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Area forecast discussion 
National Weather Service State College PA
311 am EDT sun Apr 26 2015

weakening low pressure will track south of Pennsylvania early this
morning...followed by a weak ridge of high pressure building south
across the state this afternoon. A persistent upper level trough
over the northeastern United States will favor unseasonably cool
temperatures through the end of the month.


Near term /until 8 am this morning/...
extensive middle cloud shield will continue to blanket the southern
tier counties of Penn early today...while thinner cirrostratus
extends across the area around Interstate 80.

Aside from a few sprinkles or flurries across Somerset
County...the rest of the forecast area will stay dry with a light NE

Min temperatures around sunrise will vary from the u20s across the the middle and upper 30s over the south.


Short term /8 am this morning through 6 PM Monday/...
narrow surface ridge and associated band of dry air/low precipitable waters will slide
south into central PA this morning. Thus...see a mainly sunny
start to the day. However...upper trough and associated cool temperatures aloft
will be swinging south into the state by expect plenty
of afternoon cumulus and even a few isolated -shra...especially over the north mountains

Given the expected sparsity of coverage and low precipitable waters ...any
measurable rainfall will be a very low probability. Thus...will
not explicitly mention -shra in forecast at this time.

Latest...00z gefs mean 800 mb temperatures support maximum temperatures from near 50f
across the northwest near 60f across the lower susq
valley...still well blw normal for late April.


Long term /Monday night through Saturday/...
active northern and southern stream split flow pattern across
North America will keep the region in upper level troffiness
through much of the period. The blocked up northern stream...generally
northwest flow pattern over the northeast will tend to shunt southern stream
system to the south of PA.

Early next week a shot of cool unsettled weather arrives as a back
door cold front is nudged southward across PA from an upper low
over new eng. Cool temperatures aloft associated with upper low will likely
lead to a good deal of daytime cloudiness and scattered rain showers /esp over
the mountains/ Monday and Tuesday.

By midweek...this low finally lifts out for good..but digging
trough from upper Midwest will extend into the southeast U.S. By
late week...combined with a southern stream shortwave lifting out
of the S plains toward the East Coast will bring possibility of a
developing storm sliding northeastward off the eastern Seaboard.
Track/strength still quite uncertain...but at this time looks like
we/ll be between that low pressure area and a high over Ohio
Valley...likely keeping clouds and scattered showers around as temperatures
cool back down a bit.


Aviation /06z Sunday through Thursday/...
weakening low pressure will track south of Pennsylvania early this
morning...followed by a weak ridge of high pressure building south
across the state this afternoon.

VFR conditions will prevail across central PA through the taf
period. Through 10z...a 3500-4500 deck will be possible across the
south under a blanket of middle clouds. As the low moves away...these
will sag to the south with clearing skies working in from the
north. Light winds will turn to the north and remain less than 8
miles per hour through 15z.

During the day Sunday...a scattered-broken 4000-5000ft deck will develop
across northern/western higher terrain as cooler air aloft begins
to arrive. Winds will also pick up across these areas to
10g18mph. The central and southeast will see few-scattered flat cumulus develop
with north/northwest winds of 8-10 miles per hour.

Ceilings will lower across the northern mountains and Laurel Highlands
Sunday night...with scattered light rain/snow showers developing in
these areas. Elsewhere...conditions should remain VFR before
restrictions become poss on Monday.


Monday...areas of MVFR with scattered/numerous rain or snow
showers...mainly across western/northern higher terrain.

Tuesday...areas of MVFR with scattered light rain showers. Improving to VFR
late. sig weather.

Thursday...MVFR poss in scattered rain showers.


Ctp watches/warnings/advisories...


near term...Fitzgerald/Lambert
short term...Fitzgerald/la corte
long term...Lambert/gartner

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