834
FXUS61 KCTP 161859
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
259 PM EDT Sun Jun 16 2024

.SYNOPSIS...
*Partly to mostly sunny and warmer for Father`s Day
*Long duration and potentially dangerous heat wave this week
*High temperatures 90+ degrees Monday into next weekend

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
1025AM/1424UTC: Minor tweaks to hourly T/Td/Sky grids based the
latest obs and visible satellite trends. Main focus for the rest
of the day will be on heat product flow (WWA) with impending
heat wave to set impact the area this week.

Previous Discussion Issued: 448 AM EDT Sun Jun 16 2024

Surface high pressure centered over upstate NY will pass off of
the New England coast later today, resulting in fair and
seasonable conditions across Central PA with a slightly warmer
return southerly flow. Upstream satellite imagery and model
guidance indicate warm advection aloft ahead of a shortwave
lifting over the Grt Lks will result in some mid and high level
cloudiness across Central PA today, mainly through early
afternoon. However, on balance mostly sunny wording should
suffice for the area. Mixing down model 850mb temps of around
14C yields expected highs ranging from the mid 70s over the
mountains north of KIPT, to the mid 80s in the Lower Susq
Valley.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/...
A building subtropical ridge over the East Coast will bring fair
and increasingly hot weather to Central PA early next week.
Warm mid level temps should largely suppress convection.
However, isolated convection is possible Monday afternoon,
primarily over the Laurel Highlands, where the elevated heat
source could aid in breaking the cap. Scattered, pulse-type
convection appears possible Tuesday afternoon, primarily along
the spine of the Alleghenies.

Mixing down 850mb temps yields highs in the upper 80s to low 90s
Monday and mostly low to mid 90s Tuesday. The increasing heat,
coupled with dewpoints in the 65-70F range, could result in
heat index values close to 100F in the lower elevations east of
the Allegheny Plateau by Tuesday afternoon.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
All medium range guidance continues to show 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. Temperatures will ramp up each day
giving us our hottest day by midweek. Heat indices will be in
the upper 90s and low 100s, with the Wednesday-Friday timeframe.
Corridanting with surrounding office on the timing and extent of
either Advisories or Watches. Some models indicate the
potential for a few showers or thunderstorms each afternoon
across the northern tier, but coverage should be very limited
and elevation driven.

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 /19Z SUNDAY THROUGH FRIDAY/...
Good VFR across the entire area through the forecast period. Any
localized wind gusts this afternoon will diminish toward sunset.
Dry air should keep any fog from forming overnight.


Outlook...

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

&&

.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...Steinbugl
NEAR TERM...Fitzgerald/Steinbugl
SHORT TERM...Fitzgerald
LONG TERM...Tyburski
AVIATION...Tyburski
CLIMATE...NPB