982
FXUS61 KCTP 131646
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1246 PM EDT Mon May 13 2024

.SYNOPSIS...
A warm front will brush northern PA today before a cold front
pushes through 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 /UNTIL 6 PM THIS EVENING/...
Warm front lifting across northern PA this morning maintaining a
band of showers that will remain along and north of I-80. Some
stratus associated with the warm front is crossing the central
mountains and have adjusted sky grids to reflect this for the
next few hours...with mostly sunny conditions returning for the
afternoon.

Upper level ridging building over PA will result in warmer and
drier conds overall. The aforementioned warm front may still
lead to some afternoon shra/tsra across the northern half of
central PA, but coverage will be sparse this afternoon. Partly
to mostly sunny skies and a developing southwest flow should
push readings well into the 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
High pressure passing off of the east coast and the resulting
southerly breeze should result in a significantly milder Monday
night, with lows in the 50s. Generally fair weather should hold
tonight with upper level ridging over the state. However, a
weakening shortwave lifting out of the Ohio Valley could support
a late night shower over primarily the southwest part of the
forecast area.

Expect an increasing chance of showers and possible 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.

All guidance tracks the surface low linked to the approaching
shortwave south of PA Tuesday night into Wednesday, resulting in
another period of rain. Latest 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. The S may have isold diurnal convection - but
shortwave ridging will likely 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 /THURSDAY NIGHT THROUGH MONDAY/...
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 /18Z MONDAY THROUGH SATURDAY/...
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