Scientific Forecaster Discussion
fxus61 kctp 161555
Area forecast discussion
National Weather Service State College PA
1155 am EDT Mon Sep 16 2019
a weak stationary front overhead will get nudged off to our
south today and early tonight. High pressure will build in from
the north and bring a very long stretch of dry weather.
Near term /until 6 PM this evening/...
nearly stationary surface frontal boundary extended from the northwest
mtns of PA to the Lehigh Valley at midday. A weak wave of low
pressure riding east-southeast along this boundary will provide some
slightly enhanced low level and limited Theta-E convergence/uvvel,
but enough to form some small/brief light showers that will be
falling from high-based strato cu and low-end Alto cu.
Rainfall will be barely enough to wet the ground in most places.
The greatest amount of sunshine and warmest temps (lower 80s) will
be across the south-central counties of the state.
The axis of the most numerous showers will drop southward
along and to the south of the Route 322 corridor during the
afternoon. Last several runs of the hrrr represent the size and
areal coverage of the showers the best today, while the hrefv2
is way overdone in coverage this afternoon - being and ensemble
with slight variations in placement of the small convective
The northern tier will be drying out then as the wind GOES
decidedly north to NE. Coolest Max temps, holding in the upper,
will be over the northern and central zones.
Short term /6 PM this evening through 6 PM Tuesday/...
the front should be south of the state around sunset, but
showers could linger for much of the night over the south. The
clearing expected across the north will lead to temps getting
down into the 40s and the requisite fog in the valleys of the
north. The fog could linger into the middle of the morning in
the deeper valleys. Overall, though, it will be a dry, sunny
day. Dewpoints will be in the 40s and lower 50s. Maxes in the
u60s-m70s will be spot on normal.
Long term /Tuesday night through Sunday/...
a large upper level ridge will build over the Great Lakes which
will dominate the weather pattern through the week. This should
keep central PA dry through the week, perhaps until Sunday.
Temperatures near normal at first should rise well above normal
as the ridge pumps up and slides eastward a little.
Aviation /16z Monday through Friday/...
a weak area of low pressure and associated frontal system will
support mid level cloudiness across central PA today. Isolated
to scattered mainly light rain showers will drift from
northwest to southeast across the airspace through the day.
Generally VFR conds will prevail, though a few of the showers
could be heavy enough for a few minutes of high-end MVFR vsbys
and cigs to the south of a kduj to kunv and kmdt line through
Post-frontal, low level moisture combined with orographic lift
is likely to result in MVFR cigs during the PM hours across the
Tue-Fri...am valley fog possible central/northern PA, otherwise
no significant weather expected.