112
FXUS61 KCTP 160319
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1119 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 THURSDAY 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.

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.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Deterministic guidance converges towards a return towards fair
and seasonable weather with lower humidity Friday as high
pressure builds from the Great Lakes. The bulk of guidance keeps
dry conditions through Saturday morning so have capped PoPs
below SChc (< 15%) through this timeframe.

A stalled front is expected to nudge northward into the weekend,
allowing for a return to diurnally driven convection. Have
capped PoPs mainly to a SChc north of the turnpike Saturday
afternoon/evening with the northward extent of SChc creeping
into portions of the Middle Susquehanna Valley Sunday evening
where the front could continue to drift slightly north.

Model guidance does outline mainly dry conditions for the
majority of the day on Monday; however, diurnally driven
convection cannot be ruled out in the afternoon/evening hours
with the best chances mainly south of I-80. Have capped PoPs at
low-end Chc (20-30%) given some uncertainty wrt boundary
placement and how this will impact any potential convection.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
IFR cloud cover is likely to develop for BFD tonight as the
flow just aloft is SWrly and stronger than last night. Expect to
see some fog at IPT after 08z as well after earlier rain. Other
locales may see light fog/haze toward sunrise that will quickly
dissipate.

Showers may be impinging on BFD by mid morning Tuesday, but
otherwise VFR conditions expected into the afternoon as a breezy
WSW flow kicks in. Another round of showers/tstms in store for
afternoon/evening with good forcing arriving in the mid-day
right at peak heating. Pop up convection poss at MDT/LNS
starting around 18z. With a more organized broken line of
convection potentially reaching BFD around 18z, JST/AOO/UNV
20-22z, and IPT/MDT/LNS 23-01z which cound contain strong gusty
winds.

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/NPB
AVIATION...Dangelo/RXR