216
FXUS61 KBGM 051751
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
1251 PM EST Wed Feb 5 2025

.SYNOPSIS...
Scattered lake effect snow showers and flurries taper off early
this morning as dry and cold high pressure builds into the area.
Another low pressure system tracks into the region Wednesday
night bringing a mix of snow, sleet and freezing rain for
Thursday.

&&

.NEAR TERM /THROUGH THURSDAY/...
1100AM Update...

After digging into the approaching high and wind fields based on
it, increased PoPs for snow showers out of the NW across the
Finger Lakes region through the mid afternoon hours. Low level
lapse rates combined with a very shallow moisture layer should
allow scattered snow showers/flurries to occur into the
mid-afternoon hours.


915 AM Update...

Finger Lake effect snow has continued south of the lakes this
morning longer than expected but should weaken into flurries in
the next hour or so. High pressure will build in from the west,
keeping NW flow and partly to mostly cloudy skies, especially
for areas downwind of the lakes. The rest of the forecast
remains on track.


3 AM Update...

High pressure will push into the region today and this will
bring an end to the lake effect snow showers this morning. Today
will be cold and dry, with surface high pressure moving
overhead. High temperatures will only climb into the low to mid
20s for most of the region. Tonight will be another cold one,
but a non-diurnal temperature trend is expected overnight with
low temperatures likely occurring around midnight and then
rising as warm advection kicks in early Thursday morning. Warm
frontal precipitation pushes into the area early Thursday
morning and prior to sunrise, most of the of the precipitation
is expected to be all snow. Soundings do suggest cold air
damming will be an issue with this event as the warm nose
punches in aloft and cold air stays locked in at the surface.
The depth of the cold air will be the main factor in determining
sleet vs freezing rain and trends are leaning with more sleet,
so have pulled back on ice accumulations a bit with this update.

Finally, decided to expand the winter weather advisory to
include the whole area, as a wintry mix is looking likely. Still
some uncertainty with p-types, however, the threat of some
light icing just about everywhere is high enough that expansion
of the advisory was necessary.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
330 AM Update...

With the surface low well to the east and the upper level
trough axis through the region by Thursday evening, cold air
advection takes over. 850 mb temperatures fall into the teens
below 0C as well as strengthen to 40 to 50 knots. The boundary
layer lapse rates will be fairly steep but not quite dry
adiabatic so that will help limit the amount of wind that mixes
down but widespread 25 to 35 mph winds gust are likely
overnight. Lake effect snow develops off of Ontario with a multi
lake connection possible given the cyclonic flow through the
Great Lakes. Soundings sampled from within the lake effect band
does have steeper low level lapse rates thanks to warming from
the lakes so higher wind gusts are likely within the band along
with the heavy snow. If the multi lake connection and westerly
winds over Ontario persist, there is the possibility of a strong
organized band to form for at least several hours Thursday
night into Friday morning.

Models are consistent with a 500 mb shortwave passing to the
north Friday so the lake effect band should shift south out of
Oneida into the NY Thruway corridor though some directional
shear through the boundary layer may disrupt the lake effect
snow bands making them more cellular. The lake effect snow
drifts back north Friday night into Saturday as upper level
ridging builds in ahead of our next system. Weakening boundary
layer winds will also shrink the inland extend of the band with
its northward progression with the heavier snowfall closer to
Lake Ontario.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
330 AM Update...

The long term starts with another area of low pressure moving
up the Ohio River Valley Saturday night into Sunday. A strong
jest streak nosing in from the Great Lakes will support a
deepening low. Strong high pressure to the north has helped
suppress this system more over the last few model runs with
deeper cold air in place. Given the cooler trend, the wet bulb
aloft populated from just blending GFS and ECMWF coupled with
surface temperatures was used to create ptypes. The wetbulb in
this blend stayed below 0 for most of NY but did nudge above
freezing in NEPA. The refreeze later in forecast soundings is 3
to 4 thousand feet thick so sleet is becoming more likely than
freezing rain. QPF in this system is much better than many of
the recent storms as moisture from the gulf is able to flow up
through the central US for the first time in over a month with a
stronger Bermuda high. Ensembles are approaching 40% chance at
most of the forecast area could see half inch of liquid between
Saturday night and Monday.

Once this system is out to sea early next week, we once again
get strong cold air advection with 850 mb temperatures falling
enough for lake effect snow to develop once again. Mid next week
is another time frame to watch as there is a trough ejecting
from the intermountain west with a southern shortwave near TX
and one passing through the northern plains. Ensemble low
pressure centers do have a handful of members that have deeper
lows in and about the northeast though most dont even have lows.
Still given the ejecting trough and a strengthening subtropical
jet, there will be good baroclinicity setting up through the
central US and east coast so it bares watching.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Mostly VFR through the evening hours except for ITH, where some
lake effect clouds and snow flurries will linger for a few
hours, keeping ceilings MVFR.

Tonight into the morning, a wintry mix of snow, sleet and
freezng rain/drizzle will spread across the region from SW to
NE. Currently, AVP is the only terminal where confidence is high
enough for IFR conditions to occur. ELM/BGM/ITH are showing IFR
signals, but the changeover to sleet from snow might be faster
than expected given variance in guidance, which would keep
conditions MVFR. Hopefully this will become more clear in the
next forecast. Freezing rain and drizzle are expected for a few
hours at the end of the TAF period at AVP/BGM/ELM/ITH. SYR and
RME will see snow showers through the period, with MVFR
conditions expected.

LLWS is expected at AVP/BGM/ELM/ITH during the morning hours out
of the south up to FL020 between 35-45kts.


Outlook...

Thursday afternoon... Restrictions will end from west to east
as precipitation moves out of the region. Possible LLWS.

Thursday night thru Friday...Lake effect snow showers likely in
a northwest flow; associated restrictions, especially SYR, ITH
and RME.

Saturday...Mainly VFR, with exception to RME and SYR, which may
be impacted by lake effect snow showers.

Sunday...Chance of rain/snow showers and associated
restrictions.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 4 AM to 4 PM EST Thursday for
     PAZ039-040-044-048-072.
     Winter Weather Advisory from 1 AM to 1 PM EST Thursday for
     PAZ038-043-047.
NY...Winter Weather Advisory from 4 AM to 4 PM EST Thursday for
     NYZ009-015>018-023-025-036-037-044>046-056-057-062.
     Winter Weather Advisory from 1 AM to 1 PM EST Thursday for
     NYZ022-024-055.

&&

$$

SYNOPSIS...MPK
NEAR TERM...MPK
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...JTC