Altoona, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

512
FXUS61 KCTP 230958
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
458 AM EST Sat Nov 23 2024

.SYNOPSIS...
* Gusty northwest winds today with showers over the western
  Alleghenies, followed by improving conditions on Sunday.
* Cold front brings rain Monday night into Tuesday followed by
  another period of gusty winds midweek.
* Another round of winter weather is possible for Thanksgiving
  Day and Black Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
With the upper level low now off the coast, we`re left with
northwesterly flow and improving conditions across the region
this morning. Breaks in the clouds are evident for most of the
eastern two thirds of the Commonwealth on nighttime microphysics
imagery. Weak low level cold advection overnight has resulted
in morning temperatures in the low to mid 30s areawide.

The northwest flow behind the departing upper low is just cold
enough to support lake effect showers today. Model soundings
show inversion heights peaking late morning through the
afternoon hours, coincident with the passage of a weak upper
level shortwave. Have ramped POPs upward toward the HREF values
due to nearly saturated model soundings in the 0-2km layer,
which should support light precip in most spots across the
Allegheny Plateau. A few wet snowflakes are possible on the
higher ridgetops of the Laurel Highlands this morning, but
thermal profiles are too warm for anything but rain showers
elsewhere.

A fairly tight gradient west of intense low pressure over Nova
Scotia will result in gusty northwest winds across the area
today. Bufkit soundings indicate frequent gusts of 20-25kts are
likely. GEFS 2m temp anomalies support near seasonable high
temps as well, ranging from the low 40s over the highest
elevations of the Alleghenies, to the low 50s in the Lower Susq
Valley. Mostly sunny skies east of the Allegheny front this
morning will gradually give way to increasing cloudiness through
a combination of lake enhanced cloud streets and warm advection
ahead of an approaching shortwave.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
A weak shortwave diving across the Eastern Great Lake should
sustain scattered lake effect rain showers over the Allegheny
Plateau into early Sunday. Lows tonight will be a bit milder
than this morning, in the 30s to lower 40s with more clouds than
sun overnight. Ridging building into PA on Sunday should
support fair and milder conditions through Monday AM. Winds will
also taper off noticeably on Sunday afternoon and evening.

By Monday morning, a warm front will be across northern PA with
warm advection ongoing across PA with southerly winds. Monday
will be the warmest day of the week as temperatures trend +5 to
+10F compared to normal. Increasing clouds Monday afternoon
will precede the arrival of a few showers along a cold front.
CFROPA in the late night/early morning time-frame will probably
keep the chc for thunder low, but would not be surprised to hear
a rumble or two since the front is potent and 8H temps drop 15C
over 12 hrs at UNV. Could be a gusty passage, too (potential
NCFRB) due to 8H winds from 240deg at >=50kt per GFS. WPC QPF
paints the highest rainfall totals in northwest PA (upwards of
half an inch) with generally less than a tenth of an inch across
the Lower Susquehanna Valley through Monday morning.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
* Winter Weather may impact travel on Thanksgiving Day across
  Central PA

Tuesday looks mainly dry with high pressure building in. A
tightening surface pressure gradient will support gusty
westerly winds, perhaps approaching 30-40kts. A snow showers is
also possible in northwest PA.

Wed now looks fairly good for travel across PA with ridging
building over the state. A bit of lingering lake effect snow
is possible over the NW Mtns early in the day. Much of the
medium range model guidance tracks an area of low pressure
northeast from the Lower Miss Valley late next week, spreading
precipitation across PA for Thanksgiving Day. A track south of
the Mason Dixon Line suggests there will be enough cold air
present for snow over at least Northern PA. However, there
remains plenty of uncertainty this far out and a significant
number of ensemble members are weaker and further south with the
area of low pressure. Will continue to monitor the forecast as
confidence is expected to increase over the next 2 to 3 days.

Current timing and placement of mass features should allow for
gusty winds and drying on Friday except in the northern
Alleghenies where the cold air and WNW flow will generate
lake effect SHSN which may linger thru much of next weekend
(days 7-9). A shot of even colder air comes along late in the
weekend, and looks like a pattern favorable for snow squalls.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
The main area of rain and snow continues to push southwest this
evening and steady rain and snow is mainly confined to areas
near and southwest of JST and AOO. Ceilings have risen over the
past few hours to MVFR for areas east of the Allegheny Front and
further improvement to VFR is possible towards daybreak
(especially at MDT and LNS). Moderate to heavy snow continues at
JST as of 00Z and is leading LIFR restrictions. This will
continue for a few more hours before drier air moves in
overnight and brings an end to steady snowfall. While
visibilities will improve, ceilings will remain IFR. Gusty winds
20-30kt from 280-320 degrees will continue through Saturday.
Showers will develop once again Saturday afternoon near BFD and
JST and could reach as far east as AOO and UNV.

Outlook...

Sun...MVFR cigs NW 1/2 impacting KBFD and KJST. VFR elsewhere.

Mon-Tue...Strong CFROPA Monday night with rain and potential
LLWS followed by strong winds and snow showers.

Wed...Not as windy with MVFR to VFR cigs; mixed precip could
reach the southwest airspace by 12Z Thu.

&&

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

&&

$$

SYNOPSIS...Steinbugl/Banghoff
NEAR TERM...Fitzgerald/Banghoff
SHORT TERM...Fitzgerald/Banghoff
LONG TERM...Fitzgerald/Dangelo
AVIATION...Steinbugl/Bauco