Area Forecast Discussion
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FXUS61 KPBZ 271502
Area Forecast Discussion
National Weather Service Pittsburgh PA
1102 AM EDT Thu Apr 27 2017
A very warm day will be interrupted by showers and storms with a
.NEAR TERM /THROUGH TONIGHT/...
the late morning update featured adjustments to POPs based on
the latest radar and high res model trends.
A weak cold/occluding front will is triggering showers and
storms over areas west and south of Zanesville. These will
progress eastward and are expected to intensify as the boundary
layer destabilizes this afternoon, especially over areas east of
a Dubois to Parkersburgh line where peak heating will drive
temperature toward the mid 80s.
Despite impressive deep layer shear, the area has been limited
to a "marginal" severe risk. This seems appropriate given
instability limitations imposed by sub 60 dewpoints and a plume
of warmer mid level air advecting along the advancing front.
Should storms develop and organize, the primary severe threat
still looks to be from damaging wind via short bowing segments.
Passage of the front will herald diminished convection as the
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Dry weather returns Friday with high pressure. Any cooler air
behind today`s front will be quickly ejected to the north as
strong warm air advection takes over.
Eastern ridge will try to build late Friday, but will be shunted
by a series of upper level waves which will ride over the top of
the rising heights. These wave will bring showers and storms
back to the area late Friday night and Saturday. Seeing
discrepancies in models solutions on Saturday with the position
and timing of the shortwaves. Have leaned toward a more
northern track, which complies with slowly rising 500mb heights
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
An active pattern is figured for the remainder of the weekend
into early next week. A few shortwaves will cross in continued
moist southwest flow along the front of a broad trough, leading
to rain chances again on Sunday. Timing remains tricky, but
Saturday night currently looks to be the period with the lowest
coverage in the warm sector. Temperatures remain above normal.
The trough lifts out as a closed upper low into the Great Lakes
by Monday, pushing a fairly strong boundary across us. Given
system strength, the amount of moisture, and a possibly negative
tilt to the upper trough, strong storms appear possible. Behind
this system, quieter weather and seasonable temperatures are
expected into the middle of next week.
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR conditions expected much of the day. Winds will pick up out
of the south and gust to 20 to 25 knots once mixing gets going.
Timing for the frontal passage will be between roughly 18Z and
02Z, with showers and thunderstorms along and ahead. Expecting a
brief period of MVFR showers with VCTS, with exact timing still
a bit uncertain, temporary IFR possible in any downpours.
Stronger wind gusts are also possible in the strongest storms.
Behind the front, winds will diminish and MVFR ceilings will
Occasional restrictions are possible this weekend along a
stalled frontal boundary. Better restriction chances arrive with
a strong cold front Sunday night into Monday.