Scientific Forecaster Discussion
fxus61 kpbz 210920
Area forecast discussion
National Weather Service Pittsburgh PA
420 am EST Tue Nov 21 2017
a cold front will bring the next chance for precipitation
tonight. Dry weather and below average temperature are expected
for the remainder of the week.
Near term /until 6 PM this evening/...
warm advection, on southerly flow and sunshine, will push high
temperature a few degrees above the seasonal averages today.
Short term /6 PM this evening through Thursday/...
cold front will quickly swing through the area this evening and
into the overnight hours. Model are showing sufficient upper
level support and low-level forcing to continue with likely
pops, mainly over the northern half of the region. The cold
airmass behind the front does not look deep enough to sustain a
very long period of Post frontal snow showers. Forecast
soundings are showing saturation levels dropping quickly, well
below the dendritic snow growth layer. Minor snow accumulations
are possible, but should be limited mainly to the I 80 corridor
and ridges. Less than an inch is anticipated in those areas.
High pressure will then ensure a dry midweek and Thanksgiving
Holiday, with sub average temperatures.
Long term /Thursday night through Monday/...
ensemble forecasts are showing the next cold front dropping
through the area on Saturday, followed by the next trough
setting up over the eastern conus, which will hold into the
beginning of next week. Cold surface high is expected to build
back in late Sunday into Monday.
Aviation /09z Tuesday through Saturday/...
VFR through much of the day with restrictions at fkl and duj
late tonight as a front quickly crosses. Winds will increase
ahead of the front as the pressure gradient increases with wind
gusts around 20 kts.
subsequent cold advection is expected to maintain MVFR cigs
into Wednesday, but improvement can be expected as the day
progresses. The next chance for restrictions is forecast with an
early Saturday cold front.