Scientific Forecaster Discussion
fxus61 kpbz 182005
Area forecast discussion
National Weather Service Pittsburgh PA
405 PM EDT Wed Sep 18 2019
a strengthening ridge of high pressure will provide dry weather and
above average normal temperatures into the weekend.
Near term /until 6 am Thursday morning/...
high pressure will continue to provide clear and quiet weather
tonight. Once again, the air mass should remain too dry to support
fog formation, even in valley locations in most cases.
Short term /6 am Thursday morning through Friday night/...
an upper ridge axis should slowly shift from the middle Ohio Valley
to our region by Saturday morning. Dry weather and temperatures
above the climatological average are expected to continue. Relative
humidity is forecasted to increase Friday as deep southwest flow
Long term /Saturday through Wednesday/...
models continue to slow down the approach of a western US
trough/cold front this weekend, which is not surprising given the
strong ridge in place. After a dry and warm Saturday, with slowly
increasing humidity, most of Sunday should feature quiet weather as
well given the slower trend of the approaching front. Will still
allow for low pops in the northwestern County Warning Area later in the afternoon.
The most favorable period for precipitation still appears to be
Sunday night and Monday with the frontal passage.
A return to dry weather is currently expected for Tuesday and
Wednesday. With the break down of the upper-level ridge, temperatures
may fall below the climatological average.
Aviation /20z Wednesday through Monday/...
VFR and an Ely wind component will continue through Thursday as sfc
high pres remains in place ovr the nern U.S. The dry airmass will
also inhibit fog formation with exception for isold areas of steam
fog, which may affect fkl.
no widespread restrictions expected over the next few days.