Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 250912

Area Forecast Discussion
National Weather Service State College PA
512 AM EDT Wed Apr 25 2018

Low pressure moving through the Mid-Atlantic will produce
scattered showers today. High pressure will move in tonight and
dry things out for Thursday. The weather will remain unsettled
as the pattern stays active into the first half of the weekend.

A stretch of fair, dry weather will start Sunday. Temperatures
will warm nicely next week as high pressure floats across from
Canada, but then sets up as a Bermuda High and turns the wind
out of the south.


Elongated low pressure now over NC/VA will creep northeast and
eventually through NJ later today. Multiple, weak waves aloft
will make it unsettled today, but the major wave will not arrive
from upstream until tonight. Coverage of showers will never be
100pct over the area, so it is tough to justify cranking up the
POPs all the way. Still, lots of showers, all pretty light, will
hang around all day. Temps won`t move up more than 5-6F over
the west today, and perhaps only 10 degrees in the east. But,
everybody will get into the 50s and some into the lower 60s. Not
too much below normal.


Sharp trough over nrn ONT and the Upper Great Lakes will cut off
and move across NY tonight and early Thurs. The effect will be
to reinvigorate the showers just as they start to die. The
upslope into the Alleghenies and Laurels will keep a few showers
around into the night, but they should dwindle by sunrise or
very shortly afterward. Behind this stronger upper trough, we
will have a short visit by high pressure on Thursday.


All the models agree that a weak and fast-moving sfc low will
zip through the Mid-Atlantic on Friday. The eventual rain shield
and northwestward extent of it is in question. Have tempered the
POPs a little as the EC and NAM both are drier this cycle. The
highest POPs will be over the SE, and least along the northern

An upper trough just moving into the PAC NW will arrive sometime
early in the weekend, perhaps not too far behind the weak system
for Friday. This will keep it unsettled into Sat. Big
anticyclone strengthens as it drops down from the great white
north. It will benefit from a giant upper ridge which will
amplify as next week begins. The high moves to a very favorable
spot for PA - centered along or just off the NC coast. The warm
return flow will lead to a nice change from the dreariness of
the next few days.

But before the warm, there will be a frost/freeze risk Monday
morning. This is also thanks to the big sfc high being centered
overhead at that time. Temperatures will then trend notably
warmer with readings in the 70s/approaching 80F in some
locations by next Tuesday as the Bermuda high exerts a positive
influence on the region. An extended period of dry and a green
up which is only just beginning over much of Central PA could
spell fire wx troubles next week.


Still showers to the east, less to the west. Could be a rumble
of thunder across the southeast, left out of the LNS and MDT
TAFS for now.

06Z TAFS sent.

Earlier discussion below.

Latest Radar showers widespread light showers moving northward
and overspreading the region. Currently, JST has dropped to IFR
with MVFR at BFD, MDT, LNS and AOO. However all sites are expected
to continue to deteriorate between 03Z to 06Z with widespread
IFR across all TAF sites between 06Z to 13Z.

Conditions improve starting over the southern mountains and Susq
Valley on Wed as flow turns to the west and downslope begins to
dry out the lower layers. But an upper trough slides in
reinforcing clouds over the NW half and brings scattered
showers. So MVFR is still expected through Wednesday afternoon.


Thu...AM low cigs possible W Mtns.

Fri...Areas of rain with low cigs etc.

Sat...AM showers/cig reductions possible NW Mtns.

Sun...Reductions possible NW Mtns.




NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...Dangelo/Steinbugl
AVIATION...Ceru/Martin is the U.S. government's official web portal to all federal, state and local government web resources and services.