Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
1247 am EDT Tue Oct 25 2016
high pressure will bring dry and cool conditions tonight into
Wednesday. Low pressure will bring showers back into the forecast
Wednesday night through early Friday.
Near term /through today/...
general northwest flow will continue through the day today with
some indications of a bit of a multi-lake fetch enhancing moisture
flow toward the northern portions of the area. Model soundings and
hi-res solutions both favor the continuation of a stratocumulus
deck generally from Pittsburgh northward and developing into the
ridges through the morning with diurnal enhancement likely toward
early afternoon on Tuesday. A shower or two will be possible in
the far northern reaches of the area due to very unstable low
level lapse rates and some indications of saturation depth through
the stratocumulus layer. Otherwise, the area remains dry through
the day today with over-lake fetch decreasing late. This should
start to allow for the dissipation of stratocumulus by that
With clearing over Ohio and decreasing winds due to surface high
pressure advecting southeastward through the period, radiational
cooling should be fairly efficient. As dewpoints linger near
freezing, this should allow for some frost development. The frost
advisory will thus be continued through morning in these areas.
Short term /tonight through Thursday night/...
conditions are expected to be clear and cold under high pressure
Tuesday night. Much of Wednesday will be dry but with increasing
clouds as a warm front approaches in advance of deepening Great
Lakes low pressure. Shower chances will increase Wednesday night,
with likely pops Thursday as system crosses the upper Ohio Valley.
The mid level system will close off over New England for a time,
keeping cold northwest flow across the region into Thursday night
with scattered showers.
Long term /Friday through Monday/...
brief ridging will dry out the region Friday afternoon, but
another trough will already be approaching from the west for
Saturday. Unsettled weather and cooler than seasonal average
temperatures will hold for the weekend into early next week, as a
broad trough will remain over the eastern Continental U.S.. in general,
followed close to the superblend guidance for construction of the
Aviation /06z Tuesday through Saturday/...
VFR conditions seem most likely to continue at all sites through
the period. Some lake-induced showers may wander as far south as
kfkl and kduj for a time toward morning, making some MVFR
conditions a possibility, however they shouldn't linger.
Stratocumulus should also start to scatter out from the southwest
by afternoon with all sites likely to see nearly clear conditions
by evening on Tuesday. Fries
Outlook /Tuesday through Friday/...
the next chance for general restrictions will late Wednesday into
Thursday as the next disturbance crosses the region.
Ohio...frost advisory until 9 am EDT this morning for ohz039-048-049-
WV...frost advisory until 9 am EDT this morning for wvz004-012.