021
FXUS61 KCTP 022144
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
544 PM EDT Mon Jun 2 2025

.SYNOPSIS...
* Dry weather expected through midweek with hazy sunshine from
  Canadian wildfires
* Turning increasingly warmer and more humid later this week as
  the pattern shifts into summer mode
* Showers and thunderstorms return to the forecast from Thursday
  into the first full weekend of June

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Crazy rise in temp at BFD where it rose almost 30 degrees in
just 3 hrs. Many other locations also popped up vry fast when
the June sun hit them. Smoke to the left and right of us this
morning. But the plume that was to the west of the CWA is
diving southeastward, and should be overhead/centered on us
this aftn. Have not adjusted temps for the aftn, but have
adjusted dewpoints down a little, especially in the north and
east where the dry air above this morning`s inversion should mix
down. There is still some chc for the dewpoints to rise this
aftn as all guidance has a rise of 5-10F for most locations.

Prev...
Mainly clear and unseasonably chilly start to what is likely
the coldest morning until the Fall season. Several mesonet obs
in McKean, Elk, and Warren County (along with a few additional
well-known cold spots) have printed min temps in the 29-32F
range.

Fog in the river and stream valleys across the northwest
Alleghenies will dissipate this morning as temperatures warmup
quickly under hazy sunshine; this has also ended the frost
threat and the advisory was allowed to expire.

High pressure will provide the first of 3 dry days across CPA
with highs from the mid 60s over the northern and western
mountains to the low 70s elsewhere. HRRR vertically integrated
smoke suggests hazy sunshine throughout the day which should
lead to a vivid and vibrant sunset later this evening.

Mainly clear to partly cloudy and not as cold tonight with min
temps rising +10-20F night/night into the 45-55F range or +/- 3
degrees of early June climo.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Ridging at the surface and aloft migrating over CPA should
ensure two more dry days to round out the short term period
through midweek. We added haze to the wx grid on Tuesday based
on a blend of the HRRR near-sfc smoke density/vertically
integrated smoke and coordination with neighboring WFOs.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
High pressure sliding off to our east will allow for much
warmer air to work its way into central PA for the middle of the
week. Ensemble 850 mb temps in the 15 to 17 deg C range will
support high temperatures in the mid to upper 80s, with a few
locations potentially seeing highs break 90 degrees Wednesday
afternoon. It is unclear how much smoke will be overhead on
Wednesday and how much it will impact temperatures.The heat and
humidity may be somewhat impactful (despite max heat index
values only in the upper 80s and low 90s) given the early season
ramp up following a very wet and relatively cool May; the lack
of heat acclimation will also be a key factor. The HeatRisk
forecast peaks in the moderate level which would support
possible impacts in some health systems and heat- sensitive
industries.

Upper level ridging gradually slides eastward as low pressure
west of the area moves closer to central Pennsylvania on
Thursday. Surging PWATs and lowering heights ahead of this area
of low pressure support showers and thunderstorms Thursday
morning across northwest PA. As low-pressure approaches and
better moisture spreads into the area Thursday afternoon,
widespread rain showers appear increasingly likely as an
associated cold front approaches from the west. The cold front
will be slow moving and will likely be weakening as it moves in.
While guidance suggests that CAPE will range from 500-1500
J/kg, deep layer shear of less than 30 knots should limit the
potential for severe weather.

Confidence in the forecast becomes lower after Friday, though
some ensemble members along with much of the deterministic
guidance show an area of low pressure developing along the
frontal boundary and bringing another round of showers and
thunderstorms to much of the region on Saturday. The front
finally pushes east of Pennsylvania on Sunday and upper level
ridging attempts to build in behind it, bringing a period of
drier weather with seasonable temperatures to end the weekend.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
Late afternoon update.

Winds a bit stronger than expected, minor adjustments made.

Earlier discussion below.

High pressure will provide the region with mainly clear skies,
dry weather, and VFR conditions into Tuesday and Wednesday.
A few high clouds are around to start the morning today, and we
could see scattered high clouds moving across central PA this
afternoon, otherwise it will be mostly clear.

A plume of Canadian wildfire smoke will be injected into the
upper atmosphere over the Pennsylvania airspace this evening and
into Tuesday. So far there has not been any surface level
impacts from the smoke, mainly just hazy skies. Additional
mixing on Tuesday could bring smoke lower into the atmosphere,
but surface impacts still remain unlikely.

Outlook...

Tue-Wed...VFR expected.

Thu...Potential brief restrictions in SHRA/TSRA NW.

Fri...Numerous SHRA/TSRA, esp NW. Brief reductions to MVFR and
IFR in the TSRA.

&&

.CLIMATE...
The low of 28 degrees at Bradford this Monday morning broke the
old record of 30 degrees set in 1966.

More information below.

May 2025 Precipitation Rankings

Site                           2025 | Wettest May on Record
-----------------------------------------------------------
 Harrisburg*         10.02" Wettest | 9.71" in 1989 (previous)
 Williamsport     7.18" 7th Wettest | 9.91" in 1919
 Altoona*             7.34" Wettest | 7.31" in 1960 (previous)
 State College  7.56" T-7th Wettest | 9.45" in 1894

(* denotes that May 2025 set a new record in precipitation in
their respective locations. The previous record remains listed
under the "Wettest May on Record" column.)

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Dangelo/Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Bauco/NPB
AVIATION...Martin/Bowen
CLIMATE...NPB