268
FXUS61 KCTP 011817
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
217 PM EDT Sat Jun 1 2024

.SYNOPSIS...
*Splendid start to June with plenty of sunshine and low humidity
*Becoming cloudy on Sunday with some showers into Sunday night
*Trending warmer and more humid Mon-Tue; rain most likely Wed-Thu

&&

.NEAR TERM /THROUGH TONIGHT/...
A very pleasant and comfortable start to the weekend/first day
of June and meteorological Summer with plenty of sunshine,
seasonably warm temperatures, and low humidity. After another
relatively cool start, expect another large diurnal swing with
max temps rebounding +30 to +40 degrees from AM lows into the
75-85F range (0 to +5F above June 1 climo). Not as cool tonight
with increasing clouds and min temps in the 50s.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
Latest HREF indicates a weak sfc low moving into eastern Ohio
late Sunday with an ill-defined warm front extending into
southern PA.

This will result in lowering/thickening cloud bases and a
several to 8 hour period Sunday afternoon into Sunday night when
showers will become fairly numerous acrs primarily Western and
Southern PA with lower POPS of 40-50 percent across Northern PA.

Cloud cover and an associated lack of instability in the models
indicates thunderstorms are unlikely.

EFS max temps for Sunday are mainly in the 70s. However, later
shifts may have to dial back the temps IF the onset time of the
rain is sooner.

Passage of the shortwave should result in drier weather Monday.
However, the combination of a lingering frontal boundary south
of PA and high pressure to the north could result in persistent low
clouds, especially over Southern PA. Medium range guidance
points to fair and warm weather Tuesday, with ridging at the
surface and aloft over PA.

Previous...

Latest 2m temp ensemble plumes are widely diverging, with most
members cooler than the current forecast. Ensemble mean qpf
suggests most likely rainfall Sunday PM of <0.20 inches.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
A deepening upper-level trough stationed over the Great Lakes
will promote an unsettled pattern on Wednesday and into
Thursday. There remains some uncertainty with regards to timing
of precipitation as EC guidance outlines an extended period of
showers on Wednesday with a secondary maximum Thursday
afternoon while GEFS guidance indicates more afternoon/evening
rainfall both days. A slightly later shift in guidance favors
the latter option, but have still decided to keep likely
mentions out of the Wednesday/Thursday timeframe outside of
where a small overlap Wednesday night does warrant some likely
mentions across the western highlands.

Latest deterministic model guidance does outline slightly drier
conditions on Friday as the best forcing and moisture shifts
east of PA. Some chances remain for scattered diurnally-driven
showers, especially across the western zones with westerly winds
and a deep closed low stationed across the Great Lakes.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR conditions will prevail through 18Z Sunday with high (> 90%)
confidence. A high-level (10-15kft) SCT-to-BKN deck is expected
to traverse across the area during the overnight period with
some lighter winds and dry air limiting any fog potential
overnight into Sunday morning. After 15Z Sunday, some lower
level clouds (~5000ft AGL) will move into the western terminals
(BFD/JST) ahead of scattered rain showers with some potential
for lower visibilities. Have kept mentions of SHRA out of
AOO/UNV eastwards as low-level dry air shows some potential to
stall out precipitation until after 18Z Sunday.

Outlook...

Mon...Patchy AM fog, slight chance of PM t-storms.

Tue-Thu...SHRA and TSRA with restrictions possible.

&&

.CLIMATE...
Prelim May and Spring 2024 Temperature & Precipitation Rankings

Harrisburg: T12th warmest; 76th driest May
 T3rd warmest; 33rd wettest Spring

Williamsport: 9th warmest; 22nd wettest May
4th warmest; 11th wettest Spring

Altoona: 9th warmest; 13th wettest May
2nd warmest; 3rd wettest Spring

Bradford: 4th warmest; 36th driest May
Warmest; 21st wettest Spring

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert
LONG TERM...Fitzgerald/NPB
AVIATION...NPB
CLIMATE...Steinbugl