Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
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FXUS61 KCTP 161607
Area Forecast Discussion
National Weather Service State College PA
1107 AM EST Mon Jan 16 2017
High pressure will drift east and off the Mid Atlantic Coast
today. A warm frontal system will drift slowly northeast across
the region Tuesday, followed by a cold front pushing east through
the state Tuesday night and early Wednesday. High pressure will
follow and bring mainly dry conditions with temperatures several
degrees above normal from the middle of the week into the weekend.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Surface high over SERN Pa will provide the region with mainly fair
and dry weather through much of today. However warm advection is
already making itself felt with a shield of clouds that is
steadily progressing eastward from the complex frontal system
moving through the central part of the country.
There is a slight chance for some light rain across the SW part
of the Forecast Area late this afternoon, but most locations will
The cold start to the day and thickening cloudcover throughout
the day will hold temps lower by several degrees compared to
earlier guidance that suggested more sunshine. Highs will be
mainly in the mid 30s to mid 40s for the bulk of the forecast
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
The stubborn trough/upper low over the west coast will weaken and
lift across the southern plains into the Great Lakes region as a
pattern change begins.
A good portion of the upcoming week is shaping up to be mild and
showery (especially Tuesday) as the bulk of med range guidance
shows a ridge slowly retreating off the East Coast as remnants of
that west coast low get picked up by the northern stream and track
across PA during the midweek.
A warm front will be advancing northeast over the area early
tonight, spreading a shield of thick altostratus and nimbostratus
across central Pa. The strongest WAA is still indicated across
western PA toward the end of the day/this evening, where
scattered showers are possible.
Further south, an increasingly moist southeast flow at low
levels, will likely create some drizzle over the higher terrain of
A combination of the NAM and NBM were used to paint hourly and low
temps tonight. This greatly assisted in depicting the area where
light ice accretion is likely later tonight through the mid
morning hours Tuesday and the Areal Extent and duration of a
recently issued Freezing Rain Advisory.
Shield of mainly light rain overspreading the region from the SW
tonight will initially fall into very dry LLVL air. This will
allow temps to wet bulb down to the u20s and lower 30s over much
of central and northern PA changing the rain to mainly light
freezing rain between midnight and shortly after sunrise Tuesday.
For midday Tue into Tue night, deep southerly flow ahead of that
trough will bring a plume of anomalous PWATS over the region which
supports the idea of showery (periods of steady rain on Tuesday)
and mild weather. As has been the case frequently lately, the GFS
brings the trough through faster than the ECMWF. Followed close to
the Nat`l Blend of models vary high, 90-100 pops for Tuesday
surround on either side by mainly likely pops.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Winds turn westerly behind the system by Wednesday morning as
flow turns more zonal, but with no real cold air in sight, temps
will remain on the mild side and above freezing during the day.
Ridge re-establishes itself over the eastern U.S. for late in the
week, as mild SW flow persists over the midwest. Guidance
suggests energy will dive south along the west coast eventually
helping to strengthen the building upper ridge over the east.
We`ll be on the eastern side of this, so subtle shortwaves sliding
into the Midwest will bring varying amounts of cloudiness to the
west (less in the east) with low end chances for light showers.
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
Low cigs remain over the SRN portion of the flying area as a weak
SSE low level flow has kept the moisture locked in over the area.
The MVFR ceilings will slowly lift through early afternoon, but
overall trend will be for more cloudiness to increase from the
west as a frontal system takes aim at the area.
Restrictions are likely to develop/return during the evening with
widespread MVFR to LIFR conditions a good bet late tonight into
Tuesday. Rain will gradually spread across the airspace with risk
for freezing rain mainly over the northern 1/2 of the airspace
between 05-15Z Tue.
Wed...MVFR/IFR west; MVFR central to VFR southeast. Rain showers
west ending Wed ngt.
Thu-Fri...No sig wx.
Freezing Rain Advisory from midnight tonight to 10 AM EST
Tuesday for PAZ004>006-010>012-017>019-037-041-042-045-046-
NEAR TERM...La Corte/Lambert