Scientific Forecaster Discussion
fxus61 kpbz 201512
Area forecast discussion
National Weather Service Pittsburgh PA
1012 am EST Wed Nov 20 2019
dry conditions and a warming trend is expected before
precipitation and cooler conditions return at the end of the week.
Cooler temperatures will continue through the weekend with showers
Saturday afternoon transitioning to snow overnight.
Near term /until 6 PM this evening/...
the update at 10am focused mainly on updating the sky cover grids for
current satellite trends. The 12z sounding shows a Stout inversion at
800mb that will be tough to mix out completely. However, with
southeast Ohio already clear, and with breaks showing up in southwest
PA/northern WV, am fairly optimistic that most locations will see at
least a little sunshine at some point today. Fog is starting to mix
out as well and should generally disappear by midday. Temperatures
are in good shape, with values remaining below normal in the
continued northwest flow.
Short term /6 PM this evening through Friday/...
dry conditions will continue on Thursday with increased temperatures
(slightly above average) as southwesterly flow picks up ahead of the
next system approaching from the west.
Precipitation chances will increase Thursday evening with the best
chances at this time looking to be late Thu night- Fri
morning...ending Friday afternoon as drier air quickly invades behind
the front. Overnight temperatures will be relatively mild with
increased mixing and warm air advection overnight ahead of the cold front. After
frontal passage temperatures during the day on Friday will be fairly
stagnant or slowly drop over the course of the day in the wake of the
Long term /Friday night through Tuesday/...
below average temperatures will return for the weekend with showers
returning Saturday afternoon...and changing over to snow overnight
as the next low pressure system impacts the region. Dry conditions
expected for most of Sunday and into next week as high pressure
builds across the forecast area.
Aviation /15z Wednesday through Sunday/...
IFR/MVFR conditions will prevail through at least mid-morning as
low-level moisture is trapped under a building ridge. Daytime mixing
and dry air will help to lift and break up the clouds gradually
through the day. Most sites should have ceilings lift to VFR heights
by early afternoon, if not a bit sooner.
The sky will clear out, leading to mostly VFR conditions overnight.
Fog development is possible overnight given low-level moisture and
low wind initially, but southerly wind should pick up towards dawn,
limiting fog development. Have left out of taf package due to low
confidence at this point.
more widespread restrictions are expected with a late-week frontal