Area Forecast Discussion
Issued by NWS State College, PA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 010943
Area Forecast Discussion
National Weather Service State College PA
443 AM EST Thu Dec 1 2016
A large and deep storm system will move slowly through Quebec over
the next couple of days, setting up a prolonged period of cool
northwest flow over the local area. High pressure will build in
for a brief time Sunday before the next frontal system approached
early next week.
.NEAR TERM /THROUGH TONIGHT/...
Rain has come to an end with the front that moved east of the area
shortly after midnight. We will transition into a cooler west-
northwest flow pattern today with the usual cold season strato-cu
clouds and scattered showers of rain or snow that will mainly
favor the NW and Laurel Highlands. The low level wind field will
initially be mainly out of the west which normally confines the
best lake enhanced showers over southern NY or extreme NW Pa. I
leaned closer to HRRR POPs with the meso model confining most showers
very close to the lake during the day.
The wind is expected to become a bit more NWLY overnight which
will help bring precipitation more into my NWRN zones. However the
upstream air is only marginally cold and BUFKIT shows limited low
level instability of the air passing over the lakes so I am not
too excited about the prospects for any kind of significant lake
.SHORT TERM /FRIDAY/...
The cold NW flow will remain air in place for Friday, but again
the cold air is unimpressive so NW snow shower activity is not
expected to amount to more than nuisance amounts. With high temps
expected to be above freezing, most areas will ave a hard time
making any snow stick at all.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Most areas will be precipitation free Sat-Mon except the
northwestern areas where some the over-lake trajectory will bring
the usual areas the familiar kind of lake effect showers that
happen so often in the cool season.
Sunday looks like we will see a brief respite as high pressure
moves over the state. By late Sunday into the overnight, a period
of light snow is possible as a northern stream shortwave races
through the region with a burst of warm advection. QPF looks to be
on the order of a tenth of an inch or less, but occurring
overnight many places could see their first coating of snow of the
By midweek there is decent agreement in bringing the SW US upper
low up through the OHIO Valley as a shearing out shortwave and
diffuse surface low. Unless cold air damming traps enough chilly
air in the low levels to make for some freezing rain, the precip
type with this midwest system looks to be mainly rain.
The end of the week brings some model disagreement with the
GFS/GEFS being faster than the ECMWF with the next upper trof and
frontal system. The end of the extended has just a chance of
showers given the lack of confidence.
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --Surface ridging and arrival of drier air has brought improving
conditions across Central Pa early this morning, with mostly clear
skies noted over the eastern half of the state at 09Z. Further
west, residual low level moisture ascending the Appalachian Mtns
continues to result in MVFR stratocu at KBFD and KJST. Model
soundings and upstream observations support mainly MVFR CIGs at
KBFD/KJST through dawn and predominantly VFR elsewhere.
Very little change indicated during the daylight hours later
today, with persistent MVFR CIGs over the upslope region from KBFD
to KJST and possibly extending into KUNV/KAOO. A downsloping/drying
west wind should ensure VFR conds further east. After a brief lull
in the wind speeds this morning over Eastern Pa, expect a rather
gusty daytime, as stronger flow aloft begins mixing to ground
level. Bufkit soundings support frequent gusts to around 25kts
after about 14Z.
A WSW wind flow should keep lake effect snow showers mainly north
of the border today. However, latest model data suggests a slight
shift in the wind could cause the lake effect snow showers to move
from upstate NY into NW Pa tonight. Thus, IFR vis reductions
appear possible at KBFD tonight.
Fri-Sat...MVFR CIGS and ocnl SHSN/IFR vis possible KBFD/KJST.
Sun...Slight chance of light snow/reduced vis at night.
Mon...No sig wx expected.
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NEAR TERM...DeVoir/La Corte
SHORT TERM...La Corte
LONG TERM...La Corte