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Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

FXUS61 KCTP 240143

Area Forecast Discussion
National Weather Service State College PA
943 PM EDT Tue Apr 23 2019

A cold front will clear the area overnight. Wednesday and at 
least the first part of Thursday will feature mainly dry 
conditions once again under the influence of another area of 
high pressure. Fast flow aloft will keep it unsettled into next 
week, with the next frontal system slated to affect the area 
late Thursday night into late Friday.


Cold front crossing the Alleghenies now with a decent push of
drier air behind it. Fairly impressive moisture surge pushed
dewpoints into the mid to upper 50s over most of the area this
afternoon and evening. Highly sheared environment supported some
longer lived reflectivity cores aloft and weak rotation, but not
enough cold pools generated to sustain bowing line segments or
wind damage. It appears that many of the potential hail
signatures were wet hailstones aloft and larger raindrops as
well. Lingering activity is being maintained south and east of
the front as it swings across the eastern half of the CWA
through 06z. Still some rumbles of thunder as it does so, and
some gusts to 30 mph and brief downpours will still occur
through that time. 

The front will press on through and begin to clear things out 
after 06Z. However, clouds will hang tough over the Alleghenies
and Laurels tonight. Min temps expected to reach the mid to 
upper 30s northwest...ranging through the 40s most everywhere
else but the far south and southeast where lower 50s will


Gusty WNW wind on Wed. But, it may likely become a little less 
noticeable through the day as high pressure builds in from the 
west and gradient slackens slightly. Early clouds in the NW 
should clear out very nicely to leave a mostly sunny day. Maxes 
in the m50s N, but nr 70F in the SE valleys. Could be a 1 on the
local, experimental JB Index, but the wind probably keeps it as
a 2.


High pressure will build in and lead to a chilly start to 
Thursday before temps rebound back to slightly above normal. 
Morning lows likely dip into the low-mid 30s in the valleys of 
the northern mountains.

Models then focus on a vigorous shortwave sliding through the 
Gr Lakes for Thursday night and Friday. The surface low is made
to track north of the region leading to another cold front
moving through the region during the day Friday. Guidance is
rather stingy with the forecast instability so for now at least,
I left out the mention of thunder, but plenty of showers will
abound Thu night into first half of Fri with a soaking rain
becoming more likely.

Sat will bring another shot of cooler air and breezy conditions.
Models again diverging more prominently starting Sunday as GFS
brings another fairly vigorous wave across northern stream while
EC much weaker with this system. This impacts surface features
as well, leading to large differences continuing into Monday
where the GFS has a 1032 mb surface high and the EC brings a
weak 1013mb wave into the GLakes. So, definitely a lower
confidence foreast leading to a general chance of showers each
day with moderating temps.


00z update... Scattered showers/thunderstorms early this evening
(through 02-04z) could produce brief restrictions. 

Later tonight, post-frontal low clouds will produce fuel
alternate restrictions at KJST and KBFD, with some brief IFR
possible at KBFD. Other terminals should have VFR/unrestricted

VFR is anticipated area-wide on Wednesday. 

Surface winds will veer into the W at all terminal sites by
03-05z, with W-NW winds continuing on Wednesday, occasionally
gusting into the 20-25 kt range. 


Thu...VFR early, then possible afternoon and evening showers and
thunderstorms, with the potential for restrictions. 

Fri...Additional restrictions possible in showers/thunderstorms. 

Sat...Mainly VFR.

Sun...Potential showers and restrictions.




SYNOPSIS...Dangelo/La Corte
NEAR TERM...Dangelo/DeVoir
SHORT TERM...Dangelo