000
FXUS61 KBGM 271705
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
1205 PM EST Fri Nov 27 2020

.SYNOPSIS...

A weak disturbance moving through the region wil set off light
showers into Saturday, before a stronger storm pulls rain into
NY and PA early next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
Mesoscale models and recent trends do show an absence of showers
at least through mid morning. Any shower chances were removed
through mid-morning with the sunrise update.

Several mid-level disturbances will move through the area today
and continue to do through most of Saturday. This keeps around
the chance of some spotty showers or drizzle. Mesoscale modeling
has keyed in on the Finger Lakes northeast to the NY Thruway
corridor has having the highest coverage of this activity.
Overall, activity looks very spotty today then the chances
increase tonight with a stronger shortwave and secondary cold
front moving through. Mid-level heights begin to rise on
Saturday slowly turning off the spotty showers. Any showers
should linger the longest Saturday north of the Thruway where
lake moisture could be a factor with light westerly winds.

After warming to around 50 today, lows tonight only fall back
into mid and upper 30`s tonight due to clouds and spotty
showers. Even if temperatures do reach freezing in spots modeled
soundings indicate the lack of ice crystal formation needed for
snow. Thus, freezing drizzle would occur. This possibility looks
highly unlikely though at this time. The passage of the
secondary cold front brings in slightly cooler air with highs
staying in the 40`s Saturday. Bufkit Analysis momentum transfer
does show the potential for some west to northwest wind gusts
around 15 mph Saturday afternoon too.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
350 AM Update...
The weekend ends quietly, but rain will quickly race in with a
low pressure system on Monday.

Low level flow will back to light southwesterly Saturday night
into Sunday, as we get into return flow of weak high pressure
that translates from the Central Appalachians through the
Midatlantic Coast. The air mass will be dry and slightly milder.
Clearing sky Saturday night will allow radiational cooling to
put temperatures in the upper 20s-lower 30s, but sunshine will
push them about 6-8 degrees above average on Sunday with highs
of mid 40s to lower 50s.

Northern stream upper trough digs into the Upper Midwest to Western
Great Lakes Sunday night into Monday, picking up southern stream
disturbance and initiating cyclogenesis. Models are trending a
bit faster with the ejection of the resultant deepening low
pressure, while tracking it into our vicinity on Monday. It will
have a moisture connection to the Gulf of Mexico. Confidence
thus remains very high for rain to quickly overspread our region
first thing Monday. However, with the more progressive trend
noted in the guidance, it will also exit fairly quickly later
Monday, eventually placing us into a dry slot. Overall we still
appear very likely to get at least a half inch of rain, with
some orographic enhancement via southeasterly jet against
Poconos-Catskills getting some spots over an inch, but the speed
of the system should cap things from getting any higher. Just a
few spotty showers, if anything, are anticipated Monday night
in the dry slot of the system.

Temperatures will dip into 30s-near 40 Sunday evening, but
clouds will stream in as the system approaches, and temperatures
will also increase late Sunday night. This should prevent
anything other than rain as precipitation overspreads the region
early Monday. Then during the day, it will be a breezy and very
mild final day of the month with highs well into the 50s. With
the low blowing into the area Monday and then hanging up to our
north or northwest, cool air advection will drop temperatures
to lows of mid 30s-mid 40s by dawn Tuesday.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
415 AM Update...
Temperatures settle back to near average values for the start
of December, during the middle of next week, with some potential
of lake effect precipitation yet also uncertainty.

Quite a bit of model spread exists during the middle of next
week, even in the bigger picture. Models overall have somewhat
departed from the very large stacked and stuck low pressure
system that had been suggested in prior runs the last couple of
days. It remains an amplified pattern, but models dislodge the
cutoff low and/or in time tangle it with other features. About
the only thing that can be said with more confidence, is that
temperatures will be fairly close to average and thus cooler
than earlier in the week.

Temperatures are likely to fall during the day Tuesday, as cold
air advection from the southwest undercuts the low pressure. As
a pool of wraparound deeper moisture moves through Tuesday-
Tuesday night; there will be a chance for showers which, while
starting off mainly rain, could mix with wet snow.

The biggest point of uncertainty in the longer term, is whether
the broad low will dislodge too far northeast for lake effect
Wednesday-Thursday as per the ECMWF, or if instead cyclonic
flow will persist to be more favorable for some lake effect snow
as per the GFS and to a lesser degree the Canadian model. For
now, forecast maintains 20-50 percent chance for snow showers
east to east-southeast of the lakes during the second half of
the week. This will have to be sorted out better in coming days.

&&

.AVIATION /17Z FRIDAY THROUGH TUESDAY/...

Ceilings will range from MVFR to VFR through Saturday morning as
persistent clouds hold over the terminals. Winds will be light
through tonight, then gust between 15 and 20 knots Saturday
afternoon.

Some clearing is expected Saturday afternoon and evening with
VFR conditions developing.

Outlook...

Saturday afternoon through Sunday... Some continued
restrictions with drizzle, showers and low clouds at times
through Saturday. Mainly VFR Saturday night and Sunday.

Sunday night... Restrictions possible late with rain
approaching the region.

Monday through Tuesday...Restrictions likely with rain showers
mixing with snow by Tuesday afternoon.

&&

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

&&

$$
SYNOPSIS...DJP
NEAR TERM...AJG/MWG
SHORT TERM...MDP
LONG TERM...MDP
AVIATION...DJP

NWS BGM Office Area Forecast Discussion