079
FXUS61 KCTP 072328
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
728 PM EDT Tue May 7 2024

.SYNOPSIS...
- A warm front will drift northeast across the area this
  evening with scattered showers and a possible thunderstorm
  across southern PA.
- Low pressure moves just north of the area tonight into
  Wednesday morning, brining showers and thunderstorms.
- A stronger wave of low pressure will move across southern PA
  Thursday evening.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A warm front will continue to track northeastward across central
PA this evening, with scattered showers expected mainly along
the spine of the Alleghenies and south of State College. SBCAPE
values generally remains in the 500-1000 J/KG range with
localized maxima across southern PA. Some elevated instability
so have kept in a SChc of thunderstorms across S PA
(Cambria/Blair southward) in showers this evening with highest
chances across the PA/MD border in the next couple of hours.

Temps did slightly overperform today, allowing for slightly
warmer than forecast MinTs this evening with increasing cloud
cover throughout the evening and overnight hours. MinTs will
remain fairly uniform ranging from the upper 50s across the
northern tier to lower 60s across the southern tier.

Low pressure moves toward PA and western NY late this evening
and will cross the area overnight. PWAT values topping out near
1.5" with an increase in CAPE will promote numerous SHRA/TSRA.
It is of note that recent runs of hi-res guidance does indicate
a slightly later arrival time with precipitation entering
central PA after midnight. Models continue to outline that the
area of greatest coverage remains across W PA in the 03-07Z
timeframe overnight as the nose of a moderately strong, 35-45 KT
LLJ approaches the region.

Intense/near-severe storms overnight shouldn`t get much farther
east than a BFD-UNV-AOO line. SPC has the SWrn corner of the
CWA into the MRGL risk for svr wx as a cold front moves through
the area. The period of showers and a few TSRA will peak
between about midnight and 5 AM across Central and Eastern parts
of the CWA.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Model guidance tracks the weak surface low north of PA
Wednesday, with a weak trailing cold front coming through during
the morning hours. Any morning showers should give way to
increasing sunshine, as drier air works in behind the front.
Model 850mb temps near 15C support highs ranging from the mid-
and upper 70s over the N Mtns, to the low and mid-80s in the
valleys of Central/Southern PA. Mixed in lower PWATs via the NBM
25 pctl values for Wed afternoon as sfc dewpoints dive into the
40s (and possibly a few u30s across the Northern Mtns) during
the late afternoon hours.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
While Wednesday will be mainly dry for much of the time, wet
conditions work back into the area for Thursday. A sfc low
still looks like it will track right along the PA, MD border.
High temperatures for the most part will be below 70 degrees,
and extensive cloud cover as well, will limit the chance for
thunder. SPC has slight near the border in the far southeast.
Storm development will depend on the track of the low and
if much in the way of heating can occur during the day on
Thursday.

While rain will not occur all the time on Thursday or be very
heavy, much of the day will feature at least some spotty rain
and drizzle.

While the low moves off the coast on Friday, cooling aloft will
result in a chilly day, along with some showers.

A brief break is likely for early Saturday, but another low
drops southeast later on during the weekend, so looking at no
real dry spells anytime soon. An upper level ridge building
across the western states will aid in keeping more of the same
type of conditions over our area into early next week.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A shower could produce a brief vis reduction in the vicinity of
KMDT/KLNS through around 01Z. Otherwise, confidence is high for
widespread VFR flying conditions and light winds across Central
PA this evening.

Low pressure lifting through the Eastern Grt Lks will spread a
broken line of showers/tsra through the region late tonight,
lasting 2-3 hours and accompanied by possible MVFR vis
reductions. An increasingly moist southwest flow ahead of an
upstream cold front is then likely to yield late night IFR cigs
at KBFD and possible IFR cigs at KJST. Downsloping flow east of
the Alleghenies should result in nothing worse than MVFR
conditions over that part of the state.

The passage of a low level jet late tonight could result in
borderline LLWS conditions across the W Mtns late tonight.
However, the 18Z Bufkit soundings suggest we will remain just
below criteria.

The cold front will sweep through the region later Wed morning,
probably without any precipitation. A drier westerly flow behind
the front will bring a return to widespread VFR conditions
between 12Z-15Z.

Outlook...

Thu...Periods of rain/low cigs possible, mainly PM.

Fri...Low cigs/drizzle possible, especially in the morning.

Sat...PM showers/low cigs possible, mainly W Mtns.

Sun...AM low cigs possible W Mtns. Sct afternoon showers/brief
vis reductions possible.


&&

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

&&

$$

SYNOPSIS...NPB
NEAR TERM...Lambert/NPB
SHORT TERM...Lambert/NPB
LONG TERM...Martin
AVIATION...Fitzgerald