Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
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FXUS61 KCTP 280019
Area Forecast Discussion
National Weather Service State College PA
719 PM EST Mon Feb 27 2017
Return flow around high pressure off the mid-Atlantic coast
will bring milder air into the region through the middle of the
week. Low pressure will move across the Ohio Valley and track
north of Pennsylvania midweek, bringing a rainy period followed
by a potent cold front late Wednesday. Much colder air is in
store for late week, with sub-normal temperatures likely over
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Weak shortwave sliding into the area from the west bringing just
enough oomph to kick off very light rain across the southwest
this afternoon - though it took a while to moisten the lower-
levels from earlier dewpoints in the mid teens to their current
values in the lower 30s. The light rain area will drift
northward through this evening, though by then it will be
weakening as wave slips by. Kept mention of very low pops for
northern mtns with best bet being sct sprinkles overnight. Temps
tonight should remain about 10F above normals.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Low pressure deepening over the upper midwest Tuesday will push
a warm front into the state bringing showers and perhaps a
thunderstorm or two late day or Tue night. Overall, precip will
be on the light side during this period. Temps on Tuesday will
be another 10F higher than today thanks to the warm advection
and morning sunshine - especially in the south. Readings climb
back into the 50s north/60s south. A very mild night in store
for Tue night as warmer air surges in from the SW ahead of a
potent low pressure system - keeping lows in the 50s most
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Severe thunderstorm risk is the primary focus on Wednesday with
another strong cold front impinging on a convective environment
characterized by unseasonably warm temperatures, above normal
PW, relatively low instability and very strong low-to-mid
tropospheric winds. There is still some uncertainty in the
details such as timing and whether CAPE can be realized due to
preceding clouds/pcpn. Despite depicting clear potential for
strong to severe storms given high shear/low cape scenario,
there is still room for adjustments as models begin to converge
on a consensus solution. The key message is preparation for what
could evolve into another damaging thunderstorm wind event. The
threat and risk information have been communicated through the
HWO and social media/decision support channels with updates
coming tomorrow morning with the Day 2 SPC outlook.
It will turn noticeably colder Wednesday night into Thursday as
strong NWLY post-frontal flow directs colder air into the area.
Widespread 30-35 mph wind gusts are probable with 40+mph gusts
possible on the Laurel ridges. The surge of CAA will bring snow
showers downwind of Lake Erie into the NW Alleghenies/Laurels
with minor accumulations (<1 inch) forecast Wed. night into
A broad trough remaining over the Northeast U.S. on Friday will
push off the coast by the beginning of the weekend. A clipper
system associated with the final piece of shortwave energy
embedded in the trough may bring a mix of snow and rain Thursday
night into Friday with a light accumulation possible. The mean
500mb flow is fcst to flatten out a bit over the weekend with
temperatures moderating nicely to above average after bottoming
out on Friday. Overall, the pattern looks fairly quiet over the
weekend and into early next week with another strong frontal
system possible by March 7-8.
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Weak shortwave sliding through the area has triggered a few
showers and areas of drizzle, mainly across the central
mountains region. This has been accompanied by areas of MVFR
As shortwave moves east...expect mainly VFR conditions overnight
As a warm front approaches, expect lowering conditions, with
showers moving into the west during the later afternoon Tuesday.
Some restrictions in ceilings and visibilities are expected
late (after 20z) in the western airfields.
Tue...Rain showers/Sub-VFR conditions developing from W to E
Wed...Rain showers/Sub-VFR reductions. Breezy. LLWS likely.
Chance of thunderstorms.
Wed Night...Strong FROPA early with gusty winds/tstms.
Thu-Fri...Sub-VFR likely west in sct snow showers. NW winds. VFR
Sat...No sig wx.