000
FXUS61 KBGM 260840
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
440 AM EDT Mon Oct 26 2020

.SYNOPSIS...
A system from the south will bring rain showers into the region
today and into tonight. Tuesday will remain seasonably cool and
mostly cloudy with a few lake effect rain showers around.
Wednesday will be dry and warmer under partly sunny skies.
Unsettled and cooler weather likely returns for the end of the
workweek, as yet another storm system approaches

&&

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

Light rain and drizzle is around the area this morning as a
weak surface low and an inverted trough move northeast up the
East Coast.

Another weak low moves through Western NY later this morning
along a stationary frontal boundary. The surface trough and
upper level divergence will combine for the most lift across the
NY Thruway corridor today. This is where steady, light rain
should continue through much of the day. Further south, across
the Twin Tiers and NE PA any steady light rain tapers to a few
showers or pockets of drizzle later this morning and into the
afternoon hours. Remaining mostly cloudy to overcast areawide
all day. Then, the cold frontal boundary starts to shift south
and east slowly by late afternoon...moving from the Finger Lakes
to the I-81 corridor in CNY by sunset. Behind this boundary,
surface winds shift northwesterly, and additional showers or
drizzle develop. Seasonably cool today, with highs only in the
50s. Rainfall amounts through sunset are forecast to range
between a 1/4 to 1/2 inch north of US-20 in CNY, then further
south across the rest of CNY/Southern Tier expect 1/10 to 1/4
inch....fading to less than 1/10th of an inch in NE PA.

Tonight: the front and low move off the coast setting up cold
air advection across the area. Rain showers and patchy drizzle
start to taper off across most of the area by midnight. Late
tonight 850mb temperatures get cold enough for some lake effect
rain showers to develop off of Lake Ontario in the NW flow
regime. These showers will mainly be around the Northern Finger
Lakes and Syracuse area. Overall, light QPF expected around
1/10th of an inch or less. Further south across the rest of the
forecast area...remaining mostly cloudy with isolated showers
possible. Another cool night, with lows in the mid-30s to lower
40s in most locations. Cannot rule out a few wet snow flakes
mixing in for the higher hills south of Syracuse and the
southern Tug Hill Plateau region of northern Oneida...but no
accumulation.

Tuesday: Southwest flow aloft continues, with a few mid level
perturbations working through the fast moving jet. However, in
the lower levels of the atmosphere the cool, NW flow continues
over the region. As for sensible weather....with 850mb
temperatures still around -4C expect more lake effect rain
showers around the Syracuse and NY Thruway area much of the
day. Further south, it looks to be mostly cloudy with mid level
clouds streaming overhead...but generally dry from the Twin
Tiers south into NE PA. With that said, late in the day....close
to or just after sunset another weak wave races into the
region, perhaps bringing a few showers to much of the forecast
area. With cold air advection continuing, it is forecast to be
cooler than average, with highs only in the upper 40s to lower
50s.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A weak mid level impulse will cross the region Tuesday night
with isolated rain showers and we could see some snow
showers/flurries before midnight Wednesday across our northern
forecast area.

High pressure temporarily builds into the region on Wednesday
through Wednesday night with quiet weather. Highs on Wednesday
will be near normal values, in the mid 50s. Clouds will be on
the increase by early Thursday morning from the south, as our
next system approaches, but any rain from this system should
hold off until later in the day on Thursday.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...

The main focus is on the storm at the end of the week. Stacked
upper low will push east out of the Plains Thursday morning
and weaken into an open wave as it enters the Mid Atlantic early
Friday morning. Latest model suite shows moisture from Tropical
Storm Zeta merging with the upper low as it pushes towards the
East Coast on Friday. Overrunning rainfall pushes northward
into NE PA and then Central NY during the day Thursday.
Meanwhile, a cold Canadian high pressure starts nudging in from
the north Thursday evening as the surface low crosses the
Appalachians.

Ensembles and deterministic models are in fairly good agreement
with the first round of rain coming in on Thursday/Thursday
night, with possibly an inch or more rain possible. From there
however, model guidance starts to diverge with solutions. The
Euro has low pressure intensifying along the East Coast on
Friday with a nice wrap around band of moisture while pulling
in cold air from the north and changing rain over to snow as far
south as the Twin Tiers. The GFS and GEFS mean are a bit
further south and east with the low pressure track, and although
it eventually pulls colder air in, the available moisture is
too far east by that point. For now, we will just have to
continue to watch and see how the forecast unfolds in the coming
days as a lot of questions still remain given the behavior of
several variables that will come into play for this storm.

The low eventually will exit the area on Friday with high
pressure building in behind it and that should remain over the
region through the weekend with a warming trend. If any snow
does come out of this system, at least the good news will be
that it will not hang around long.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
MVFR conditions currently across much of the area, dropping to
fuel alternate required by 09z. Occasional IFR conditions
expected at BGM, RME and AVP through 13-15z this morning. CIGS
should briefly lift to fuel alternate required areawide late
morning and early afternoon. Then, a weak frontal boundary moves
in from the NW later this afternoon. Behind this front,
CIG restrictions are forecast to quickly drop to IFR and even
alternate minimums after 19-20z at RME/SYR...21z at ITH/ELM...
21-22z at BGM and 23-24z at AVP. VSBYs will be 2-5SM in -shra,
-dz and br. Conditions remain at this level through the evening hours.

Light southeast winds this morning 5-10 kts...before veering to
southwest early afternoon, then quickly shifting northwest
late afternoon into the evening hours.

Borderline LLWS near or at ELM and ITH 09-14z this
morning...with SW winds 35-40kts at 2k ft agl expected.


Outlook...

Tonight...MVFR/IFR Restrictions likely in showers.

Tuesday through Wednesday...Mainly VFR, but stray showers may
lead to brief restrictions.

Thursday...Restrictions possible in periods of rain.

Friday...Mainly VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$
SYNOPSIS...MJM
NEAR TERM...MJM
SHORT TERM...MPK
LONG TERM...MPK
AVIATION...BJT/MJM