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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 061129
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
729 AM EDT Tue Jun 6 2023

.SYNOPSIS...
Dry and breezy conditions will be favorable for wildfire-spread
from late this morning through the evening. Smoke from wildfires
in Quebec, Canada will result in hazy skies and poor/unhealthy
air quality today. Temperatures will trend slightly cooler into
late week with an increased risk of scattered rain showers
Thursday and Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Initial s/w over northeast PA will rotate east-southeast off
the NJ coast this morning. A second s/w dropping southward from
upstate NY along the west side of a deep upper low over Nova
Scotia will reach northern PA by this evening. Hires models
indicate isolated convection is possible in advance of the
second s/w this afternoon-evening mainly over east central PA.
This has fire weather implications with the very rare potential
for dry t-storms which could cause initial fire starts in the
driest fuel beds. Both NAM and RAP forecast soundings depict
inverted-v soundings extending up to an altitude between 850-700
mb, with PW values in the 0.50-0.80 range, which tends to be
quite favorable for dry thunderstorms.

We segmented the expanded fire weather watch to account for the
isolated dry t-storm risk and critical fire weather area which
now includes portions of Schuylkill, Lebanon, and Lancaster
Counties which have the worst drought conditions and largest
short-term and YTD rainfall deficits. See fire weather section
for more info on conditions and anticipated product flow for
later this morning.

Smoke from wildfires in Quebec, Canada will result in hazy skies
and poor/unhealthy air quality today. PADEP has issued an AQA
for the Lower Susquehanna Valley. We added both haze and smoke
to weather grids today with 5-6SM visibility restrictions and
air quality impacts.

Outside of potential fire weather/smoke impacts, not a bad day
overall with hazy sunshine and breezy conditions with maxT
generally in the 70-80F range or +/- 5F either side of early
June climo. Any isolated showers/t-storm should dissipate this
evening, giving way to another mainly clear and cool night (minT
40-50F or -5 to -10F below climo) thanks to abnormally dry/low
pWAT air filtering into CPA.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
Similar pattern setup on Wednesday with aforementioned upper
trough expanding over New England and the Mid Atlantic states.
Airmass remains quite dry for this time of year and expect any
diurnal convection to remain spotty to isolated at best. MaxTs
trend a few to several degrees cooler vs. Tuesday with daytime
highs AOB daily climo. Smoke and haze issued will also likely to
continue to reduce visibility and air quality.

Fire weather risk remains elevated given ongoing abnormally dry
to moderate drought, low RH and breezy conditions. SPC has
outlined an elevated risk on the Day 2 fire weather outlook.

Another mainly clear and cool night with lows in the 40-50F
range.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The various ensemble prediction systems remain consistent in
their depiction of the large-scale pattern heading into the
weekend and early next week. The pattern will consist of a low
amplitude upper trough axis across eastern Canada and the
northeastern CONUS, with an upper ridge axis holding firm over
the middle of the CONUS and central Canada. Resultant NW flow
aloft will keep any sustained heat well west of the Commonwealth,
with a progressive surface cold front likely to cross the
region Sunday or Monday. However, transition from current
blocking pattern is still not fully certain, and so what we can
say for sure is that Sunday into Monday may present the best
CHANCE of rain we`ll see for the next week, but it`s far from
certain at this early time.

As for the daily sensible weather, Saturday continues to look
mainly dry. Scattered showers and thunderstorms remain possible
on Sunday, tied to the aforementioned cold front. Shower
chances may linger into Monday, depending on the progression of
the frontal zone.

Friday`s highs in the 70s, will warm into the mid 70s-mid 80s
over the weekend, before edging downward into the 70s range
again on Monday.

&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Surface ridging over the area is likely to result in mostly VFR
conditions this morning. Smoke from wildfires over Quebec could
potentially drop vsbys into the MVFR range over parts of
central PA into mid morning. Otherwise the focuse today will be
on a cold front, which will sweep south across the region. The
airmass is likely to remain too dry to support any showers, but
an isolated shower or thundershower is possible, mainly east.
Northwest winds are likely to become gusty during the late
morning and afternoon hours. Bufkit soundings support gusts
between 20-25kts over most of the region. Vsby reductions from
Quebec wildfires will remain a possibility Tuesday, especially
during the afternoon over northern PA. Any vsby reductions
should be in the 4-8sm range.

Outlook...

Wed-Sat...No sig wx expected.
-- End Changed Discussion --

&&

.FIRE WEATHER...
Elevated risk to critical fire weather conditions expected late
this morning through the evening across portions of east-central
PA. As highlighted in the near term section, there is the very
rare potential for isolated dry thunderstorms in the desert of
Central PA :) Parched soils and dry fuels combined with breezy
conditions are signaling potential Red Flag conditions; however
will consult partners at PABOF/DCNR later this morning before
issuing Red Flag Warning. Similar risks will exist tomorrow with
little change in the pattern and any rainfall not expected to
impact fine fuel moisture.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from 11 AM EDT this morning through this
evening for PAZ006-012-018-019-025>028-034>037-041-042-045-046-
049>053-056>059-063>066.

&&

$$
SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Fitzgerald/Steinbugl
LONG TERM...Jurewicz/DeVoir
AVIATION...Fitzgerald/Colbert
FIRE WEATHER...Steinbugl