Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 281704

Area Forecast Discussion
National Weather Service State College PA
104 PM EDT Tue Mar 28 2017

An area of low pressure will move along the Mason-Dixon line
through tonight...bringing showers to central PA and isolated
thunderstorms to southeastern sections today. High pressure
will build down out of southern Canada and bring cooler and
drier weather for Wednesday and Thursday.

A new storm system will approach for the end of this week with
the potential for more inclement weather.


.NEAR TERM /UNTIL 8 PM THIS EVENING/... Still some areas of
light rain over eastern areas and drizzle with low clouds in
central areas. But the main energy has moved off to our east.
GOES-16 shows all the cold cloud tops to our east and cold
conveyor lifting into NY.

A lot of dry air in western PA and the upper level low to our
south. So most of the significant rain is over. Gradual
improvement later this afternoon and evening.

Best POPS now in the eastern areas.



The rain threat should mostly be off to our east by 8-10 PM.

Improving conditions as the strong anticyclone to our northwest
slides slowly over the area. Should be near seasonal day with
mostly sunny skies and little chance of QPF.


The dry air and high pressure are in all of the most recent
guidance, implying Wed ngt and Thursday will remain dry and

High pressure, dry air, and normal to slightly below normal 850
hPa and 925 hPa temperatures imply near normal daytime highs.
Most of the 26/00-06Z U.S. and int`l model guidance (and EFS)
indicates more of southern...shearing storm track for late in
the week...thanks to a stronger and more wwd position of a deep
nrn stream vortex across the Canadian Maritimes.

The trend of the big model discrepancy for late this week and
this weekend (between the GFS and EC over the past several days)
has trended toward the GFS and its ENS members with southern
stream energy and its moisture being prevented from amplifying
with an associated storm track to our west.

Rather, what we see is a shift of the primary southern stream
sfc low track to our south as the potent midweek southern stream
sfc/upper low (that will be trying to take the turn northeast
across the Mid Miss Valley twd the Great Lakes) encounters great
resistance from the notably stronger WNW upper jet core
defining the northern stream that will be situated from the
Upper Glakes to the Mid Atl Coast.

With this type of consensus storm track, pops will be somewhat
less for Friday and Saturday (compared to a heavily weighted
EC/ECENS solution) and limited to mainly the southern half of PA
where some rain (or even an elevation-dependent rain/wet snow
mix) with expansive cooler and drier air north of PA.


Considerable areas of MVFR and IFR this morning in rain, mist
and fog. There could be the rumble of thunder in southeastern
areas this morning and early afternoon.

Conditions improve later today after 18Z but slow improvement.
Overnight the trend continues with better weather Wednesday.


Wed...A.M. restrictions; becoming VFR.

Thu...VFR/No sig wx.

Thu Night-Fri...Sub-VFR restrictions/rain likely.

Sat...Gradually improving conditions.




LONG TERM...Lambert/Gartner
AVIATION...Grumm/Steinbugl is the U.S. government's official web portal to all federal, state and local government web resources and services.