Scientific Forecaster Discussion
fxus61 kpbz 170126
Area forecast discussion
National Weather Service Pittsburgh PA
926 PM EDT Wed Oct 16 2019
much colder air will overspread the region tonight, keeping
temperature below average through Friday. Rain chances return to
the region early next week.
Near term /until 6 am Thursday morning/...
no changes were needed for the eve update as low pressure is digging
east of the Great Lakes with continued light showers in the cold
cyclogenesis is occurring with this low pressure system as evident
via the negatively tilted with height trough structure and increasing
pressure gradient. Wind will be a topic to focus on this evening and
overnight as strong winds mix toward the surface. This will be
especially prevalent in the higher elevations of Tucker and Garrett
counties, where gusts to 50 mph will be possible. A Wind Advisory
has been issued for those areas.
Additionally, thermal profiles in the highest ridges of Tucker County
may support a brief period of snow showers tonight, although
confidence is low in regard to the presence of ice crystals
sufficient for snow growth. Tonight may wind up with a period of
prolonged cold drizzle in these areas in lieu of snow showers. If
snow does occur, however, warm ground will prohibit a noteworthy
Short term /6 am Thursday morning through Friday night/...
nwly low-level flow and cold-air advection will maintain a fetch
from Lake Erie and persistent stratocu/lake-enhanced showers in the
ridge zones and I-80 corridor on Thu/Thu night before high pressure
builds in for Fri.
Cloud cover will linger into Fri until mid-level warm-air advection
limits the depth of instability and helps to erode the stratocu. As a
result, maxima both Thu and Fri will be limited.
Long term /Saturday through Wednesday/...
an amplifying upper-level ridge will lead to dry weather for the
better part of the weekend, along with a warming trend. Maxima will
reach the mid to upper 60s Sat and sun, several degrees above
Considerable agreement exists on the general presence of a strong
upper-level low in the plains early next week. The expectation is for
the system's cold front to approach the region on Mon, with
increasing chances for showers and gusty wind as it crosses.
Main changes to medium-range blends included an increase in pops for
the Mon system given the general improvement in frontal timing.
Aviation /02z Thursday through Monday/...
scattered showers supported by shortwave support rounding the base
of a deep, upper trough will result in the deterioration to MVFR
restrictions this evening.
Cold advection in nwly flow will then support steepening lapse rates
this tonight will support widespread MVFR restrictions in a
persistent stratocu deck and scattered showers through the period.
This will also support the mixing down of strong wind to the surface,
with gusts ranging to 20-25 knots.
restrictions are possible through Thursday under northwest flow and upper
Maryland...Wind Advisory until 2 PM EDT Thursday for mdz001.
WV...Wind Advisory until 2 PM EDT Thursday for wvz514.