845
FXUS61 KCTP 041616
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1216 PM EDT Tue Jun 4 2024

.SYNOPSIS...
*Warmest day of the week Tuesday with a stray shower possible
*Cloudy and humid with showers and a thunderstorm Wed-Thu
*Cooler/more comfortable stretch Fri-Sun with passing showers

&&

.NEAR TERM /THROUGH TONIGHT/...
Patchy fog in the valleys early this morning; otherwise mostly
sunny and very warm today (warmest day of the week) with highs
in the 80-90F range or +5-15 degrees above early June climo.

580dm ridge over CPA should help to maintain dry wx in most
locations this afternoon and evening. However, strong diurnal
heating may be enough to break through a weak capping inversion
and trigger isolated PM convection. Latest HREF suggests the
best chance of a stray pulse type shower/t-storm will be along
the southern tier ridges into WV/MD panhandle where pwats ramp
to 1-1.3 in.

An increasingly moist (higher pwats & dewpoints) southeast flow
ahead of an upstream warm front over the Ohio Valley will send
POPs on a upward trend from late tonight into Wednesday morning.
Expect a muggy overnight with fairly uniform min temps in the
60-65F range (+10-15F above climo) with low stratus and patchy
fog developing over the majority of CPA/east of the Allegheny
Front by daybreak.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Latest suite of medium range guidance expands coverage of
showers Wednesday morning through Wednesday afternoon with max
POPs occurring Wednesday night into early Thursday morning. The
best instability/chance for t-storms is over the southwestern
zones where a conditional late day severe wx threat is possible.
PWs climb to 1.25-2.00 inches by 00Z Thu which favors potential
for locally heavy rainfall amounts -- WPC has maintained a MRGL
ERO over the entire forecast area for the day 2 period.

Model consensus shows QPF max shifting to the east Thursday
morning as the frontal system moves across PA. The remainder of
Thursday should feature scattered showers/PM t-storm as upper
low and cooler temps aloft begin to impinge on the area. Most of
this activity will be diurnally driven with little to no precip
expected Thursday night.

Persistent low clouds and southeast wind favor cooler max temps
Wednesday (5-10 deg lower than today) with highs in the 70-80F
range. Post frontal westerly/downslope flow along with breaks
of sun in the dry slot should push temps back up on Thursday
with highs peaking in the mid 80s in the Lower Susq Valley.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
The main weather feature for Central PA through next weekend
will be a slow-moving upper low, tracking from the eastern
Great Lakes across southern Ontario and Quebec. As a result, at
least hit and miss showers and possible thunderstorms are
expected on a daily basis, with diurnally more numerous coverage
anticipated in the afternoon and early evening hours,
particularly for the northern tier of the Commonwealth.

Current indications are that by the end of the weekend into
early next week, the upper tough becomes positively tilted and
the low may retrograde slightly and stall over the great lakes
region. This will continue the unsettled pattern of diurnally
driven showers and thunderstorms through at least Monday
afternoon. Long range ensembles currently show the trough
lifting after Tuesday morning with fewer showers expected as a
result.

Temperatures are likely to average somewhat below climatology
for early to mid-June, with daily highs in the upper 60s and
70s, and overnight lows in the 50s to lower 60s.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
Looking at a mainly dry remainder of the day with high pressure
in place overhead. A slight chance of a shower or storm, mainly
over the south is possible for the late afternoon. These showers
will be isolated to scattered in nature and confidence is low
for any impacts to airfields. All sites are expected to remain
VFR through the remainder of the day and into the overnight
hours.

There is a slight chance of some fog and lower clouds to develop
into Wednesday morning given higher dewpoints ahead of an
approach cold front with southeast flow. Fog development could
be hindered by high clouds building in during the afternoon, but
it is worth mentioning the possibility.

More in the way of showers and storms will be possible late
Wednesday into Thursday, as a cold front moves across the
region.

Outlook...

Wed-Thu...More numerous showers and thunderstorms, with at
least brief restrictions.

Fri-Sat...Hit and miss afternoon showers and thunderstorms with
brief restrictions, otherwise mostly VFR.

&&

.CLIMATE...
Prelim May and Spring 2024 Temperature & Precipitation Rankings

Harrisburg: T12th warmest; 76th driest May
 T3rd warmest; 33rd wettest Spring

Williamsport: 9th warmest; 22nd wettest May
4th warmest; 11th wettest Spring

Altoona: 9th warmest; 13th wettest May
2nd warmest; 3rd wettest Spring

Bradford: 4th warmest; 36th driest May
Warmest; 21st wettest Spring

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Air Quality Alert until 11 PM EDT this evening for PAZ057-059-
063-065-066.

&&

$$

SYNOPSIS...Steinbugl/Banghoff
NEAR TERM...Fitzgerald/Steinbugl
SHORT TERM...Fitzgerald/Steinbugl/Banghoff
LONG TERM...Fitzgerald/Bowen
AVIATION...Bowen
CLIMATE...Steinbugl