639 
FXUS61 KBGM 261946
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
246 PM EST Mon Feb 26 2018

.SYNOPSIS...
High pressure will build across the region tonight and Tuesday
with fair and mild weather for late February. A frontal system
will reach into the eastern Great Lakes Wednesday bringing a
chance for rain showers mainly in central NY and the northern 
tier of eastern PA. A large storm system is projected to affect 
the region late this week. This storm could bring significant 
rains and even some snow or snow showers to our area.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
Visible satellite imagery shows some lingering cirrus across the
Poconos to the southern Catskills with just a few cumulus
clouds that have popped up in upstate NY. Water vapor imagery 
shows a well defined upper level wave moving through NY and PA
which will be east of the region for tonight. This will pull the
cirrus east with it as the cumulus fades off by sunset. Hence
tonight should be clear as high pressure builds across the
middle Atlantic and northeast U.S. 850 mb temperatures and
1000-500 mb thicknesses suggest above normal temperatures for 
tonight with lows in the 20s and lower 30s. 

The surface high pressure slides east of the region by Tuesday
afternoon as a southwesterly milder return flow sets up.
Maximums on Tuesday look to be well above normal into the low
and mid 50s under mostly sunny skies. 

Cirrus from the next system begins to overspread north central
NY Tuesday night as warm air advection begins. Since the 
atmosphere will be so dry to begin with, there won't be any 
precipitation through Tuesday night. The mild weather will 
continue as lows Tuesday night will be well above normal with 
lows in the upper 20s and 30s. 

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... 
225 PM Update... Mild, southwesterly flow will continue on 
Wednesday. A minor amplitude short wave along with some deeper 
moisture looks to affect the western and northern portions of 
the forecast area with a glancing blow of precip during the 
afternoon and evening hours Weds-Weds night. Will go with chance
PoPs for showers from the Finger Lakes region to the Upper 
Mohawk Valley, mixing with some snow showers at night across the
southern Tug Hill. In the meantime, a potent northern stream 
wave is forecast to dig across the Upper Midwest, forming a 
modest cyclone over the Ohio Valley. Models are in reasonably 
good agreement that this cyclone will continue to deepen as the 
energy transfers to the mid-Atlantic coastal waters by Friday 
morning. Details are never highly confident in these energy 
transfer systems, but at this time, our forecast area looks to 
be broadly positioned within the cold conveyor to the north of 
the system, and beneath favorable jet dynamics. Preliminary 
indications suggest the best forcing resides over NEPA and the 
Southern Tier counties in NY, but some model spread makes this 
forecast still uncertain, at least to where the heaviest QPF 
will be. Boundary layer temperatures suggest mainly a rain 
event, but we will have to monitor the precipitation 
microphysics parameters a bit more closely as colder air is 
drawn into the region by early Friday morning. Have maintained a
mix of rain or snow in the forecast after about midnight 
Friday.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
225 PM update... 
As the storm system pulls out to sea on Friday, colder air will
help to change over lingering rain into snow showers, 
especially Friday night. Daytime temperatures on Friday still 
appear as though they will reach the lower 40s to support mainly
rain, although higher terrain may still see some wet snow at 
times. Too early for accumulation calls at this time with 
ensembles indicating a range from no snow, to one, or two, 
outlier solutions approaching 8-10 inches. Colder air becomes 
entrenched going through Sunday with a deep northwesterly flow 
established between the building ridge across the Midwest and 
departing closed low in the Western Atlantic. Multi-band lake 
effect snow plumes are possible, although lake instability is 
only conditional with plenty of diurnal mainland instability 
available to disrupt organized banding. Scattered snow or mixed 
rain showers seems reasonable on Saturday and Sunday before the 
main high pressure axis moves overhead for Sunday night into 
Monday. Blended guidance suggests the next disturbance will be 
approaching later in the day Monday, but not quite close enough 
to mention precipitation again until Monday night.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
This afternoon and tonight: VFR throughout the TAF period. Some
wind gusts around 20 knots from the west and northwest are 
expected throughout the afternoon before decreasing around 
sunset. Winds may go more light variable than shown in the TAFS 
around sunrise. Also, fog looks rather unlikely tonight with 
drier air moving into the region. High confidence. 


Tuesday: VFR, westerly wind gusts will be possible again 
tomorrow from 15 to 20 knots. However, conditions tomorrow 
afternoon look a little more marginal than today for the wind 
gusts. High confidence. 

Outlook... 

Tuesday night-Wednesday...Generally VFR.

Thursday and Friday...Restrictions may develop in rain, or 
mixed precipitation.

Saturday... Restrictions still possible with rain and/or snow 
showers.

&&

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

&&

$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...MWG/RRM