Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
1226 PM EST Friday Nov 21 2014
cold high pressure will build in today. Widespread shower chances
return with Sunday evening low pressure.
Near term /until 6 PM this evening/...
high pressure will build in behind an exiting shortwave today. Terrain enhanced
flurries north and east of pit should decreases this afternoon...though cumulus rule
indicates cold air cumulus/SC will continue through much of the day. Morning radiosonde observations
spprt high temperatures ranging from the lower to upper 20s across the region.
Short term /6 PM this evening through Sunday/...
big change in the overall pattern this weekend as strong warm air advection gets
cranking on Saturday and continues through the weekend. Showers
could develop Saturday afternoon across the northern half of the
area along a passing warm front. Most of the upper level support
and deep moisture will be across the north...so will place the
highest probability of precipitation there. Noticeably warmer temperatures on Saturday.
A series of waves will move through Saturday night and
Sunday...keeping in the risk for scattered showers through the
Long term /Sunday night through Thursday/...
widespread showers will quickly move Sunday night. Warm pattern
will continue through early Tuesday...when the next front will
bring colder air to the region for the remainder of the long term.
Aviation /18z Friday through Wednesday/...
expect MVFR ceilings to hold on in northwest flow at kduj until after
sunset while VFR ceilings break out elsewhere as surface ridge moves
east across the lower Ohio Valley. VFR into Saturday with only an
increase in middle deck Saturday morning.
Outlook.../Saturday night through Wednesday/...
possible MVFR to IFR conditions Sunday night into Monday as the
next storm system approaches.