Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
656 am EDT sun Mar 29 2015
A ridge of high pressure will slide southeast of the region early
today. A cold front will move out of the Ohio Valley Sunday night
and early Monday followed by another disturbance that will bring
the chance for more unsettled weather Tuesday. Upper level flow
will eventually become more zonal during the second half of the
upcoming week...leading to a slow moderation in temperatures.
Near term /through tonight/...
Skies are clear and winds are light almost everywhere as the high
slides off just to our southwest.
The day will start bright and cold but strong late March sun
should help US rebound into the upper 30s to middle 40s. Still well
below normal but some 10-15 degree warmer than Saturday when some
locations were close to their all time coldest maximum temperatures.
A cold front approaching from the Midwest will spread clouds and
the chance for some snow showers into western areas by midnight.
Short range guidance favors my western Highlands with the best
chance for precipitation...with probability of precipitation dropping off over central and
eastern areas due to downsloping flow. Ensemble quantitative precipitation forecast of .20" or
less looks reasonable with any light snow accums being mainly
confined to the west and north. Warm skin temperatures for the early part
of the overnight should limit amounts elsewhere.
Overnight lows look to bottom out a couple of degree either side of
Short term /Monday/...
The front will clear southeastern areas by early afternoon allowing for
the development of an all too familiar blustery and chilly
westerly flow with the usual Post frontal stratocu ceilings and
scattered rain/snow showers that usually favor western and norther
Highs from the middle 30s northwest will run some 10-15deg below normal.
Milder readings over the southeast will actually be not too far from
normal for late March.
Long term /Monday night through Saturday/...
The system on Monday will be followed in quick succession by
another shortwave for Tuesday. The operational GFS/ECMWF/NAM all
have very different solutions for the surface low with the NAM
being strongest and furthest north...and the European model (ecmwf) being weakest
and most south. I used a blend of model probability of precipitation and gefs/sref 850
temperatures to confine snow chances to areas north of I-80. I also
downplayed snow accums a bit given the expected high temperatures in the
middle to upper 30s. If the European model (ecmwf) solution pans out there will not be
much precipitation to speak of at all.
Naefsbc continues to show a break down in the extreme cold pattern
as the week progresses...eroding the western noam ridge and even
showing a brief surge in upper heights and temperatures over the northestern US
along about Thursday...ahead of another cold front that should
pass late in the week. However the parent upper low is made to
remain over hudson's Bay and even drops south in
time...reinforcing the troughing over the northern US by weeks end.
This would favor a return of temperatures near or perhaps a bit below
normal...but not the extreme cold we have been experiencing.
Aviation /12z Sunday through Thursday/...
Main change for 12z tafs was to add a line for snow showers
across the central and eastern sites. Already had snow showers
in the west.
A decent day in store for the area today...as high pressure
builds into the state. Looking at sunny skies with VFR
Some snow showers later tonight...as a fast moving cold front
moves southeast from the upper Great Lakes area.
A few rain and snow showers for Monday...mainly across the
north and west.
Some rain and snow showers for Tuesday into early Wednesday...as
low drops southeast from the Central Plains of Canada.
Monday...chance of light rain /light snow early/ across the
western half with MVFR reductions. VFR southeast.
Tuesday...chance of light snow/rain...mainly across the northwest half
with MVFR reductions. VFR southeast.
Wednesday-Thursday morning...mainly VFR...as high pressure builds across
Thursday afternoon-night...a gradually decrease to MVFR with
scattered rain showers...as a cold front moves eastward.
near term...la corte
short term...la corte
long term...la corte/tyburski