-- Discussion containing changed information from previous version are highlighted. --
051
FXUS61 KCTP 160512
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
112 AM EDT Sun Jun 16 2024

.SYNOPSIS...
* Canadian high pressure will build southeastward into
  Pennsylvania this weekend, providing sunshine, seasonable
  temperatures and low humidity on Sunday.
* An anomalous subtropical ridge will build over the East Coast
  next week, accompanied by an extended period of hot and humid
  weather.

&&

.NEAR TERM /THROUGH TODAY/...
High pressure will continue to to build to the northwest of
Pennsylvania with cloud cover breaking up across central and
western Pennsylvania this evening. Cirrus associated with a weak
shortwave will continue to drift towards the western periphery
of the area early this evening. Cloud cover, while expected to
be thin, will be one of two main deterrents for any fog
formation across northern PA overnight into Sunday morning
coupled with dry air at the lower levels.

The thin nature of cirrus clouds will still allow for
radiational cooling across the region overnight and have
continued to cut back NBM MinTs, with low temperatures ranging
in the mid-40s to the mid-50s which will be near-to-slightly
below climatology for the middle of June.

The surface high will move east of Pennsylvania on Sunday, but
continue to allow for mostly to partly sunny conditions and
slightly warmer temperatures with southerly flow. The bulk of
central PA will lower 80s outside the highest elevations of
Schuylkill County and the northern mountain zones with MinTs
dipping into the 60-65F range, but could trend lower with some
potential for radiational cooling depending on northward
positioning of the ridge.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
A subtropical ridge will begin to build along the East Coast
with the passage of a surface warm front on Monday allowing for
increased heat and humidity during the early stages of the work
week. Cannot rule out a SChc of a shower/storm over the the
higher terrain of the Allegheny Plateau on Monday where the best
forcing and moisture will be available. Otherwise, it will be a
very warm and increasingly humid afternoon.

Heat and humidity takes hold over all of central PA on Tuesday,
with an outside chance of a shower/storm across the northern
tier during the afternoon and evening hours. MaxTs ranging from
the lower-to-upper 90s, coupled with dewpoints in the upper 60s
to the lower 70s will allow for heat index values to push
close to and slightly above the 100F mark across the Lower
Susquehanna Valley with upper 90s elsewhere outside of the
Laurel Highlands.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
All medium range guidance is in agreement that a prolonged heat
wave will occur throughout the extended forecast period. A
595-600 dm 500 mb ridge will be situated over Central
Pennsylvania and temperatures will easily reach the 90s across
most of the region each day. Heat indices will be in the upper
90s and low 100s, with the Wednesday-Friday timeframe looking
like the hottest period. Some models indicate the potential for
a few showers or thunderstorms each afternoon across the
northern tier, but coverage should be very limited.

Ensembles show the ridge beginning to flatten out a little by
Saturday which would allow for a slightly higher chance of
showers or storms, particularly across the northern half of the
area.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
High pressure over the area will keep clear skies and light
winds over our area into Monday morning. The airmass is quite
dry, so the chance of fog is very low, especially with the
short nights.

The earlier shift added VCFG to KBFD and KIPT as overnight low
temperatures near dewpoints that occurred on Saturday.

Outlook...

Mon-Thu...Predominantly VFR, with building heat. Density
altitude concerns possible.
-- End Changed Discussion --

&&

.CLIMATE...
A period of much warmer than average temperatures is expected
across much of central Pennsylvania next week, with record high
temperatures being challenged. The record high temperatures for
some sites across central PA are outlined below:

 Jun 18 Jun 19 Jun 20 Jun 21

Harrisburg      97/1957     98/1994     98/1931     98/1923
Williamsport    97/2018     96/1929     101/1923    97/1933
State College   94/1923     94/1931     94/1953     94/1988

&&

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

&&

$$

SYNOPSIS...NPB
NEAR TERM...NPB
SHORT TERM...Evanego/NPB
LONG TERM...Bauco
AVIATION...Martin
CLIMATE...NPB