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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 012256
AFDCTP

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

.SYNOPSIS...
March 2021 coming in like a lion. An arctic blast to kick off
meteorological spring will drive potential for snow squalls
across the western and northern Alleghenies later this
afternoon through the evening commute. Conditions will turn
sharply colder tonight with blustery northwest winds sending
temperatures plummeting 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 /THROUGH TUESDAY/...
In the wake of this mornings leading cold FROPA, a secondary
arctic front pushing southeast from the lower Great Lakes will
bring the potential for isolated brief snow squalls across the
northern and western Alleghenies between 4 and 10 PM. The
primary areas of concern are along and north of I-80 and along
and west of I-99. CIPS guidance has been bullish on SNSQ
potential for the last 2 days so we are ramping up risk
communication/DSS messaging heading into tonight. Flash freeze
threat is also relatively high given sharply falling temps and
residual road treatments washed away by recent rainfall.

Blustery winds from the NW with peak gusts over 40mph will
deliver a sharply colder airmass into CPA tonight. Temps will
fall about 15 to 30 degrees from todays highs and bottom out in
the low teens and 20s by daybreak Tuesday. Wind chills are
forecast to reach the single digits in most areas with subzero
readings most likely across the northern tier. Overall, a rather
frigid start to the end the first day of meteorological spring.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH 6 PM TUESDAY/...
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.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
By Wednesday, a southern stream wave of low pressure will stay
well south of the Commonwealth, with dry conditions persisting
but some high clouds filtering the sunshine. Southwesterly flow
will help push temperatures into the low 50s across the south
central mountains.

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 Saturday with coldest temps
aloft and northwesterly flow.

By Sunday, milder temperatures are on our doorstep, with
potential for a ridge of milder air to settle in. The
persistence of the upper trough combined with the potential for
cold air damming to persist could temper our hopes for mild
conditions, but optimism reigns supreme following the seemingly
never-ending stretch of winter weather.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Blustery west-northwest /290-310 degrees/ wind gusts 25-35kts
will impact CPA airspace through tonight. A secondary cold front
will sweep through the region early this evening, accompanied by
snow showers and brief IFR vsby in a few locations across the
Allegheny Plateau. 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-Sat...VFR/no sig wx.
-- End Changed Discussion --

&&

.HYDROLOGY...
Hydro response is on the decline with most streams and creeks in
receding mode. The latest stage at Confluence has dropped below
minor flood stage and will be canceling the warning. Other
streams in the Juniata and Lower Mainstem Susquehanna tribs
crested near or just over action stages and will continue
falling through tonight.

&&

.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. Monthly and seasonal climate summaries will be issued in
the next day or so.

&&

.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...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Lambert/Banghoff/Travis
AVIATION...Fitzgerald/Evanego
HYDROLOGY...
CLIMATE...