338
FXUS61 KBGM 221806
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
106 PM EST Fri Nov 22 2024

.SYNOPSIS...
A strong low pressure system over the region today will move
offshore this weekend. Steady rain and snow this morning will
become more showery as a result. A cold frontal boundary then
brings an additional chance of rain and snow showers early next
week.

&&

.NEAR TERM /THROUGH SATURDAY/...
930 AM Update...
Show showers continue over central NY and northeast PA, with
rain showers over the northern portion of our area. Radar
imagery shows a decent snow band moving through the southern
tier of NY. Otherwise a dry slot is working its way into the
eastern portion of the region cutting off showers. Had a report
of 16 inches in Delaware and Otsego, NY. Otherwise snow totals
continue to vary across the area with elevation differences.
Made minor changes to update temperatures and dew points using
current observations.

630 AM Update...
Got a report east of Cooperstown of 14 inches.Quite a few
reports of 4-10 inches as well which seems to be the threshold
for a spike in power outages. Snow is starting to become more
showery now east of I-81 as of 5:30 am so for these locations
the storm is winding down. Still a few more hours of snow to go
near I-81 as the main snow band pivots west of the surface low.

Temperatures have been running several degrees above freezing in
the advisory areas with the typical sharper cutoff from decent
snow to near nothing. Given it is the first event of the year
and rush hour will let the advisory continue. Valleys around
Elmira, Syracuse and Rome may end up with only a dusting.

Previous discussion below.


Moderate to heavy snow bands have begun to develop east of I-81
as of the pre-dawn hours. These should progress further westward
getting to around I-81 or a bit east by rush hour. Additional
areas of snow will rotate southwestward into the region behind
the main bands which should become lighter and more showery by
the afternoon.

Steadier and moderate precipitation has been a struggle to get
much further west and I-81. As a result, the changeover to rain
in the valleys has been a slow one with Elmira and some valley
locations near Ithaca still seeing rain. Once the bands work
into these locations a changeover to snow is still anticipated
for the morning hours.

While light snow is ongoing in NE PA, the steadier and somewhat
heavier snow bands still look to work southwest into these
locations for most of the morning as well.

Overall, no changes to the headlines with the morning forecast
package. However, the delayed changeover further west may end
up resulting in trimming totals west of I-81.

The snow is elevation dependent as expected. Ratios here at our
office were 7:1 at 1,600 feet. Valley locations looking at
webcams are even having a harder time to get accumulations given
the warm ground. Meanwhile, the highest elevations have gotten
more snow on the ground fairly quickly with a spot outside
Vestal over 5 inches as of a few hours ago.

Temperatures only look to rise a few degrees today outside of
the clouds and precipitation with most spots in the 30`s. With
clouds tonight, should not see temperatures tank as is typically
the case given the snow cover with most locations falling to
around 30.

Suspect NBM pops are overdone a bit tonight and Saturday as the
main low moves into New England and another mid level
disturbance in the Great Lakes. Still maintained the chance for
some spotty rain and snow showers. Wind direction becomes more
favorable later Saturday to where some lake response may occur
off of Lake Ontario. Still looks chilly with highs near 40.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
300 AM Update

The strong upper level trough will finally get moving and slide
out of the region Saturday night. As it moves to the NE,
synoptic flow over the region shifts from northerly to more
NWerly. The 850mb temps are not as cold as earlier guidance
suggested; only falling down to around -3.5C across the area.
This will still be enough to kick off scattered lake effect
showers across most of CNY during the overnight hours.
Temperatures look to be in the low to mid 30s across the area so
we expect precip to be rain at lower elevations and valleys with
snow above 1500ft. Accumulations at higher elevations will be
minimal, with under 1/2 in expected.

Sunday will see flow shift to more WNW, pushing showers to the
north and out of the Southern Tier. Higher elevation snow and
valley rain is still expected into the early afternoon as temps
will be slow to warm, but once again, snow accumulations look to
be minimal. A ridge building into the region from the southwest
will cut off the lake effect engine, with showers dissipating
in the afternoon. Temps will top out in the upper 30s to low
40s.

The ridge continues to build into the region from the west Sunday
night, keeping conditions dry. Temps will remain cold as we
continue to have NW flow keeping the cooler Canadian airmass
overhead. Overnight lows will be in the mid 20s to low 30s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
345 AM Update

Monday will be dry and warm as high pressure moves over the
region. Afternoon temps will climb into the upper 40s to low
50s. The next storm system is expected to move into the area
Monday night in the form of a lake cutter. Timing and location
of the low is still uncertain, but it looks like we should see
precip start out as rain Mon night into Tuesday, changing to
snow by tuesday evening as a cold front moves through the
region.

Guidance is hinting at the possibility of a storm system
developing and impacting the region on Thanksgiving, but details
on timing and location are still very much up in the air. A
broad upper level trough is progged to move into the central
US Wed or Thurs, which would be the main driver of a storm
system impacting our region at the end of the week. Global
models are very unsure as to how this trough will develop, with
the GFS keeping it very flat and developing a low that misses us
to the south completely, while the Euro and Canadian show
sharper troughs that develop lows that bring snow to the region.
We will be keeping a close eye on how the models develop this
system over the weekend.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...

1245 PM Update

A mix of rain, snow and drizzle continues across the region as a
low pressure system spins over Central NY and Northeast PA.

Most of the accumulating snow is now over for our taf sites;
AVP could see up to another inch over the next 2 hours.
Widespread CIG/VSBY restrictions will continue through the next
24 hours, with a mix of MVFR, MVFR fuel alternate and even some
IFR possible at ITH, BGM and AVP.

Highest confidence is at AVP, where it looks to remain IFR/LIFR
the rest of this afternoon and evening through about 23/06z.
This will be due to light snow, fog and drizzle.

BGM looks to fluctuate between IFR and MVFR Fuel Alt over the
next 4 hours, then likely improving to just MVFR Fuel Alt this
evening and overnight. IFR may return here in the upslope NW
flow by mid to late morning Saturday.

ITH has lingering IFR light snow for the next hour, with IFR
CIGs lingering through about 22z. Then improving to MVFR Fuel
Alt, and perhaps a short window scattering out. Solid MVFR Fuel
Alt, and even IFR returns early Saturday morning, continuing
through the day.

ELM fluctuates between MVFR and MVFR fuel alternate much of the
time for the next 24 hours. There is tempo for steadier rain,
and a few wet snow flakes mixing in over the next 3 hours.
There could be a short period where it scatters out to brief VFR
overnight...with moderate confidence in returning to MVFR fuel
alternate CIGS around daybreak, through the rest of the morning
and early afternoon.

SYR and RME see on and off periods of rain fluctuating between
MVFR and VFR for much of the taf period. SYR may see MVFR Fuel
Alternate after 12z Saturday in the NW lake enhanced flow.

Winds are east-northeast 8-15 kts, becoming northwest on
Saturday.

Outlook...

Saturday afternoon and night...Continued possible restrictions
in rain and snow showers, especially Central NY.

Sunday...Gradual improvement. VFR probable for AVP with MVFR
expected elsewhere. Mixed rain/snow showers far northern areas.

Monday...Mainly VFR expected. Moderate confidence.

Tuesday...Another approaching low pressure system
could bring possible restrictions.

Wednesday...Lake effect snow and rain showers bring possible
restrictions; especially our NY terminals.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Storm Warning until 4 PM EST this afternoon for
     Paz038>040-043-044-047-048-072.
NY...Winter Weather Advisory until 4 PM EST this afternoon for
     Nyz037-018-022>024-037.
 Winter Storm Warning until 4 PM EST this afternoon for Nyz022-
036-044>046-055>057-062.

&&

$$

SYNOPSIS...MWG
NEAR TERM...ES/MWG
SHORT TERM...MJM
LONG TERM...JTC
AVIATION...JTC/MJM