202
FXUS61 KCTP 111934
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
334 PM EDT Sat May 11 2024

.SYNOPSIS...
Upper level troughing will remain over Pennsylvania this
weekend with a potent shortwave tracking over the state tonight
into early Sunday. The upper trough will lift out early next
week, then a cold front will likely push through Tuesday. A wave
of low pressure is likely to track south of Pennsylvania next
Wednesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Upstream trough digging southeastward from the central GLAKS is
bringing a return to showers this afternoon as the upper low
tracks to southern Ontario by 00z Sun. Strong large scale
forcing, in combination with some minimal model cape, supports
high POPs with a tsra possible in spots, although areas east of
the Alleghenies will largely be stably stratified. Some activity
west of the mountains this evening will have the highest
likelihood of producing an isolated lightning strike. Showers
should reach peak intensity over the Central Mountains between
20-21z, and then push into the Susq Valley this evening.
Although a brief, heavy downpour will occur in many locations,
modest PWAT values indicate that rainfall should generally not
be very heavy. Ensemble mean qpf of 0.2 to 0.4 inches represents
the most likely rainfall by late this evening.

Upper trough continues to dig southeastward, cutting off along
the PA/NY border later tonight into Sunday morning. Aurora
watchers *MAY* be able to see somecolor tonight between the
cloud breaks, but we believe those will be few and far between.
Steep lapse rates under the upper low center will support plenty
of cloud cover tonight and Sunday and at least scattered
showers lasting into Sunday afternoon. Highs for Mothers Day
will range mostly through the 60s with upper 50s in the higher
terrain of the Alleghenies.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
The upper low lifts out Sunday night and Monday with improving
conditions for Monday, and temperatures moderating thanks to a
milder southwest flow. A cold front trailing low pressure in
eastern Canada is fcst to stall out over the lower Great Lakes
Monday and will trigger some showers or a t-storm over the NW
mtns Monday afternoon, but it appears most of Central PA should
start the week rain-free.

A wave of low pressure will approach from the Ohio Valley
Tuesday before crossing the area Tuesday night. This system
will be accompanied by a renewed chance of rain and perhaps
some thunder.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Lingering unsettled weather is possible into Wednesday, before
a ridge builds in Wednesday night into Thursday. This will
support the longest period of dry and sunny weather we have seen
in awhile. The overall upper level pattern heading into next
weekend looks rather blocky - which is typical for this time of
year - but also results in much lower confidence/predictability.
Such a pattern supports changeable weather with temperatures
oscillating around average for this time of year. Some data
suggest a cut- off low pressure system could bring a slight risk
of heavy rainfall on 5/18 per the latest CPC 8-14 day hazards
outlook.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR conditions will prevail until another round of rain showers
arrives from the west this afternoon evening. The main batch of
showers will last for a couple hours at each airfield with
limited thunderstorm activity. After the initial batch of
showers moves through, scattered showers and a few thunderstorms
will move across the region and will generally weaken with
eastward extent. Have not mentioned thunder in any TAFs at this
time, but may need to amend as observations warrant.

Ceilings will lower to MVFR across much of the area tonight as
winds shift to come out of the southwest and then west. IFR
reductions are most likely at IPT (70%) and MDT/BFD (50%) after
midnight. Scattered showers will continue overnight with
occasional visibility reductions possible. Clouds may scatter
out across the south central mountains, which would allow for
the potential of valley fog development. AOO is the most likely
airfield to be affect by fog at this point, but not enough
confidence to include mention in the TAFs.

As westerly winds develop on Sunday and occasionally gust to
20 kts, overcast skies will overspread the region with
widespread MVFR conditions continuing through midday. Gradual
improvement is likely during the afternoon, but scattered
showers will remain possible until daytime heating tapers off
later in the evening.

Outlook...

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

Mon...Morning fog across the east/Susquehanna Valley. Showers
return across the north by aftn.

Tue...Showers/tstms and reductions developing.

Wed...Showery weather and reductions continue.

Thu...Trending drier with more breaks in the cloud cover.

&&

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

&&

$$

SYNOPSIS...DeVoir/Fitzgerald
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Banghoff
AVIATION...Banghoff