Select Your Area NWS Weather Forecast Office
NWS Area Weather Forecast Discussion
County Warning Area [CWA]: BGM
Regional NWS Weather Office: Binghamton, NY

FXUS61 KBGM 271743

Area Forecast Discussion
National Weather Service Binghamton NY
143 PM EDT Tue Oct 27 2020

Cool unsettled weather continues through tonight with spotty
showers. Brief high pressure Wednesday yields dry and milder
conditions. A strong low pressure system will cause rain to
develop Thursday, which may mix with or change to wet snow
Thursday night into Friday as colder air overspreads the region.
Snow accumulations will be possible, especially higher terrain.


140 PM Update...
Mostly cloudy cool day in progress; highs ranging from lower
40s to around 50 in Central NY and upper 40s-mid 50s in
Northeast PA. We are still set to get a batch of showers from
a shortwave passage embedded within brisk upper flow on its way
to becoming zonal late afternoon-evening; then models have
better consolidated for another wave zipping through with
isentropic lift and moisture late tonight-very early Wednesday.
While light, rain chances have been increased considerably for
late tonight with that second wave especially Twin Tiers-
Catskills southward, before ridging is able to dry things out
mid morning through afternoon Wednesday.

Previous discussion...
Cold front has pushed southeast of the area, but still plenty
clouds and light rain showers lingering behind the front.
Temperatures will be cool today, with highs generally in the
upper 40s for most areas. Cold air advection and westerly flow
off the lakes will make for another cloudy day with some
disorganized shower activity. Surface ridge of high pressure
starts to build in from the north this afternoon and evening.
However, a midlevel shortwave pushes into western NY around 0Z
tonight and crosses the region through the overnight hours.
Another round of light rain showers will be possible tonight
with the passing wave and even some snow flakes could mix in
across the north, but conditions will start to improve as the
wave exits early Wednesday morning. Although the showers come to
and end on Wednesday, there will still be plenty of low level
moisture around. Latest guidance shows cloud cover persisting
into Wednesday afternoon, but finally scours out and some breaks
of sunshine will be possible late in the day with high
temperatures into the low to mid 50s.


An upper level low pressure system will be moving through the
southern Plains Wednesday night. Meanwhile, Hurricane Zeta will
be making landfall along the Gulf Coast. Then the remnants of
Zeta rapidly move northeastward towards the Mid-Atlantic states
per the latest NHC forecast track. These features, along with a
northern stream upper level shortwave will combine to create a
rather complex storm system for Thursday into Friday.

After a dry night Wednesday night, overrunning rainfall pushes
northward into Northeast PA and then into Central NY on
Thursday. Meanwhile, a large area of Canadian high pressure will
be building to our north. With ample moisture from the remnants
of Zeta in place, some of the rainfall may be moderate to heavy
at times Thursday and Thursday evening. Greatest chance for
locally heavy rainfall will be across the Poconos in Northeast
PA and this is where WPC has a marginal risk for excessive
rainfall in their Day 3 Outlook. Highs on Thursday will likely
be in the upper 40s to mid 50s.

The above mentioned Canadian high pressure system will dive
southward Thursday night and Friday, supplying the region with
much colder air. At the same time, the storm system will likely
be moving from the Mid-Atlantic states to off the southern New
England Coast and possibly strengthening as it does so. With
precipitation continuing across our area and the incoming cold
air, rain may mix with and eventually changeover to snow,
especially across the higher elevations of Central NY and the
Catskills. That being said, there is still a lot of uncertainty
regarding how far south and east the storm system tracks and how
much it deepens. Some models, such as the GFS continue to hint
at the storm being too far south and east to line up timing-
wise with the incoming cold air. This would limit accumulating
snow potential. However, other model and ensemble solutions
track the storm system further north and bring more accumulating
snow to the region as it would changeover quicker. With this
large amount of uncertainty, it is still too early to talk about
snowfall amounts. If there is accumulating snow, amounts will
be highly elevation dependent, as is typical with early season
snow events. This will continue to be watched as we continue to
progress through the week. Any lingering rain or snow showers
will likely end by the end of the day on Friday as the storm
system pulls away from the coast and high pressure moves in.


The main story for Friday night will be the cold temperatures.
As high pressure begins to take control, skies will clear and
winds will diminish. With a very cold airmass in place, lows
will likely at least get down to the 20s, with some areas
getting into the teens.

High pressure will bring plenty of sunshine for Saturday.
However with the chilly airmass still in place, highs will
likely only be topping out in the 40s for the majority of the
area. A cold front will then approach the area on Sunday,
bringing a chance of rain showers, especially during the
afternoon and in Central NY. Highs Sunday will likely be in the
upper 40s to mid 50s. As temperatures fall into the 30s Sunday
night, any lingering showers may mix with or change over to snow
showers. Lake effect rain and snow showers are then possible
late Sunday night into Monday morning. Otherwise, Monday looks
partly sunny with highs in the 40s.


A pair of weak disturbances will zip across the terminals during
this TAF period; one late afternoon-evening, then the other
late tonight to dawn Wednesday. In addition to moisture that
remains trapped for least minor ceiling restrictions, these
disturbances will cause further deterioration to fuel alternate
or IFR as well as some light rain and/or mist. Ceilings will
start to improve a bit after dawn Wednesday, as a ridge of high
pressure moves into the region, scattering or lifting ceilings
to higher end MVFR or even VFR. Winds will be northwest or
variable mostly under 5 knots through tonight; becoming light
southwest on Wednesday.


Wednesday afternoon through Wednesday night...Mainly VFR
courtesy of high pressure passing by just to our south,
dominating our weather.

Thursday...Restrictions expected to develop as rain moves in
from southwest to northeast from low pressure system.

Thursday night through Friday...Back end of system includes
rain mixing with/changing to wet snow; associated restrictions.

Friday night through Saturday night...Mainly VFR with high

Sunday...Frontal system moves in with a good chance of showers
and possible restrictions.





Forecast Discussion from: NOAA-NWS Script developed by: El Dorado Weather