Scientific Forecaster Discussion
fxus61 kpbz 152222
Area forecast discussion
National Weather Service Pittsburgh PA
522 PM EST Fri Nov 15 2019
dry conditions are expected through the weekend with precipitation
chances returning early next week. Below normal temperature will
prevail for much of the next week.
Near term /until 6 am Saturday morning/...
530pm update...minor tweaks to temps and sky based on latest
satellite imagery/sfc obs. Expect more rapid cooling in cloud-free
areas, with cooling slowed as clouds overspread a given locale ahead
the frontal passage.
A weak cold front will sag southwards across the area later through
the night, with increasing cloud coverage after frontal passage due to moisture
stuck beneath the Post-frontal inversion. With limited moisture and
a lack of upper support, precipitation is unlikely to develop,
though cannot rule out brief sprinkles north of I-80 as nw'ly flow
gains moisture from the lake. Regardless, feel potential is low
enough at this time to drop previously mentioned slight chance pops.
Increasing sfc high pressure and subsidence aloft will begin to erode
the Post-frontal stratocu deck Saturday morning.
Short term /6 am Saturday morning through Sunday night/...
drier air will filter back into the region on Saturday as high
pressure builds to the north. Cloud cover will continue dissipating
through the morning hours, resulting in mostly sunny skies for the
afternoon. With cooler/drier air and light wind, Saturday night will
be the coolest of the period. Weak warm air advection will develop
Sunday as the sfc high shifts to the northeast and southerly flow
increases ahead of the next incoming trough.
Long term /Monday through Friday/...
mostly dry weather will continue into Monday morning before a series
of shortwaves traversing the broad econus trough will provide rain
chances Mon-tues with lingering lake-enhanced showers into Wed.
Details remain murky at this time, so have maintained chance/slight
chance pops for that period.
Brief shortwave ridging Wednesday will quickly shift east ahead of a
deepening trough that will impact the region through the end of the
week. A sfc low is progged to move from the northern plains/Midwest
Ontario/Quebec during this period, with increased precipitation
chances along and ahead of a passing cold front.
Beyond a brief warm up Wednesday under the shortwave ridging that
will nudge temperature to near normal, the rest of the period will
remain below normal under the influence of econus troughing.
Aviation /22z Friday through Wednesday/...
MVFR stratus will continue to plague fkl this eve and that cloud
field is expected to sag southward with the supporting cold front as
low pressure completes passage across ern Canada. Sfc high pres
sliding acrs Quebec will veer the wind and with increasing subsidence,
diminish the stratus and support VFR by early Saturday.
the next chance for restrictions is expected Monday with the advance
of low pres acrs the Great Lakes.