Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 220325
Area Forecast Discussion
National Weather Service State College PA
1125 PM EDT Fri Oct 21 2016
A cold front moved southeast through Pennsylvania Friday. Blustery
northwest winds will usher in much colder air overnight and
Saturday. Occassional like showers are possible through Saturday
night especially across the mountain areas and the north. The
first bout of lake effect and upslope rain and snow showers are
possible over some of the higher ridge tops.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Made adjustments for the timing of the colder air which is
alreading sweeping into the lower Susq Valley and minor tweaks to
winds and dew points for the overnight period across the region.
Light showers or drizzle continues mainly over the western and
northern zones associated with the upper level trough with a few
spotty showers elsewhere. This is expected to coninute to diminish
overnight as the trough slowly pushes east.
Flooding abated and the smaller streams are receding with water
moving down the mainstem rivers now. No additional flooding
Something to consider for later tonight into early Saturday will
be the potential for the season`s first accumulating snows over
the RIDGETOPS of the Laurels and Northern Mountains. The guidance
has been persistent in bringing the coldest 850mb temps of the
season to date in behind our deep upper low. The potential for a
light slushy inch over the ridges is shown in the HRRR and NCAR
ensemble. The deterministic NAM and GFS are showing chances for
light accums over larger more general areas of the west and north,
this seems too generous given surface temps will be relatively
warm. Am thinking we will try to emphasize a light slushy accum
over the higher elevations only.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
A cool and unsettled day is in store Saturday as persistent
northwest flow and progressively cooler boundary layer air is
forced into the region. In fact 850 mb temps remain
below 0 throughout the day throughout central PA...and we`ll
certainly be looking at a few wet snowflakes mixing in at times
with some of the showers over the higher terrain of the northwest
and northern mountains. Under scenarios such as what we expect,
the best chance for measurable precipitation usually favors these
western and northern higher terrain areas with little more than
Maxes will range from the lower 40s northwest to the lower to
middle 50s southeast.
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As the surface and mid level systems track through eastern Quebec,
a broad cyclonic/northwest flow pattern will continue into early
next week. Models forecast lingering deformation or lake-enhanced
pcpn to come to an end by early Sunday morning. Gusty winds will
should weaken a bit with peak gusts not as strong as Saturday.
Focus will shift upstream to a series of shortwaves diving
southeast from the Upper Midwest/Great Lakes through the Northern
Mid Atlantic region. Models show some varying QPF solutions with
these features, but with limited moisture look for max amounts in
the 0.10 to 0.25 range over north-central PA. Following a brief
moderation in sfc- 850mb temps on Sunday, the aforementioned
shortwaves will bring a reinforcing shot of chilly air into the
area with below normal temps forecast into the middle of next
week. High pressure should provide dry weather Tue-Wed with pcpn
probs increasing toward the end of the week, with GFS/EC models
and ensembles showing a low pressure system reaching the Great
Lakes/Ohio Valley by Thursday.
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --For the 03Z package, adjusted the timing of the patchy
rain to the west some.
Across the southeast, left VCSH in, given more activity lifting
northward from MD.
Earlier discussion below.
00Z TAFS sent.
Problem will go from low clouds tonight to gusty winds
on Saturday. A few rain showers tonight, may mix with
some snow at JST and BFD by early morning.
Improving conditions for the later part of the weekend.
Visibility overall not expected to be very low over the next
few days, except for brief time periods in heavier rain and
Sun...No sig wx.
Mon...Mainly VFR. MVFR with rain showers possible NW.
Tue-Wed...No Sig Wx.
-- End Changed Discussion --
NEAR TERM...Watson/La Corte
SHORT TERM...La Corte