Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

FXUS61 KCTP 250935

Area Forecast Discussion
National Weather Service State College PA
535 AM EDT Mon Mar 25 2019

Low pressure over southern Indiana will track south of
Pennsylvania late today. Canadian high pressure and associated 
dry air mass will settle south across the area during midweek. A
cold front is then likely to push southeast across the region 
next weekend.


Radar loop at 09Z shows diminishing pre-frontal showers 
across central/southern Pa, as parent shortwave and best forcing
shifts east of the state. By dawn, expect the dying cold front 
to have settled south to near the Mason Dixon Line and the 
showers to have dissipated due to the arrival of large scale 
subsidence behind shortwave.

The remnants of Miss Valley upper low and associated surface 
low are progged to track south of Pa later today. The latest 00Z
operational models and HREFV2 are supporting increasing 
confidence in the southern tier of the state being impacted by a
period of light rain, beginning around midday and lasting until
early evening. An examination of model soundings indicates 
some wet snow is likely on the ridge tops of southern Pa, 
mainly at elevations above 2000ft. Surface temperatures appear 
to be the limiting factor for any accumulations, but wouldn't 
be completely surprised if an inch or so was reported on the 
highest ridgetops south of the turnpike. 

After a cloudy start, surface ridging and much drier air mass 
building in from upstate NY should result in mostly sunny skies
across northern Pa today, while model RH profiles indicate overcast
conditions all day in the south.


Clearing skies will advance south tonight, as low pressure 
passes off the coast and high pressure builds south from NY 

Canadian high pressure will build into the region Tuesday,
accompanied by abundant sunshine and a light northerly breeze.
Mixing down model 850mb temps yields expected max temps ranging
from the upper 30s over the northern mountains, to the mid 40s
across the Susq Valley. 


Med range guidance continues to support a high confidence of
fair weather through midweek, as Canadian high pressure drifts 
southeast over the area. Nearly ideal conditions for radiational
cooling Tuesday night with high directly over the area, so have
leaned toward the colder ECM and MAV MOS over the NBM min temp

Med range guidance all indicating a dying cold front will either
approach or push into northwest Pa late Thursday into Friday,
accompanied by a chance of showers. Both the 00Z ECENS and
operational EC/GFS suggest the front lifts north of the region
late Friday and Saturday, as wave of low pressure forms over 
the Miss Valley and tracks northeast through the eastern Grt 
Lks. All guidance continues to suggest the best chance of 
showers comes next weekend, when east coast ridge breaks down 
and cold front pushes across the state. 

Above normal temperatures appear very likely Thu-Sat in the 
deep southwest flow between east coast ridge and approaching 
front. A transition to drier and colder conditions appears 
likely Sunday, as the front pushes east of the state. 


VFR conditions continue to prevail across the region tonight. A
cold front over central New York will slip southward through 
Pennsylvania during the overnight hours. A shift to northerly 
winds will accompany the frontal passage. While actual 
precipitation will be spotty overnight, increasing low level 
moisture and the upslope flow into the mountains will likely 
generate some MVFR ceilings.

On Monday, a weak wave will ride eastward along the front, which
should be south of Pennsylvania. Models generate limited
moisture with this feature as is is sheared, but threat exists
for some light precipitation and ceiling restrictions across the
southern tier during the day.

High pressure will then prevail through Thursday, with a frontal
system approaching for Friday.


Mon...AM rain/snow. Restrictions possible, mainly northern and
western mountains.

Tue-Thu...No sig wx expected.

Fri.....VFR, but with some scattered showers possible northwest.




NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald
LONG TERM...Fitzgerald