644
FXUS61 KBGM 231804
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
104 PM EST Mon Dec 23 2024

.SYNOPSIS...
A clipper system will cross the area tonight into Tuesday with
a round of light snow. Largely dry conditions are expected
Wednesday through Friday with temperatures trending warmer later
in the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
945 AM Update...

Hourly temperatures are the biggest challenge over the next
several hours as much of the region outside of the northern
Finger Lakes to Syracuse Metro area are running several degrees
below the coldest model guidance at this hour. As a result,
temperatures were lowered across NE PA, the Southern Tier and
Catskills into the early afternoon. The rest of the forecast
remains on track heading into tonight with the approaching
clipper.

340 AM Update...

High pressure is centered over the region this morning with very
cold temperatures to start the day. Much of the region dropped
below zero overnight with the coldest readings as of 330 AM
coming in at -18F in Morrisville, NY and -15F in Walton, NY.

Temperatures will rebound some through the day as warm air
advection takes hold on southerly flow. Although, highs this
afternoon will still only top out in the upper teens to mid 20s
across the region.

A clipper system will be pushing in from the west late in the
day and tonight, with mid and upper level clouds pushing into
the region through the day. Isentropic lift ahead of the warm
front associated with this clipper system will start spreading
snowfall over Central NY by tonight and snow will slowly spread
southward through the early morning hours on Tuesday as the
systems cold front pushes into western NY. NAM forecast
soundings show the best Omega through a saturated Dendritic
Growth Zone from 6Z to 12Z Tuesday morning. During this 6 hour
period will be when snowfall rates will be most intense and the
bulk of the snowfall will occur, especially along and north of
the NYS Thruway Corridor.

A potent shortwave and associated surface cold front swings
through the region Tuesday morning and the heavier snowfall
will dip south and east across the area through the morning,
exiting by late Tuesday morning or early afternoon. A winter
weather advisory has been posted for portions of the region in
our northern forecast area (see weather.gov/bgm for details).
This system will bring widespread light snowfall, with most of
the area receiving 1-3 inches, but the highest amounts will be
north of the Southern Tier and into Oneida County, where 3-6
inches will be possible.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
300 AM Update...

Ridging will be building in for Christmas though with snow
cover and cold air in place, temperatures will remain below
freezing Christmas. The surface high in place begins to slide
east Christmas night into Thursday with return flow setting up.
The GFS and the ECMWF both are showing a fairly potent
vorticity maximum moving through at 500 mb Thursday. Ensembles
are not as bullish with it but there is still a subtle kink in
the 500 mb flow Thursday so there are plenty of members picking
up on something as well. There is almost no moisture for this
shortwave to work with so chances of precipitation were capped
at 15%.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
300 AM Update:

The long term is looking warmer but despite the increasing 500
mb heights and persistent warm air advection, temperatures will
be slow to moderate. The snow cover as well as the low sun
angle makes it tough to get much heating. It will take almost to
the weekend to get temperatures to rise above average despite
the above average 500 mb heights well above climatology for most
of the week. Next weekend is looking more active as the flow
becomes more meridional with strong SW flow. Ensembles all have
a spattering of surface lows or shortwaves moving through
Saturday through Monday. Given all the differences in timing,
chances of precipitation were capped at 50% but spread out over
more periods to encompass the range of solutions. There is some
better certainty in the precipitation types as at least for the
weekend, ensemble mean 850 mb and 925 mb temperatures are above
freezing so rain would be likely for at least the beginning of
the precipitation with any system that moves in. A larger
pattern shift is looking more likely as we head into the new
year with ridging returning to Alaska and potential blocking in
the North Atlantic that would help filter colder air masses into
the eastern US.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR conditions are expected to remain in place at all terminals
through early this evening with increasing clouds. A clipper
system moving into the area will lead to the development of snow
across the NY terminals from northwest to southeast between
03-06Z with at least MVFR ceilings and visibility dropping to
IFR or worse after midnight when it is expected to become its
steadiest and heaviest for a 3-4 hour period. Snow is expected
to reach AVP around 09Z with at least IFR restrictions possible
prior to daybreak between 10-12Z.

After the steadiest snow comes to an end by 10-12Z across the
terminals, there can be some lingering snow showers or flurries
and low ceilings keeping MVFR to fuel-alt restrictions in place
through the rest of the TAF period.

Guidance does support the development of SW LLWS this evening
between 00-01Z as a warm front lifts north through the area with
confidence highest at ELM, BGM and ITH. LLWS is more borderline
at SYR and AVP so these terminals will be closely monitored.

Outlook...

Tuesday afternoon...Restrictions possible, mainly due to lower
ceilings, especially for the NY terminals.

Wednesday through Saturday...Mainly VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Winter Weather Advisory from 7 PM this evening to 1 PM EST
     Tuesday for NYZ009-017-018-036-037-044>046.

&&

$$

SYNOPSIS...MPK
NEAR TERM...DK/MPK
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...DK/MPK