550
FXUS61 KCTP 131710
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
110 PM EDT Mon May 13 2024

.SYNOPSIS...
A warm front will lift north of the Commonwealth by tonight,
with mainly fair weather expected into Wednesday. A cold front
may touch of a few afternoon showers on Tuesday. A wave of low
pressure tracking south of the Commonwealth will continue
showery conditions on Wednesday with drier conditions expected
Thursday and Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Warm front is making the jump northward early this afternoon,
with stratus and light showers lifting north of the PA/NY border
and Endless Mountain region and a good deal of sunshine north of
I-80. Areas south of I-80 have been mostly sunny since morning
fog burned off, and will continue that way through this evening.
An examination of latest guidance indicates quite a bit of mixed
layer CIN in the wake of this morning`s warm frontal showers
over N Central PA. MLCAPEs do recover sufficiently for perhaps
an isolated shower or storm, especially along and north of Rt 6,
but coverage appears less than earlier anticipated and have
shaved POPs for the remainder of the daylight hours after the
current showers over Sullivan County exit shortly.

For the overnight, shortwave ridging along and sfc high
pressure moving off of the east coast and a resulting southerly
breeze will result in much milder conds than last night. Lows
will range through the 50s. A weakening shortwave lifting out
of the Ohio Valley could support a late night shower over
primarily the southwest part of the forecast area.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
After a much needed but too short reprieve, we`ll see increasing
chances for showers and possible afternoon tsra Tuesday associated
with an approaching southern stream shortwave lifting northeast
from the Southern Miss Valley. Model RH profiles support mainly
overcast skies, which should act to limit heating and the
chance of tsra. However, surging low level moisture, combined
with modest diurnal heating, should support fairly widespread
showers and isolated tsra by late afternoon based on the 00Z
HREF.

Guidance continues to track surface low linked to the
approaching shortwave south of PA Tuesday night into Wednesday,
resulting in another period of rain. Ensemble plumes suggest
around a half inch of rain is likely in most spots by Wednesday
evening. Have tweaked temps downward slightly from NBM guidance
Wednesday due to the expected rain and easterly flow. Raw
NAM/GFS surface temps peak in the 60s over most of the region
Wed. Expect rain to end Wed evening, as the low exits the Mid
Atlantic coast.

Thursday still has the possibility of being dry for most
locations. Some guidance is depicting somewhat of a ring of fire
feature across western and northern areas with isold diurnal
shra or tsra possible, but for most areas the shortwave ridging
should keep it dry. Left the 20-30 PoPs in for Thurs given by
the National Blend respecting the low predictability of timing
and strength of mesoscale features, like the aforementioned
small ridge aloft, at this range.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
Lingering unsettled weather is likely late this week into early
next week.

Northern stream trough and veering return flow will reintroduce
shower chances Thursday night and Friday. Lightning chances
certainly in the cards given our placement in a warm sector
airmass with a surface low in southeast Canada.

The weekend`s sensible weather remains far from certain as a
southern stream upper low meanders to our southwest and
potentially phases into the aforementioned northern stream
trough. Positive phasing would likely result in an unsettled and
potentially wet weekend yet again, while clearer skies would
prevail if this low becomes cutoff from the northern stream and
brings shortwave ridging. Heights aloft however look to remain
fairly steady at this point, keeping temperatures on the
seasonably warm side with highs in the 70s and lows in the 50s.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
A few of the sites in the eastern airfields this morning are
experiencing low clouds from a southerly stream of moisture.
Elsewhere morning valley fog is beginning to lift. Winds should
remain light this morning before ridging continues to build in.

After fog lifts/mixes out, VFR conditions prevail for everyone
today. Winds could become somewhat gusty as high pressure
riding builds and becomes dominant; however, a few light
showers are possible for northern airfields later in the
afternoon (BFD, UNV, and IPT) from a weak upper level trough,
but no restrictions are expected at this time. Most places will
remain dry throughout the day. The next chance for rain and
visibility restrictions will be during the early morning hours
on Tuesday as the next disturbance makes its way to PA.

Outlook...

Tue...Showers/tstms and reductions developing.

Wed...Showery weather and reductions continue.

Thu...Slow improvement, with a few lingering showers possible.

Fri...Deteriorating conditions with showers increasing.

&&

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

&&

$$

SYNOPSIS...Dangelo
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Guseman/Dangelo
AVIATION...Bowen