713
FXUS61 KCTP 161349
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
949 AM EDT Thu May 16 2024

.SYNOPSIS...
* Rain-free for most and seasonably warmer into Friday with
  areas of fog overnight
* Another wet, cloudy, and cool start to the weekend with
  only marginal improvement on Sunday
* Trending warmer and drying out Monday & Tuesday before
  showers and t-storms return next Wednesday

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
GOES Geocolor satellite and FAA/RWIS obs trends indicate fog is
lifting with visibility improving >3SM. Allowed DFA to expire.
Latest hires model signal was strong enough to add mention of a
stray to spotty shower possible this afternoon/evening mainly
across the western and northern Alleghenies. Overall, still a
dry day in most of CPA.

Previous Discussion Issued: 536 AM EDT Thu May 16 2024

A weak ridge of high pressure at the surface and aloft will
drift east from the Ohio Valley and bring clearing skies and
comfortable dewpoints/RH with a light to moderate north to
northeast breeze and moderate gusts into the teens across the
eastern part of PA late this morning through the afternoon.

Temps to start this Thursday will be mainly in the 50-55 range.

Areas of low clouds and fog are likely to persist through
this morning across primarily the Northern and Western Mtns
of the state, while the patchy dense valley fog dissipates and
sunshine mixed with fair weather dominates through the
afternoon.

Ridging, particularly aloft to the west of a stacked low
offshore the Mid Atlantic coast, combined with lower PW air
directed into the region via northerly low level flow favors
decreasing/lower POPs and a welcomed dry day for most locations.

Latest hires model data and EFSs suggest that a stray
diurnal/instability or terrain induced rain shower or t-storm
cannot be ruled out, especially along and west of the Allegheny
Plateau tomorrow afternoon near quasi-stationary front/low
level convergence zone. Still, will only carry around 10 percent
pops and leave the mention of precip out today, so we don`t
spoil the enjoyment of at least one dry day.

High temps today will be mainly in the 70-75F range across most
of CPA.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY NIGHT/...
*A cloudy/wet pattern resumes Friday through much of Saturday

The mean low level flow turns back to the east/southeast
Tonight into Friday. This should result in low clouds, patchy
fog and a relatively mild night tonight into Friday morning
before a cloudy and slightly cooler end to the week.

Large scale forcing downstream of mid/upper trough moving into
the Ohio Valley combined with building instability banked along
and west of the Alleghenies favors highest POPs across the
western and southwestern portions of the CWA Fri- Friday night.
Consensus of guidance brings showers and storms to western PA
early Friday afternoon and the rest of the Commonwealth during
the afternoon and evening. Lows continue to trend above mid- May
climo in the 55-60F range Friday night into AM Saturday. QPF
totals through Friday night (ending 12Z Saturday) range from
~0.10" in the southeast to ~0.50" across parts of the western
mtns.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
*Cloudy & wet start to the weekend; marginal improvement Sunday
*Drying trend with more sun and warmer temperatures Mon-Tue

Low pressure tracking to the south of PA combined with plenty of
easterly flow will translate into another cloudy and wet
Saturday with highs in the 60s. The cold air damming pattern
presents high confidence in temperatures ending up lower than
guidance, and highs in the upper 50s to low 60s may be a more
reasonable expectation for what feels like an unending stretch
of miserable Saturdays in Central PA.

The departing low will slowly exit stage right as high pressure
builds into the area. This will mean low clouds likely stick
around early Sunday, but conditions should gradually
improve/dry out by Sunday night into Monday. Highest uncertainty
in the forecast at this time is if Sunday stays
cloudy/cool/rainy or if a bit of sunshine can peek through and
help temperatures rebound to seasonable levels. Regardless of
the details, POPs will trend lower through the weekend and highs
will recover by at least 5 to 10F on Sunday compared to Monday.

Decent model and ensemble signal for dry wx and more sunshine
leading to seasonal warming trend next Monday-Wednesday as a
potential cutoff low parks over the Carolinas and high pressure
builds overhead. Max temps are forecast to climb back into the
75-85F range. We have the greatest confidence for 2 consecutive
dry days (Mon & Tue) with the next frontal system projected to
arrive around midweek.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
As the sun came up this AM, patchy dense fog and LIFR low cigs
were found across the central mtns and portion of the western
highlands. The Lower Susq Valley (MDT, LNS) remains VFR, with a
light northwesterly breeze.

Model guidance indicates that the fog/low clouds should mix out
in the 13Z-15Z timeframe. Confidence in VFR conditions is high
across Central PA for Thursday afternoon. A northerly to
northeasterly breeze of 5-10 kts will develop areawide, with
gusts of 15+ kts possible across the Lower Susq Valley.

Conds will start out the night VFR, but a light easterly flow
could lead to the formation of low clouds across portions of the
area once again tonight. The highest probability of IFR conds
(50-70% chc) will be across the central mtns and the western
highlands.

Outlook...

Fri...AM low clouds/fog possible. Otherwise, becoming VFR. PM
showers/storms and reductions possible west.

Sat...Rain/low cigs likely, esp in the morning. Low cigs could
linger over the Laurel Highlands into the evening.

Sun...AM low cigs possible.

Mon...Patchy AM valley fog possible. Otherwise, becoming VFR.

&&

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

&&

$$

SYNOPSIS...Steinbugl/Banghoff
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert
LONG TERM...Steinbugl/Banghoff
AVIATION...Evanego