Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
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FXUS61 KCTP 271814
Area Forecast Discussion
National Weather Service State College PA
214 PM EDT SAT AUG 27 2016
A large ridge of high pressure will reside over Pennsylvania
through midday Sunday bringing very warm and mainly dry weather.
A weak cold front will push southeast across the state Sunday
night into Monday morning. Scattered showers and thunderstorms are
possible ahead of the front. Another period of warmer than normal
and mainly dry days will follow for Monday...Tuesday...and the
first part of Wednesday.
.NEAR TERM /THROUGH TONIGHT/...
Partly cloudy skies through Central PA this afternoon as some
cirrus moves over the ridge and a few stratocu develop in the
lower levels. Strong ridge over the Mid Atlantic with 594 heights
through Central PA will continue into Sunday. Skies should be
mainly clear tonight. Dew points in the northern mountains still
in the upper 50s to lower 60s so another comfortable night in the
north. Temps and dew points will converge around the mid 60s by
morning in the lower Susq Valley. Some low clouds or light fog may
.SHORT TERM /SUNDAY/...
A weak cold front will bring the chance for showers or
thunderstorms later Sunday afternoon/evening - mainly over
northern and western sections of the state. Weighted our previous
fcst POPs to the latest run of the Superblend. Little or no chc
for precip across the far SE zones remains.
SPC has placed the NW third of our CWA in a Marginal Risk for
severe Sunday afternoon and evening...which looks pretty good
based on moderate, westerly deep-layer shear and a SW-NE ribbon
of rather impressive MU cape of 2500-3500 j/kg extending from
near KELZ and KBFD...to KBTP.
Gusty (and highly localized damaging) westerly winds will
accompany the storms in the 18Z Sunday - 01Z Monday period in the
MRGL Risk area.
Above normal temps will continue on Sunday with similar maxes (or
perhaps just a few deg f lower than Sat`s across the Susq Valley).
Highs expected to range from the mid 80s (mtns) to near 90F in the
Lower Susq Valley.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The extended period looks like it will feature a transition from
a persistent upper-level ridge over the eastern United States to
an upper-level trough over the northeast by next Thursday and
Friday. As a result, above-normal temperatures early in the week
will transition to near...then likely a few to several deg below
normal by late next week.
The weakening cold front (noted in the Short Term period above)
will push slowly SE through the Commonwealth Sunday night into
Monday morning accompanied by isolated to scattered showers.
The frontal boundary is expected to wash out near or just south of
the Mason/Dixon line during the day Monday. Abundant low-level
moisture...mesoscale convergence and some orographic lift/heating
via the East to NE llvl flow regime across the mtns of SW PA will
focus the best chc for showers and scattered thunderstorms there
Monday night through Wed morning looks to be dry...with generally
light wind and just some patchy early morning fog throughout the
valleys of central and northern PA.
A second...and likely stronger cold front should push SE across
the area Wednesday afternoon or early Thursday, with a renewed
chance for showers and thunderstorms.
This front will be followed by a cool-down for the end of next
week. Max temps should be mainly in the 70s Thursday through
Saturday (over central and SE PA)...but may hold in the mid to
upper 60s acrs the NW mtns Thursday and Friday...as a deep upper
trough amplifies from central Quebec...to the Mid Atlantic
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Good VFR will continue through the remainder of the day.
Overnight, patchy fog will develop a few hours before sunrise.
However, using persistence, kept all sites VFR with only a minor
reduction in visibility.
Good VFR is expected Sunday. Scattered thunderstorm development
will be possible across the northwest quadrant of Pennsylvania Sunday
afternoon along/ahead of a cold front advancing eastward across
the Lower Great Lakes into the Upper OH Valley. A few storms may
produce strong to marginally severe sfc wind gusts.
Mon-Tue...Predominately VFR with isolated P.M. TSRA possible.
Wed...Scattered TSRA probable with cold front passage.