Scientific Forecaster Discussion
fxus61 kpbz 230118
Area forecast discussion
National Weather Service Pittsburgh PA
918 PM EDT sun Oct 22 2017
a cold front will return rain to the area Monday and Monday
night. Low pressure will maintain shower chances and cool
temperatures through mid week.
Near term /through Monday/...
no major changes for the late evening update. Previous...clouds
should continue to increase tonight ahead of approaching low
pressure. The low is progged to track through the Ohio Valley to
the lower Great Lakes Monday, dragging a cold front through the
region. Maintained the gradual increase to categorical pops from
west-east as the front approaches. A tightening pressure gradient
should also result in gusty southeast wind especially across the Laurel
Highlands and the higher terrain of WV/Maryland Monday. Mentioned
gusts up to 40 mph for those areas.
Temperatures should continue to average 10 to 15 degrees above
Short term /Monday night through Wednesday/...
while low pressure shifts north over Lake Huron Monday night,
its cold front should race to the east. Heaviest rainfall should
have moved out of the region by the early morning hours. Overall
rainfall totals have come in slightly lower on 12z model runs,
but rain is still expected to be around an inch at most
locations. Instability along the front is lacking, and have kept
any mention of thunder out of the forecast.
Showers Tuesday and Tuesday night will be of a scattered nature
from an upper low remaining over the northern Great Lakes. The
low itself begins making eastward progress Wednesday, and have
added some likely pops along the Interstate 80 corridor
Wednesday afternoon. Colder air will continue to enter the
forecast area, with temperatures near normal Tuesday and Tuesday
night. Wednesday should be the coldest day of the week.
Long term /Wednesday night through Sunday/...
the chance for showers will come to an end late Wednesday night
as the upper low moves east. With temperatures continuing to
cool off, cannot rule out a couple of snowflakes across Garrett
or Preston counties. Thursday and Friday should remain cool and
dry. While the European model (ecmwf) and GFS have general agreement of low
pressure dragging a cold front to the area for the weekend, the
models have shown little consistency in the speed of the front
and when any precipitation would arrive. Have stuck close to the
superblend for this portion of the forecast.
Aviation /01z Monday through Friday/...
VFR conditions will continue into Monday as high pressure
erodes in advance of midwestern low pressure. Expect condition
deterioration to low-end MVFR through the afternoon as that
trough advances and spreads rain over the region.
periodic restrictions should continue through Wed with the
region under upper troughing.