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Area forecast discussion 
National Weather Service State College PA
1118 PM EDT Tue Oct 25 2016

changeable weather - some of it winter-like - is in store for the
region. One weather system arriving late Wednesday night which
will bring rain to most of the area and some mixed precipitation
to the north. After the cold front GOES by, the cold northwest
flow returns for a day or two. Another system is slated to affect
the area over the weekend, but should be milder than this first
one. Temperatures should average near to slightly below normal
with some moderation likely into early November.


Near term /until 6 am Wednesday morning/...
skies remain mostly clear across central and southern portions...
but seeing a renewal of lake stratus increasing across the north
thanks to persistent llvl cold advection and favorable boundary
layer trajectories into north central and northeast PA.

Clouds will continue to hang the toughest in these areas
overnight...while mostly clear skies prevail elsewhere along with
light winds. This will provide good radiational cooling
throughout...and likely end the growing season for the remainder
of south central PA.


Short term /6 am Wednesday morning through Wednesday night/...
wx grids have many more colors on them Wed night than they have
for many months.

Most of Wed will be a decent day with a mostly sunny start. High
clouds will move in from the west in the afternoon. The high/mid
clouds will be getting fairly thick across most of the area by
sunset, but there is only a minuscule chance of a shower/sprinkle
in the far west before 10pm. The thickening clouds and light southeast wind
will help keep temps near normal - that is - above freezing in the
south and valleys, and around or slightly below freezing in the
north. After midnight, a cold rain is forecast to slide quickly
W-E across the northern tier as the low approaches and upper
trough digs a little over the upper Great Lakes. Rain will likely
make it into the central third of the state, and probably into The
Laurels. But, the sern part of the County Warning Area could stay dry for much of
the night.

Now, for the ?Fun? - Precip type issues arise across the northern
tier where temps at the sfc and in the lower 6kft get sub-freezing
at different times during the night and early thurs morning. Right
now, the soundings and sref probabilistic p-type data all point
to a mix of rain and sleet falling at first as the precip begins
in the northwest - but it then turns to rain in Warren and much of McKean
co. The nern counties will have the sleet/snow-favorable profile
for much of the night and into the daylight hours Thursday. This
looks very much elevation-dependent, as most October events are.
The ground temps are still rather warm, but time of day/night is
favorable for accums to occur (no solar heating). Will paint in
all the precip types but freezing rain for now in the NE for 6-9
hours. Quantitative precipitation forecast could reach more than a half of an inch in the north -
and frozen precip (read: snow and sleet) accumulations will push 2
inches on the highest ground. Much of the area will pick up an
inch or so of the mixed frozen stuff. Might be an interesting
transition and mix of flakes, Needles, sleet pellets, etc. As the
event unfolds since the model soundings show wild mixing of
different intrusions of warm and some cooling at varied times.
Again, most of the southern two-thirds of the area will have no
chance for frozen precip.


Long term /Thursday through Tuesday/...
low pressure center will move across the Lake Erie area Thursday
with warm advection across central PA. Mixed precipitation in the
morning in the northeast will change over to rain. The southern
areas will break into the warm sector earlier in the day with
precipitation becoming scattered showers. Associated cold front
will sweep across PA Thursday evening with colder northwest flow
and maybe some lake-effect showers overnight mixing again with
some snow in the higher elevations across the central northern
tier. Flow changes during the day as winds begin to veer already
in advance of the next system approaching the Great Lakes. So
brief high pres ridge across central PA Friday.

This next system looks to track a bit further north giving US a
warming trend. Northern tier may see some precip as the warm front
pushes northeast. Southern areas will be mild and relatively dry.
Another dry period will likely follow the weekend system with
signs of a warming trend into the first week of November.


Aviation /02z Wednesday through Sunday/...

Skies are scattering out as drier upstream air begins to work into
the region. The exception is over the north closer to the
moisture streaming off the lakes.

Much of the area will be clear to scattered with widespread VFR
conditions expected. Some patchy late night fog is possible -
mainly along/in the river valleys, but the airmass is dry so
confidence is low.

Wednesday will be VFR ahead of a storm system that will be moving
into the lower Great Lakes by late in the day. A warm front will
lift north into the area Wednesday night and Thursday bringing
widespread reduced conditions.

Outlook... shrasn/low cigs possible west mtns.

Sat...rain showers W/IFR cigs possible north PM. Otherwise no sig wx.

Sun...rain showers W/MVFR cigs north and west. Breezy northwest wind.


Ctp watches/warnings/advisories...
freeze warning from 2 am to 9 am EDT Wednesday for paz026>028-


near term...dangelo/devoir
short term...dangelo
long term...Watson corte

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