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Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

                            
000
FXUS61 KCTP 250930
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
530 AM EDT Sun Aug 25 2019

.SYNOPSIS...
High pressure over over Northern New England will provide cool-
dry weather through Monday. And increasing southerly flow ahead
of an approaching cold front will bring some wet weather for mid
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
An almost carbon copy of last night with the valleys filling
with fog. An elongated upper low just off the Southern New 
England coastal waters is bringing some patchy mid clouds 
westward. 

The low is forecast to move east today, but will likely provide
for a mix of sun and clouds for the first half of the day until
it moves east of Cape Cod later today.

Highs today in the 70s will be slightly below normal. 

The recent string of cool dry nights will continue tonight with
valley fog once again developing late.

&&

.SHORT TERM /MONDAY/...
We will start to see clouds creep in as we develop a southerly 
flow with the high moving off the New England coast. We should
stay dry with highs very close to what we see today.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As the southerly flow increases between the high to the east 
and an approaching front to the west, so too will the chances
for rain. I brought in the first mention of some spotty light
rain Monday night, with more general scattered showers
developing on Tuesday.

Models are in decent accord in bringing a cold front into the 
CWA for mid week. The system is made to degenerate as it moves
east and encounters unfavorable low level shear associated with a
sprawling offshore low. Showers will still be widespread, but 
overall QPF should remain on the light-moderate side.

Dry weather will return for the end of the week. From there some
model timing differences arise with a cold front for the
weekend. The GFS/Canadian are in accord with this weak feature
sparking some new showers, while the ECMWF holds showers off
until Sunday. Given the low confidence, I used blended POPs for
the Sat-Sun timeframe.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
09Z TAFS sent.

More information below.

For the 06Z TAF package.

Less clouds across the north tonight than last night, and winds
not as strong as last night, thus some fog at times at BFD. BFD
still clear but reporting 3/4SM BR as of 1110 AM.

Otherwise, looking at clear skies overnight.

Earlier discussion below.

High pressure and associated dry air mass will build southeast
from the Great Lakes, ensuring VFR conditions and light winds
through Sunday over most of central PA. The only exception will
be in some of the river/stream valleys of central PA, where 
late night fog will form. NAMNest and LAMP guidance indicate fog
will develop around 07Z and dissipate by 13Z-14Z Sunday. KBFD, 
KIPT, KAOO and KUNV are the only airfields that stand a slight 
chance of vis reductions early Sunday morning. 

.Outlook...

Mon...AM low cigs/fog possible.
 
Tue...AM low cigs possible Allegheny Plateau. Potential for some
showers.

Wed...Showers and AM cig reductions possible.

Thu...No sig wx expected.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...La Corte
LONG TERM...La Corte
AVIATION...Fitzgerald/Martin