Scientific Forecaster Discussion
fxus61 kctp 221936
Area forecast discussion
National Weather Service State College PA
336 PM EDT sun Sep 22 2019
an area of high pressure centered off the mid Atlantic coast
will drift east and allow a cold front to approach Pennsylvania
from the Ohio Valley. The front will be followed by a brief cool
down Tuesday and Wednesday, followed by another cold front for
Thursday and Friday.
Near term /until 6 am Monday morning/...
high clouds are thinning out as they top the eastern ridge,
leading to a hazy warm and increasingly humid day for the
The main change was to downplay the already low chances for
showers this afternoon. The model pops are quite low and the
various cams show little more than a stray shower or two. I
chose the more optimistic dry forecast for the afternoon.
Pwats will rise into the 1.25" to 1.50" range marking the
increase in moisture ahead of the approaching cold front. While
this could help fuel a pop-up shower or storm, warm 700 mb temps
and continued warm advection aloft should cap/negate most or
all deep convection.
Any very isolated showers that manage to form will fade with
loss of heating. The overnight will be unseasonably warm and
humid with overnight lows averaging 15-20 deg above normal.
Short term /6 am Monday morning through 6 PM Monday/...
models agree in pushing a cold front through the region
Monday/Monday evening. This system will likely be accompanied by
a round of mainly light showers. Models create very little
instability, suggesting we will be rather cloudy (cooler) ahead
of the front. Basin average quantitative precipitation forecast will be generally a tenth of an
inch or less, though scattered amounts of around 0.25 of an
inch are likely, especially across the southeast half of PA where a few
thunderstorms could occur.
Long term /Monday night through Sunday/...
the front will move through the region rather quickly with a
return to fair and slightly warmer than seasonable weather
Tue/Wed. High pressure should build southeast from the grt lks
during the middle of the upcoming week, followed by a weak cold
front Thursday that will generate only very light quantitative precipitation forecast and
showers that will be isolated to scattered in coverage.
Aviation /20z Sunday through Friday/...
all terminals are VFR and will continue into the evening. A
stray afternoon shower is possible in vicinity of khgr/kipt
corridor, but impacts if any will be brief.
A cold front will bring increasing chances of showers into the
region during the day Monday, with MVFR conditions likely by mid
to late morning over the western and northern higher elevation
Elsewhere terminals will remain mainly VFR but with brief
restrictions in the scattered showers.
The cold front will clear the southeastern airspace by evening ushering
in drier air and improving conditions.
Tue...am MVFR cigs possible wrn 1/3.
Wed...patchy am fog northern valleys.
Thu...cold front with local restrictions in showers and possible
Friday...no sig wx.
autumn officially arrives at 3:50 a.M. EDT, on Monday, sept. 23.
near term...la corte