Area Forecast Discussion
Issued by NWS -- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KPBZ 281558
Area Forecast Discussion
National Weather Service Pittsburgh PA
1158 AM EDT Fri Oct 28 2016
Building high pressure will slowly decrease cloud cover and keep
the area cool and dry today. Warmer temperatures and increasing
precipitation chances return Saturday.
.NEAR TERM /THROUGH TONIGHT/...
Clouds have been slow to clear in lingering northwest flow this
morning. Still think that overall coverage will diminish as enough
mixing of dry air takes place to lift and scatter out the clouds
with high pressure in place. Still, do not think we will see
enough sun and warm advection will remain weak, so today`s highs
were kept just below normal.
Clearing skies and light wind should help temperatures to fall early,
but strong warm advection aloft should slow the cooling by the
latter half of the night as the next system approaches. Thus,
temperatures were generally kept above seasonal numbers.
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
Upper level flow will become zonal on Saturday, but we will still
see an influx of warmer air, as the lower and mid-level flow turns
to the southwest. With a lack of a strong push from the upper
levels, the next system will struggle to make much southward
progression late Saturday. Decreased the southward intrusion of
PoPs late Saturday and Saturday night. With the aforementioned
warm air advection, Saturdays highs will be close to 10 degrees
Surface front will finally begin to push southward late Saturday
night and Sunday as the main shortwave crosses the Great Lakes
and eventually the Upper Ohio Valley. Showers will spread over the
entire region Sunday, with the surface boundary reaching the
Mason-Dixon line by afternoon. Upper level support remains weak,
so would think that shower activity would be scattered.
With clouds and rain, temperatures on Sunday will return to near
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The upper Ohio Valley will be on the top side off strengthening mid
level ridging into Wednesday, with above average temperatures. The
ridge will retrograde mid week, allowing a frontal system to slide
south of the region Thursday. With timing of this system in
doubt, slight chance POPs were included.
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
MVFR conditions should gradually improve to VFR as high pressure
briefly builds overhead and we lose the moisture fetch off of Lake
Erie. VFR will then prevail through the rest of the period with
light wind shifting from WNW to SE. Strengthening low level jet
tonight will bring the risk for wind shear. So, this has been
included in several of the terminals through sunrise.
.OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...
General restrictions are again possible with a Sunday cold front.