throughout
today. A few sprinkles could reach the ground across our far SE
counties this afternoon, followed by the NW edge of a shield of
light to MDT rain entering the Lower Susq Valley early tonight.
To the NW of this advancing, layered cloud shield will be mainly
clear skies and light wind, leading to valley fog across
northern PA through 13Z today.
On the balance today, sunshine will be mixed initially with
mainly thin, high clouds across the Central and Northern Mtns
today before some thickening mid clouds spiral in from the
east/southeast late this afternoon/evening.
High temps today will be mainly in the upper 70s...to low 80s
across the Mid Susq Valley. Maxes could be capped off between
73-75F across portions of York and Lancaster counties where
cloud cover thickens up first under the developing cold air
damming setup.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
4 AM Update...
Main change was to bring in a more definitive forecast of
overcast conditions acrs the SE third to half of the CWA for
tonight and Wednesday with an increased chance of some periods
of steady light to briefly moderate rain, near and to the SE of
the I-81 corridor.
As a result of the thicker, overcast layer of stratus (topped
by one or more layers of mid to high clouds) temps were trimmed
a bit across the SE third to half of the CWA for Wednesday.
Readings may climb no higher than the mid to upper 60s
Wednesday, along and to the SE of Interstate 81.
NBM has a difficult time achieving 100 percent cloud cover with
this fairly obvious, cold air damming setup under deepening
easterly flow. a thick overcast layer of stratus is likely
across the Lower and Mid Susq Valley by later tonight through
Wednesday with the Southern and Central Mtns likely seeing the
main surge of cloud cover after dusk this evening and seeing it
stick around through much of Wed.
Previous Disc...
Low pressure will lift slowly northward from the Outer Banks
and VA Tidewater off the Mid-Atlantic coast through the middle
of the week. Latest model guidance continues to indicate the
best chance for rain over the southeast zones (southeast of
I-81/78) where a moist/upslope easterly low-level flow will
bring better moisture returns. Further north/west, precipitation
is less likely; however, aforementioned easterly flow will
allow for more expansive cloud coverage and cooler temperatures
for much of the forecast area. Most recent QPF has tapered back
ever so slightly, keeping the southern reaches of Adams/York and
much of Lancaster County above 0.10" rainfall over a fairly
tight gradient. Precipitation Wednesday night is expected to
gradually move east of the area as the coastal low begins to
push further offshore.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A brief spell of dry conditions is once again expected in the
wake of the coastal low, with moderate-to-high confidence in dry
conditions beginning on Thursday and continuing through Saturday.
Recent model guidance has slightly slowed down with respect to
the low pressure system in the Midwest with a fair amount of
uncertainty between deterministic model guidance. Given these
changes, have decided to roll with NBM through Monday, with the
best chances of precipitation coming after sunrise on Sunday and
into the end of the long-term period.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
Any lingering valley fog will dissipate by 14Z, giving way to
VFR conditions under varying amounts of high clouds with
isolated showers possible in southeast PA. Winds will be out of
the east northeast at 5 to 10 knots with gusts of 15 to 20 knots
possible this afternoon at MDT and LNS. Clouds will gradually
thicken overnight, but with the exception of MDT and LNS, VFR
conditions will prevail. Those two sites will see ceilings drop
down to MVFR as showers move in from the south ahead of a low
pressure system.
Outlook...
Wed-Thu...Generally VFR, some SHRA possible (20-40%) SE PA.
Fri-Sat...VFR with AM valley fog.
&&
.CLIMATE...
Astronomical fall officially begins with the autumnal equinox
on Monday, September 22, 2025 @ 2:19 p.m. EDT. The Autumn 2025
season will last 89 days, 20 hours, and 43 minutes. Daylight
saving time will end just after Halloween with clocks falling
back at 2 a.m. Sunday, November 2, 2025.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/NPB
NEAR TERM...Lambert/Banghoff/NPB
SHORT TERM...Lambert/NPB
LONG TERM...NPB
AVIATION...Bauco
CLIMATE...Steinbugl

NWS CTP Office Area Forecast Discussion