406
FXUS61 KCTP 150031
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
731 PM EST Thu Nov 14 2024

.SYNOPSIS...
Light rain will continue overnight, mainly west of the
Susquehanna River. Milder weather is anticipated for the
weekend, and drier and breezier conditions will lead to an
elevated wildfire spread risk on Saturday. A passing rain
shower will be possible on Monday; otherwise continued
seasonably mild and dry through early next week

&&

.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
The steadiest rain continues to be confined to areas west of
the Susquehanna River this evening, and this will likely
continue to be the case through the night. Rainfall will
gradually taper off from north to south into the early morning
as the best upper level forcing shifts towards the Maryland
border with the shortwave passing well to our south. Model
soundings suggest that patchy fog and low clouds are likely to
develop across the western and central Alleghenies overnight.
Extensive cloud cover and lingering low level moisture should
prevent temperatures from dropping too much from their current
values tonight, with lows expected to be in the 30s and low
40s.

&&

.SHORT TERM /7 AM FRIDAY MORNING THROUGH SUNDAY/...
Any lingering showers and fog will dissipate Friday morning, but
upslope flow will keep low clouds around across the western
mountains. Downsloping northwesterly flow will allow for some
breaks of sun east of the Allegheny Front during the afternoon.
Highs tomorrow will be 5 to 10 degrees warmer vs. Thursday with
maxes generally above the historical average for mid November in
the upper 40s to mid 50s range. Low cloud hang tough over the
western Alleghenies and Laurel Highlands Friday night.

High pressure building in from the Grt Lks should supply fair
weather Saturday. However, model soundings indicate low level
moisture trapped beneath a subsidence inversion could result in
stubborn low clouds the first half of the day where the
northwest flow ascends the Allegheny Plateau. Mixing down
progged 900mb temps of 4-6C yields expected highs ranging from
around 50F over the highest elevations of the N Mtns/Laurels, to
around 60F in the Susq Valley. It will be breezy with wind gusts
from the northwest in the 20-30 mph range.

Potential for elevated to critical fire wx conditions will
result in the issuance of a fire wx watch for the eastern
portion of the forecast area on Saturday - which matches up well
with PA DCNR/BOF categorical very high fire danger risk.

Frosty start to Sunday with lows in the 25-35F range. High
pressure dome migrates over central PA on Sunday providing a
mostly sunny and pleasant end to the weekend with light winds.
Highs in the mid 50s to low 60s remain above average for mid
November.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A subtle shortwave is still progged to pass north of us Sunday
night into Monday morning. A weak and moisture starved
cold front will slide across the state as a result, but given
how dry the airmass will be PoPs have been capped near 30% and
are only present across the NW where moisture will be sufficient
for light precipitation.

Surface high pressure will build in along with upper level
ridging providing fair and tranquil weather for Monday afternoon
before clouds begin building in again for Tuesday ahead of a
digging upper level trough. High temperatures for the middle of
next week will moderate and become 10-15 degrees above normal
given relatively warm 850mb temps aloft. Additionally a slight
chance of rain will persist for Tue and Wed given the
uncertainty of the surface lows position off to our west.

Wednesday and beyond could be the first signal for a pattern
change across the region to become more cold and seasonable.
Strong high pressure will build across the western United States
with a deep closed low over the high plains that will likely
progress north eastward into the end of next week. Current
guidance has a deep surface low spinning over the western Great
Lakes at the end of next week which could bring in our first
wave of continental polar air for the season.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Rain has spread across much of the area, but still has not made
more than a sprinkle to the east of IPT and MDT. LLWS will be
waning as the sfc low drops to the south of the area early
tonight.

Confidence remains high (80%) in IFR conditions tonight into
tomorrow for BFD, JST, AOO, UNV with low ceilings and RA
turning to a fairly constant DZ. The ridge tops will be hidden
in clouds. Even though much of the rain will over before
sunrise, some DZ will linger into the morning at BFD and JST.
The IFR cigs will hold all day at JST and BFD without mixing to
help bring down some dry air from aloft. There`s a 50% chc that
the cigs will rise above FL010 by noon at UNV and AOO. IPT, MDT
and LNS barely go down close to IFR cigs. Have kept them at
OVC012 for the lowest as guidance keeps some separation between
T and Td for the lowest 1kft in the east. Any improvement to VFR
will be in the east after noon. UNV and AOO have a 50% chc of
going VFR before the end of the day. Cross-lake flow then
reinforces the llvl mstr and could even take IPT back to MVFR
for Fri night and Sat.

The NW wind above the subsidence inversion increases again Fri
evening and lasts into mid-day Sat, and may warrant an
additional mention of LLWS for the latter part of the 06Z TAF
package. The signal is strongest over the srn, esp 2 sern
terminals, where a tight gradient develops between the
departing, then off-shore, low and the high moving in from the
west. Sat aftn sfc gusts into the m20s at MDT and LNS.

Outlook...

Sat...IFR cigs rising to MVFR cigs JST/BFD. MVFR cigs AOO/UNV.
VFR elsewhere.

Sun...IFR BFD/JST early. Improvement to VFR for all terminals
through the day.

Sun PM-Mon AM...CFROPA. MVFR cigs/vis in -SHRA, mainly N half.

Mon PM-Tues...NW flow. IFR/MVFR cigs NW, VFR SE.

&&

.FIRE WEATHER...
A fairly tight pressure gradient between the upstream high and
low pressure over the Canadian Maritimes should result in wind
gusts Sat afternoon in the 20-25mph range over the eastern part
of the forecast area per latest Bufkit soundings. The winds,
combined with RH values dipping to near 30pct and very dry fine
fuels, will likely result in an elevated risk of wildfire
spread.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday morning through Saturday
afternoon for PAZ051>053-057>059-066.

&&

$$

SYNOPSIS...Bauco
NEAR TERM...Bauco
SHORT TERM...Steinbugl/Bauco
LONG TERM...Bowen
AVIATION...Dangelo/Bowen
FIRE WEATHER...Fitzgerald/Steinbugl