Area Forecast Discussion
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FXUS61 KPBZ 260528
Area Forecast Discussion
National Weather Service Pittsburgh PA
1228 AM EST Sun Feb 26 2017
High pressure will build in today. A weak crossing disturbance
is expected Monday before a warm front moves north across the
area Tuesday. A late Wednesday cold front will return wintry
weather for the last half of the week.
.NEAR TERM /THROUGH TODAY/...
Broad upper troughing, and some lake and terrain enhancement
should keep scattered to numerous snow showers N of PIT and in
the PA/WV/MD ridges overnight. Scattered flurries are expected
elsewhere. Snow should end by morning as high pressure builds in
and the flow backs SW. Expecting a clearing trend today also
under the building high. Temperatures are expected to be near
the seasonal average.
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
Surface high pressure will begin to shift eastward early in the
short term period. This will mean dry and relatively clear
conditions will quickly be replaced by increasing cloud cover on
Sunday night. With a fairly linear jet streak parked directly
overhead the CWA slowly beginning to migrate eastward into
Monday, a weak H5 vort looks to traverse the Ohio Valley on
Monday. Weak warm advection ahead of it may be just enough to
generate a shower or two through the day Tuesday. Some
soundings indicate that a brief window of snow may be possible
at the onset due to wide surface dewpoint depressions and low
wet bulb zero heights, however very light qpf expectations
combined with warm advection and no support for below freezing
temperatures should preclude any possibility of accumulation
should this occur.
With the northward migration of a warm front through the area
on Tuesday, temperatures during the short term look to return to
above normal yet again. Fries
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A brief dry interlude follows th weak system from Tuesday
before much higher PWATs follow for later Tuesday night into
Wednesday night. A couple of successive waves look to pass the
region in deep southwesterly flow. Some heavier rainfall may be
possible with these given PWAT values running up toward 1.3
inches and a nicely couple jet structure to accentuate ascent.
A trailing cold front will pass the area on Thursday. This will
set temperatures into a free fall with model and ensemble
consensus 850 mb temperatures falling into the negative teens
Celsius. This should bring lake and upslope snows back into the
picture. Additionally, some model indications exist of a weak
system dropping through the Ohio Valley on Friday in the colder
air. This could end up being a modest snow maker somewhere in
the region depending upon its track.
The extended forecast was generally favored colder than the
SuperBlend guidance from Thursday night through Saturday due to
the amplitude of the pattern and magnitude of cold air set to
advect into the region. Fries
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --Gusty west winds will slowly decrease over the course of the
night under continued low VFR cigs and intermittent light snow
showers until shortly after daybreak. Cloud coverage will
decrease today as high pressure builds in from the west.
Restrictions will be possible again Tuesday morning as the next
weather system impacts the region.
pattern is maintained for
the first half of the week.
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