706
FXUS61 KCTP 160230
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1030 PM EDT Mon Jul 15 2024

.SYNOPSIS...
The heat will continue as unseasonably warm air is directed into
the state on SW winds. More storms with gusty winds and hail
will move through Tues afternoon and evening. A cold front will
push through on Wednesday with another round of strong to
severe thunderstorms. High pressure will build in from the Great
Lakes and control things for the rest of the week.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Convection linked to MCV over upstate NY has exited the
northeast part of the forecast area late this evening. Surface
high pressure building into the area should result in fair
weather overnight, with patchy late night valley fog forming
where rain fell over the northern part of the state. Can`t rule
out a shower/tsra toward dawn over the northwest corner of the
forecast area associated with next shortwave rotating through
the Grt Lks.

Min temps are expected to range from the mid 60s over the N
Mtns, to the low and mid 70s across the southern half of the
state, where pwats are highest.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Large Bermuda High and associated southwest flow will yield another
hot and humid day across the region Tuesday. Max temps could
potentially be even a bit higher than today, based on progged
ensemble mean 850mb temps. However, an approaching shortwave
should produce afternoon convection over at least the northern
part of the state, which could temper the heat by afternoon.

Diurnal heating, combined with surging pwats ahead of the
approaching shortwave, should yield developing tsra during the
afternoon with the highest POPs across the central and northern
part of the state per latest guidance. The strongest mid level
flow and deep layer shear is progged over the northern part of
the state and the best combination of late day instability/shear
is targeted over the northeast part of the forecast area, where
HREF UHEL values are highest, signifying the best potential
storm organization. Line segments producing severe/damaging
gusts will be the main risk into early evening.

Convection should wane with loss of heating Tuesday night, but
the region will remain in a ribbon of anomalous pwats/instability
and prone to at least a slight chance of lingering showers/tsra
overnight.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
An upper level trough approaching from the Grt Lks will push a
cold front through the region Wednesday, accompanied by a round
of showers/tsra Wed afternoon into Wed evening. Cloud cover and
an early arrival of the fropa should keep the threat of severe
weather low over the northwest part of the forecast area.
However, pre-frontal heating of the a very moist/unstable
airmass, combined with a belt of relatively strong mid level
flow, support a possible threat of severe weather Wed PM across
the eastern counties. Cloud cover and convection should hold
temps down a bit Wednesday, even across the Lower Susq Valley.
However, surging dewpoints ahead of the front could still yield
heat indices near 100F across the southeast counties.

All medium range guidance supports a return to fair and
seasonable weather with much lower humidity late in the week, as
high pressure builds southeast from the Grt Lks. Will maintain
just a slight chance of convection along the southern tier
Thursday to account for some uncertainty regarding how far the
dying cold front makes it south of the Mason Dixon Line.

The stalled front is likely to return northward next weekend,
resulting in the return of diurnal convection, mainly over the
southern counties.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
SH/TSRA are popping up right on time with the heat of the day
and arrival of significant forcing/higher winds aloft. The
storms should pass thru BFD in the next couple of hours. More-
random storms are also popping elsewhere, and will threaten
MDT/LNS in the next few hrs, too. Much of the convection will
die off after we lose heating and the best upper level forcing
wanes/moves east of the area -- which should happen right
around the same time this evening. Some stronger gusts will come
out of those storms, but timing and probability of occurrence
at any of the terminals is so difficult to pinpoint. We have
added some expectations of timing of these storms using tempo
groups.

IFR cloud cover is likely for BFD tonight as the flow just aloft
is SWrly and stronger than last night, and there could be a few
patches of DZ. If rain does occur at UNV/IPT, there will be
some fog as the sky should partially clear out. LLWS not strong
enough to mention anywhere, with llvl flow above the decoupled
boundary layer <30kts in most places. JST may be the only
candidate for a WS mention.

Expect more of the same for Tuesday, with good forcing arriving
in the mid-day right at peak heating. Gusty winds are possible
with those storms. A potent cold front crosses the area in the
midweek and ushers in a cooler and drier airmass for late week.

Outlook...

Wed...Scattered SHRA/TSRA, with some brief IFR poss, mainly SE
and mainly in the aftn/eve.

Thu...AM SHRA poss SE, otherwise VFR.

Fri-Sat...No sig wx.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Tuesday for PAZ019-025>028-034-
035-045-046-049>053-058.
Excessive Heat Warning until 8 PM EDT Tuesday for PAZ036-056-
057-059-063>066.
Heat Advisory from 8 PM Tuesday to 8 PM EDT Wednesday for
PAZ036-056-057-059-063>066.

&&

$$

SYNOPSIS...Lambert/Dangelo
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Dangelo
LONG TERM...Fitzgerald/Gartner
AVIATION...Dangelo