Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
945 am EST Wednesday Jan 28 2015
High pressure will build over the region today...followed by an
Alberta clipper which will cross the area Thursday and Thursday
night. High pressure will return for late Friday into
Saturday. A new storm may bring a round of wintry weather for
later Sunday into Monday...before another surge of cold air works
into the area early next week.
Near term /until 6 PM this evening/...
Low clouds over southwestern areas will continue to dwindle and mix out
leaving all areas sunny by afternoon.
High pressure will build east from the Ohio Valley today...providing
abundant sunshine. Vertical mixing up to just 2 kft above ground level will lead
to a northwesterly breeze of 8-13kt...with gusts into the middle and
upper teens across the region near and to the east of the susq
Despite the sun...temperatures will remain well below seasonal
norms...in part due to fresh snow cover. Gefs mean 925temps
support highs only in the 20s. A relaxing pressure gradient will
result in a relatively light northwest wind by later in the day.
Short term /6 PM this evening through 6 am Thursday/...
high pressure and associated low precipitable water air mass will drift overhead this
evening. South-sserly surface flow and anomalously strong southwesterly flow
aloft develops early Thursday in advance of a fairly potent
clipper headed our way from the western glakes region.
High cloud shield will advance east across the region this
evening...before lowering and thickening to an Alto-nimbostratus
deck early Thursday across the west.
Any light snow prior to daybreak Thursday will be limited to the
extreme northwest...and even there it will be mainly in the form of non-
Low temperatures tonight will be in the single digits to lower teens.
Long term /Thursday through Tuesday/...
a strong...several to 8 hour shot of warm air advection aloft and moderately strong
upper level divergence associated with the right entrance region
of a 300 mb jet maximum across southern Ontario will lead to periods of
light /to briefly MDT snow/ focused across the northwest half of the
state Thursday afternoon into Thursday night.
Gusty west to northwest winds and bitterly cold air with wind
chills at or below advisory criteria appear likely for Friday into
early Saturday across the central and northwest part of the state with
steady or slowly falling temperatures during the day Friday.
Saturday still not looking too bad.
For Sunday...southern stream system with decent/relatively strong
dynamics and warm air advection should spread periods of snow across the state
Sunday afternoon and night with light to moderate accums possible.
For now went with snow. However...some mix could try to work into
the area...but think system is moving too fast to get much deep
warm air into the area.
System moves out quite quickly...and should be off the coast by
late Monday morning if not sooner.
Colder air will follow for Monday night into Tuesday. Did lower
temperatures Monday night.
Aviation /15z Wednesday through Sunday/...
High pressure will build in from the west today...bringing
widespread VFR conditions. Localized IFR/MVFR over southwestern areas
early will lift to VFR by middle day. Northwest winds will pick up a bit
the first half of the day...with breeziest conditions in the lower
susq where sustained nwrly winds 15 to 20 kts will develop after
sunrise and persist into middle afternoon.
Only thin high clouds poss tonight as winds become light.
Thursday...VFR to start...with restrictions spreading in from the
west starting midday.
Thursday night-early Friday...widespread IFR/MVFR in snow.
Sun...VFR to start...with late day restrictions spreading in from
near term...la corte/Lambert