407 
FXUS61 KBGM 062319
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
619 PM EST Sat Feb 6 2021

.SYNOPSIS...
After a mostly clear evening, a coastal storm system and a
weaker system moving through Central NY will bring snow to the
area on Sunday, especially during from the late morning to the
early afternoon. Lake effect snow showers then develop east of
Lake Ontario Sunday night into Monday. Colder weather is 
expected next week with multiple passing disturbances and 
resultant chances for snow.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...

Only minor to temperatures and dewpoints with this update. It
appears that the 18Z model suite for Sunday is trending further
southeast. This will be evaluated for the next update. Previous
discussion below. 

After a breezy day, winds will quickly diminish this evening.
This combined with initially mostly clear skies and a 
widespread snow cover will result in radiational cooling 
conditions and rapidly falling temperatures this evening. 
Temperatures begin to level off a bit after midnight as clouds 
increase ahead of the next system. Lows will likely be in the 
teens, with some single digit readings across the higher 
elevations of Central NY and northern Oneida County.

On Sunday, a strengthening coastal low pressure system will
quickly track from off the North Carolina coast to off the 
southern New England coast. Meanwhile, a separate shortwave will
swing from the Great Lakes through Central NY. While the 
expected track of the coastal low has shifted slightly further 
north and west the last few days, the greatest impacts from snow
still look to be south and east of our forecast area (closer to
the coast). That being said, our two eastern-most counties 
(Pike and Sullivan counties) will likely be close enough to see 
3-5 inches of snow, especially across the eastern half of these 
counties. Snowfall rates there may approach 1 inch per hour at 
times late Sunday morning into the early afternoon. Expected 
snowfall amounts decrease further west. Generally 2-4 inches of 
snow is expected for the rest of the Poconos. Should this 
coastal low track a bit further north and west than expected, 
snowfall amounts may end up being a bit higher, especially for 
Pike and Sullivan counties. With this forecast package, we have 
issued a Winter Weather Advisory for Pike, southern Wayne, 
Lackawanna, and Luzerne counties in PA; Sullivan County in NY.

At the same time, a shortwave will be moving through Central NY.
This will bring a round of light snow to much of the rest of the 
region with generally 1-3 inches of snow expected. Otherwise,
snow from these two systems gradually tapers off by the late
afternoon, before lake effect snow showers in portions of
Central NY begin. Highs on Sunday will be mainly in the upper
20s to lower 30s.

While the majority of the area dries out Sunday night, a west-
northwesterly flow will bring some scattered lake effect snow
showers for the Finger Lakes Region to the NY Thruway corridor.
An additional inch or two of snow will be possible. Aside from
the associated lake effect clouds for these regions, a general
clearing trend is expected overnight. Lows will likely be in the
single digits to lower teens.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Some lake-effect snow will remain possible Monday across areas east 
of Lake Ontario in wake of Sunday's quick-moving storm system. The 
greatest odds of seeing additional accumulations will likely occur 
during the morning, before a weak surface high moves east of the 
region Monday night.  Additional snowfall amounts of an inch or less 
are expected.

Southerly winds should return Monday night as the surface high moves 
to the east.  Low-level moisture will increase and isentropic 
upglide will approach from the south/west ahead of the next in a 
series of fast-moving weather systems.  The result will be another 
possibility of snow (especially) from late Monday night and continue 
through most of Tuesday as the storm system moves across the 
forecast area. 

Weak perturbations, embedded in the upper-level, flow will interact 
with any remaining moisture as they continue traversing the region. 
So even though the storm system is expected move offshore, we'll 
still see some lingering lake-effect snow probabilities continue 
into Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A relatively low-amplitudinal weather pattern is expected to remain 
across the forecast area for the end of the week, as an upper low 
spins around in the Canadian Prairies.  This will allow an unsettled 
weather pattern to continue during the Day 4-7 period with at least 
a small possibility of snow just about every day.

There's some indication that the upper-level flow will amplify 
across Mid-America as a couple of disturbances rotate around the 
upper low.  The first piece of energy will likely aid in the 
development of low pressure near the spine of the Appalachians, 
probably somewhere around the Tennessee Valley.  Meanwhile, a 
second, possibly stronger piece of energy may dive into the Northern 
Plains toward the end of the week.  This could lead to the storm 
system strengthening as the surface low heads northeastward and 
starts to interact with the (possibly) stronger upper-level support.

Honestly, there's lots of uncertainty in the timing/evolution of 
this end-of-the week storm system.  For now, it looks like the odds 
of seeing snow will likely increase Thursday and continue through 
most of Friday as the storm system moves across the forecast area. 
By next Saturday, the snow machine will likely transition to more of 
a lake-effect setup.  Given the uncertainty, I don't plan on 
straying too far from the model blend.  Time will tell, though. Stay 
tuned.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
Mainly VFR conditions are expected until around 12Z or so. A
storm off the Mid-Atlantic coast along with a separate weaker 
system swinging into Central NY will then bring snow to the area
and associated IFR visby restrictions. KAVP will be the first
terminal to see these restrictions (around 12Z), shortly
followed by the remainder of the terminals. KSYR and KRME will
likely be the last two terminals to go down to IFR, which will
occur by late Sunday morning. While IFR visbys are expected, 
ceilings will likely be MVFR or Fuel Alternate.

Winds this afternoon will be 10-15 knots, with occasional gusts
up to 20 knots. Winds quickly diminish by the late
afternoon/early evening, becoming light and variable overnight.
Then mainly southeasterly winds at less than 10 knots Sunday
morning. A brief period of weak LLWS will also be possible at
KELM early Sunday morning.

Outlook...
Sunday afternoon...Northern edge of a storm will continue to 
bring light snow and restrictions to all terminals.

Sunday night through Monday...Scattered lake effect snow showers
may bring some occasional restrictions to the Central NY
terminals, mainly KSYR and KRME.

Monday night through Thursday...Scattered snow showers and 
associated restrictions from a couple of clipper systems 
passing through, and lake effect snow showers.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 6 AM to 7 PM EST Sunday for 
     PAZ044-047-048-072.
NY...Winter Weather Advisory from 6 AM to 7 PM EST Sunday for 
     NYZ062.

&&

$$
SYNOPSIS...BJG
NEAR TERM...BJG/MWG
SHORT TERM...DAB
LONG TERM...DAB
AVIATION...BJG