Area Forecast Discussion
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FXUS61 KPBZ 010534
Area Forecast Discussion
National Weather Service Pittsburgh PA
134 AM EDT Sat Oct 1 2016
Upper level low pressure will continue to produce bands of showers
across the region into the weekend.
.NEAR TERM /THROUGH TONIGHT/...
The semi-resident upper low will continue to reside in the Ohio
Valley through the near term forecast period. Hi-res models really
are failing to handle ongoing bands of precipitation over the area
very well early this morning, however upstream radar trends
combined with the redevelopment and persistence of an upper jet
streak entrance region over the area should allow for a secondary
expansion of showers over the area. This will occur even as drier
air on water vapor imagery starts to come over more of the region
through the night.
As the upper low starts to meander northeastward a bit through the
day on Saturday, colder mid-level temperatures will allow for
steeper lapse rates to favor additional shower formation over the
northwestern CWA, while continued upper divergence over the
eastern CWA will favor development there. As such, nothing less
than chance PoPs have been included in the forecast for Saturday.
However, due to more likelihood of breaks in the clouds as well as
the slow trending of low level flow from the east to southwest
during the day, temperatures should go up several degrees from
those seen on Friday.
The upper low will continue to migrate northeastward tonight
allowing for deeper layer southwesterly flow to become
established. This will allow for the dry slot to make serious
inroads into the CWA, which means PoPs will trend down decidedly
overnight into Sunday morning. Fries
.SHORT TERM /SUNDAY THROUGH MONDAY/...
Very slow movement to closed low as it shifts toward New England
by Sunday night, followed by rising heights Monday as a ridge
begins to build across the region. Scattered showers will remain
across much of the region through Sunday, then mainly toward I-80
Monday as low exits. Temperatures will average above normal
through the period, as overnight lows will be well above the
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A ridge of high pressure will be over the region through Thursday
with dry conditions and mild temperatures. A weak frontal boundary
will approach Friday, and chance POPs were introduced.
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
Weakening surface flow will be evident over all sites through the
night. Combined with scattered showers, this should allow CIGs to
trend downward through the night, however VIS restrictions should
be minimal and fairly local. Drier air will move into the area on
Saturday in the mid-levels, however colder air aloft will mean
showers should redevelop with the upper low drifting nearby. Even
still, conditions should largely improve to VFR at most sites.
.OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...
Brief IFR/MVFR restrictions will linger into Monday when the
upper level low finally departs.