608
FXUS61 KCTP 151902
AFDCTP

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

.SYNOPSIS...
The heat will continue as unseasonably warm air is directed into
the state on SW winds. A compact but potent upper level
disturbance and strong winds aloft will bring a round of strong
to severe thunderstorms that will be focused across Central PA
and the Mid Susquehanna Valley later this afternoon and evening.
Additional storms with gusty winds and hail will move through
in the afternoon and evening Tuesday. A cold front will push
through late 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 11 PM THIS EVENING/...
SVR watch in effect until 7 PM for the nrn half of the CWA as
0-6km shear climb into the 35-40kt range and MLCAPEs go as high
as 1500-2000J. CI already happened over the NW on the leading
edge of the best forcing of an MCV from overnight convection. A
second shortwave trough - looking for all the world like a
hurricane - over OH has also started to pop deep convection in
wrn PA. A couple of TSRA should pop up in other seemingly
random locations, too as broad lift is underway in advance of
the general upper trough to our west. The convection is
expected to be through IPT/UNV well before dark, and continue
SEwrd. However, the loss of the best heating should diminish the
punch of the storms. We may end up expanding the watch a bit
more to the S and E or hook up with a subsequent watch for ern
PA a little later this aftn if things develop on schedule. Main
threat today is damaging wind, but some hail is possible, mainly
in the NW. All heat flags looking solid with only minor/small
changes to temps/dews in the very near term.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Left over convection should dwindle early tonight. The SW flow
just above the blyr will bring thick mstr/low clouds into the
Alleghenies overnight. This should keep temps up. The clouds may
be thick enough to make a little DZ, too. To the SE of the
Allegheny Front, the clouds will be more sct and higher-based
with not much in the way of low clouds to the SE of Blue
Mountain. Still, even without thicker cloud cover, mins won`t
drop past 70F in most places, and maybe not <75F in the cities
of the Lower Susq. Thus, the heat advy and warning have been
allowed to continue. We`ve even added a heat advy for Wed to the
going suite of products as temps/dews remain high, but not quite
as high as Mon/Tues thanks to extra cthat we`ll keep away from mentions in the TAFs at this
point. We may add details as confidence increases in timing as
the storms near.louds and anticipated cfropa. Tues still looks
like the hottest/highest-heat-index day. A round of at organized
severe convection is expected Tuesday PM ahead of cold front
pressing slowly southeast through the Great Lakes and into PA
later Tues night.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
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 /19Z MONDAY 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...Dangelo
SHORT TERM...Dangelo
LONG TERM...Fitzgerald/Gartner
AVIATION...Dangelo