Area Forecast Discussion
Issued by NWS
FXUS61 KPBZ 281837
Area Forecast Discussion
National Weather Service Pittsburgh PA
237 PM EDT Fri Oct 28 2016
Dry weather and slightly warmer low temperatures are expected
tonight. Saturday will be much warmer with increasing clouds. A
cold front will bring rain chances mainly Saturday night and
.NEAR TERM /THROUGH TONIGHT/...
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 surface ridge shifts to the
east and the next system approaches. Thus, expect temperatures to
stall just above seasonal numbers for lows.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Low level southwest flow will push a warmer air mass back into our
CWA on Saturday, with high temperatures some 20 or more degrees
warmer than today. Upper flow will show a more zonal trend, which
will hinder the initial approach of the next front from the north.
The day will start with sunshine, but clouds will be on the
increase in the warm advection pattern. A few showers may begin
to show up near I-80 by sunset.
The front will get its main push later Saturday night and Sunday
as a shortwave crosses the Great Lakes and the Ohio Valley. Kept
the idea of likely PoPs for much of the area with the frontal
passage. Moisture is decent with PWAT values peaking around 1.25
inches, but overall support for lift, especially aloft, is not
overly impressive. Thus, precipitation is not expected to be
heavy. Models do indicate some instability Sunday afternoon in
areas from Pittsburgh south, and added thunder chances as a
result. Wind shear is marginal at best, and given weak instability
overall, severe weather is not anticipated. Above normal
temperatures will continue.
A few showers will linger across the south Sunday evening as the
front finishes crossing the area, with decreasing clouds late.
With still somewhat zonal flow behind the boundary, temperatures
will return to seasonable levels.
.LONG TERM /MONDAY THROUGH THURSDAY/...
Dry weather is forecast through Wednesday as mid level ridging is
in place. 500 mb heights will slowly rise through the period,
indicating a return to above normal temperatures. The next front
is expected Thursday or Thursday night, and model timing issues
remain. Kept PoPs low as a result. Right now, Friday appears dry
with a return of seasonable temperatures.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR will prevail through the rest of the period with light wind
shifting from WNW to SE as the surface ridge shifts to the east.
Strengthening low level jet tonight will bring the risk for wind
shear so, this has been included in several of the terminals
through sunrise. Expect little more than high clouds until the
approach of the next system, late Saturday night/Sunday.
.OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...
General restrictions are again possible with a Sunday cold front.