Area Forecast Discussion
Issued by NWS State College, PA-- Highlight Changed Discussion --
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FXUS61 KCTP 160302
Area Forecast Discussion
National Weather Service State College PA
1002 PM EST Wed Feb 15 2017
A brief cold air surge via northwest flow will promote snow
showers over the Alleghenies with light to moderate snow
accumulation in the Lake Erie snowbelt and higher elevations.
After the coldest day of the week on Thursday, temperatures
will moderate on Friday followed by a stretch of spring-like
weather over the weekend and into early next week.
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
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Newest NAM supports the going forecast very strongly. Will
freshen up the WSW.
Best moisture seems to be flowing into the Laurels, but visbys
have never been all that terrible this evening. However, the
long-duration and dryness/fluffiness of the snow support the
forecast snow amounts.
Steepest lapse rates crossing central PA early to mid afternoon
with widespread snow showers and embedded isolated squalls.
Surface temperatures at or above freezing across central and
eastern areas...and falling into the upper 20s across the west
and north as of 230 PM. Sufficient instability for the
remainder of the afternoon to produce sct to nmrs SW and highly
localized SW+ central and northeastern counties...with
downsloping and warming leading to just flurries of little
consequence it appears over the Lower Susq River Valley and
temperatures in the lower 40s.
NW flow regime with lake effect and upslope snow bands
ramping up through tonight. Winter Weather Advisory for
Somerset County in effect for favorable orographics, especially
into western half of the county, for 3 to 5 inches. Lake Effect
snow advisory remains in effect for Warren County where high
res models cont to show accums focused across the far NW part of
the county in the perennial Lake Erie snowbelt. The heaviest
snow is expected overnight into Thursday morning with some
longer fetch bands reaching back to the Upper Great Lakes/Huron
NW winds will be gusty into this evening, with some 40+ mph
gusts accompanying some of the squalls. Blustery and cold
conditions prevail tonight with lows in the mid teens-20s and
minimum wind chills in the single digits to around 15F.
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.SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
Widespread LES/upslope snow showers continue over the
Alleghenies and Laurel Highlands early Thursday before
decreasing in coverage and intensity through the afternoon. Sfc
high pressure ridge will build into western PA by late afternoon
and put any lingering -shsn to bed by Thursday night...leading
to dry conditions later Thursday night.
Nicely channeled northwest flow will again produce gusty winds
throughout the day. Thursday will be the coldest day of the
week with max temps ranging from the lower 20s north to the mid
to upper 30s southeast...with apparent temps ranging from 10-25F
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
There seems to be a model consensus for the location of an upper
level low that should be situated over Nova Scotia. This system
should continue to pull northward. This will allow for a building
high that, from the latest mid range models, should be dominating
the upper mid west and southern central Canada. This high should
weaken as its eastward prorogation is dampened by the quasi
stationary low in the east. This will mean locally that the near
normal temperatures Thursday night into Friday morning will trend
warmer Friday and into next week. A fairly dry period with the
next chance for significant precipitation next week and the
ensembles of the long term models have divergent solutions. The
big story is the warm air advection next weened into next week.
Max temperatures are progged to be 10 to 15 degrees above normal
Saturday into mid next week.
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
A deep storm developing off the east coast will keep gusty
winds across the region tonight into Thursday.
Snow showers will be across the mountains, with restrictions,
mainly at JST and BFD. MVFR cigs will be possible at AOO and
UNV at times tonight.
The snow showers will slowly taper off later on Thursday,
as the flow becomes less cyclonic and warming aloft occurs.
Temperatures will moderate by the end of the week into next
week, as high pressure moves off the east coast.
VFR conditions will return to the area by Friday.
Fri and Sat...No sig wx expected.
Sun and Mon...Mainly VFR conditions.
Lake Effect Snow Advisory until 4 PM EST Thursday for PAZ004.
Winter Weather Advisory until 10 AM EST Thursday for PAZ033.