Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 020430
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1130 PM EST Mon Mar 1 2021

.SYNOPSIS...
Occasional snow showers will taper off tonight as arctic air
surges in from the northwest. Blustery northwest winds will
send temperatures into the low teens and 20s with single digit
wind chills. The rest of the first week of March looks mainly
dry with moderating temperatures through midweek followed by a
cooling trend into the weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Scattered light snow showers continue along NW to SE oriented
horizontal convective rolls in the Laurels and northwest
mountains of Pennsylvania. Overnight, expect snow showers to
gradually taper off with forcing for ascent exiting to the
northeast along with a deep upper trough.

In its wake, steep low-level lapse rates will continue to mix
down strong gradient winds aloft, resulting in sensible wind
gusts in the 35-45mph range overnight. Occasional peak wind
gusts in the 40-50mph range have been observed at Altoona,
Lancaster, Capital City (CXY), and MUI, with numerous reports of
greater than 35mph. Expect gusty winds to continue through the
pre-dawn hours and then gradually taper off Tuesday morning.

As snow showers taper off and gusty northwest winds continue,
a sharply colder airmass will continue to pour into the
Commonwealth with temperatures already into the upper teens at
Bradford as of 10PM. Lows will bottom out in the low teens
across the northern tier and low 20s in the south central
mountains. Blustery conditions and resulting wind chills in the
single digits to below zero Tuesday morning may end up being the
coldest air until the fall - time will tell.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
After a very cold start, expect a fair and seasonably cold day
on Tuesday with max temps 5 to 10F degrees below daily climo.
Plenty of sunshine and subsiding winds will be provided
courtesy of high pressure building into the area from the Ohio
Valley. Clear skies will also provide for a clean picture of
Pennsylvania from our weather satellites, which are sure to
display a stark decrease in snowcover since the last clear day
on Thursday February 25th.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
By Wednesday, a southern stream wave of low pressure will stay
well south of the Commonwealth, with dry conditions persisting.
Southwesterly flow will help push temperatures into the low 50s
across the south central mountains. By Wednesday afternoon, a
trough will sag south into Pennsylvania, producing an increase
in cloudiness in the northern tier and Laurels.

Latest ECENS and GEFS guidance support a deepening trough over
the northeast through the weekend, with a trend toward
increasingly below-average temperatures, breezy conditions,
and continually dry conditions for Pennsylvania. Westerly to
northwesterly flow will continue to reinforce the 5F to 10F
below normal airmass. With very little moisture to tap into, any
precipitation will be confined to lake-effect snow showers in
the northwest mountains. Since Lake Erie is almost fully iced
over in the preferred source region, sufficiently cold 850mb
temps are more difficult to find. As such, have kept PoPs quite
low and focused on best potential on Thursday morning and Sunday
morning as shortwaves move overhead.

By Sunday afternoon, we begin to see some subtle differences in
the long range guidance related to the eastward propagation
speed of the upper trough. The operational ECMWF is a bit
slower with the system, resulting in a delayed arrival of
moderating temperatures & more cloudiness. The GFS on the other
hand, builds in a ridge more quickly with warmer temperatures
building in to start the second full week in March. Regardless,
it appears increasingly likely that temperatures will moderate
considerably into the middle of March.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Blustery west-northwest /290-310 degrees/ wind gusts 25-35kts
will impact CPA airspace through tonight. Moisture streaming
off of the Grt Lks is likely to produce occasional MVFR cigs
over northwest Pa (KBFD) later tonight and possibly over the
Laurel Highlands. Elsewhere, downsloping flow should yield VFR
conditions over the rest of the area tonight.

Expect diminishing winds Tuesday, as high pressure builds into
the state. There could be some lingering MVFR cigs across
northwest Pa (KBFD) during the morning. Otherwise, model
soundings and SREF/HREF prob charts support a high confidence
of VFR conditions.

Outlook...

Wed...Low cigs possible at night W Mtns.

Thu...AM low cigs possible W Mtns.

Fri-Sat...No sig wx expected.

&&

.HYDROLOGY...
Falling stages areawide and the trend should continue through
the week. Hogestown (HGSP1), Harper Tavern (HTVP1), and
Confluence (CNFP1) are above caution stage, but will fall below
critical thresholds by Wednesday morning. Dry weather and
gradual warming should help mitigate additional flood concerns
in the extended period.

&&

.CLIMATE...
Closing the books on winter season 2020-2021. Prelim data shows
Harrisburg finished as the 28th snowiest on record with a total
of 36.0 inches or +11.3 inches above the 30-year average.
Total snowfall at Williamsport ranked as the 8th snowiest
winter with 53.8 inches or +26.1 inches above the long term
mean. February was also a notable month in the snowfall category
as Williamsport (8th snowiest with 22.0 inches), State College
(11th snowiest at 25.2 inches), and Harrisburg (18th snowiest
with 19.7 inches) set notable marks. Of additional note:
February of 2021 was the snowiest February since 2014 at all
three sites.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 10 AM EST Tuesday for PAZ028-037-041-042-
046-049>053-056>059-063>066.
Wind Advisory until 7 AM EST Tuesday for PAZ005-006-010>012-
017>019-024>027-033>036-045.

&&

$$
SYNOPSIS...Banghoff
NEAR TERM...Banghoff
SHORT TERM...Banghoff
LONG TERM...Banghoff
AVIATION...Fitzgerald
HYDROLOGY...Banghoff
CLIMATE...Banghoff



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