Area Forecast Discussion
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FXUS61 KPBZ 160149
Area Forecast Discussion
National Weather Service Pittsburgh PA
849 PM EST Wed Feb 15 2017
The arrival of colder air return snow shower chances to the
forecast through Thursday. High pressure will then build in for
the beginning of the weekend with drier and warmer conditions
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
430pm update...minor adjustments to PoPs overnight in line with
current radar imagery and latest hires model guidance. If
current guidance is correct, it appears two main bands should
develop this evening, one over the I-80 corridor, and one over
portions of Ohio extending into SW PA. The stronger of the two
will remain over the north closer to the lakes. Upslope snow
over the ridges will also get cranking soon as the coldest air
reaches those locations. Temperatures have been updated with a
blend of hires guidance.
A deepening upper low projected to cross into New York this
evening will reinforce colder air across the area. The
combination of colder air with increasing moisture in the low
levels will assist in generating more snow showers, especially
across the favorable upslope terrain. Model soundings depict
steep lapse rates through the snow growth zone with sufficient
moisture overnight across the ridges of WV and MD. Thus,
confidence has increased in issuing an advisory for snow
overnight. Given the quick breakdown of the inversion height as
high pressure is progged to build late tonight, snow
accumulation should overall remain below advisory criteria
Temperatures will gradually fall through the period
and reach near seasonal values.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Building high pressure should end the snow showers later on
Thursday and keep temperatures slightly cooler than average. Dry
and relatively warmer weather is expected Friday while a ridge
develops over the southeast CONUS. Temperatures will rise to
well above normal levels on Saturday as warm advection
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A weak shortwave tries to undercut the ridge across the
Tennessee Valley Saturday night. Still think that most
precipitation from this feature will remain off to our south,
and have continued slight chance PoPs where moisture and lift
will be limited. The ridge then reestablishes itself through
Monday. A weak shortwave may succeed in knocking down the ridge
to some degree by Tuesday, leading to the next decent rain
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --VFR / high MVFR through the period under cold northwesterly
flow and scattered snow showers. Intermittent IFR vis
restrictions will be possible at times mainly before midnight
during periods of more moderate snow. Exceptions will be KFKL
and KDUJ, where IFR snow showers will be possible overnight.
Gusty winds will slowly diminish toward daybreak. As low
pressure off the New England coast moves east Thursday, gradual
improvement to VFR can be expected by late day.
A weak disturbance may bring restrictions Friday morning,
otherwise the next chance for widespread restrictions will be
with a Tuesday cold front.
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MD...Winter Weather Advisory until 10 AM EST Thursday for MDZ001.
WV...Winter Weather Advisory until 10 AM EST Thursday for