914 
FXUS61 KBGM 210552
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
1252 AM EST Sun Jan 21 2018

.SYNOPSIS...
Mild conditions are expected to continue this weekend. Most
areas will likely remain dry into Sunday. Moisture will 
increase from the west Sunday afternoon, with increasing odds 
of seeing light rain showers or drizzle. As temperatures cool 
Sunday night it could freeze. Rain will become more likely 
Monday and Tuesday, as a storm system moves through the region. 
A slightly cooler airmass is expected behind the system for mid 
week, along with scattered snow showers.

&&

.NEAR TERM /THROUGH TODAY/...
1230 am update...
Temperatures again showing a wide range from around 20 to the
mid 30s. Lowered temps. Skies only have high clouds so little
insolation. Winds have become light to calm across most of the
area. 

6 PM Update...
Things are pretty quiet this evening, and forecast is in fine
shape. Other than further slowing down the eventual increase of
cloud cover overnight, and tweaking temperatures/dewpoints/etc.
for current and near-term conditions, no changes were made for 
this update.

Previous discussion...
Partly to mostly sunny skies were noted across the region at 
mid-afternoon. Observational data shows a cold front extending 
from the Upper Peninsula of Michigan into eastern Quebec. With a
primarily zonal flow indicated across our region by water vapor
bands, this front is expected to remain north of our region. 
This will result in a dry and quiet weather night across the
forecast area, along with some increasing cloud cover.

The next storm system should start affecting our region by
tomorrow afternoon. Over the next 12 hours or so, the upper-
level trough will eject into the Plains and aid in developing
surface low pressure over the High Plains by tomorrow afternoon.
A broad southwesterly low-level flow, in advance of the
approaching storm system, is expected over our region Sunday.
This will allow cloudy skies to continue through the day. 

Weak isentropic ascent (at the 295K and 300K theta levels) 
should interact with the increasing moisture to result in small
rain possibilities for Sunday. I expect the odds of seeing rain
will initially be seen over southwestern parts of our forecast
area mid- to late Sunday morning, then gradually spread
northeast through the afternoon. Most rainfall amounts should be
rather light through Sunday afternoon (generally less than 0.01
inch).

Sunday's high temperatures will likely be a couple of degrees
cooler than what we saw today given the expected increase in
cloud cover over the region.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
There will be a gradual increase in moisture through the short
term as a closed upper low and surface system spins up over the
center of the country. Earlier runs had more cold air seeping
down into New England from Ontario bringing the risk of freezing
drizzle and rain. That threat has lessened as the cold air
remains further north and east, so while there is the threat of
some freezing precip over the far east and north, very little
ice accumulation is expected. 

Despite the closed low, the system moves east and north fairly
quickly with the surface cold front passing the area by midday
Tuesday. Ahead of the front, there will be about a 6 hour period
of light to moderate rain with QPF averaging around a half inch
to three quarters. Most of the overrunning rain associated with
the warm front will fall north of the area Monday leaving the
area cloudy but mild for the first day of the work week.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Cold air advection and a northwest flow will bring lake effect snow
showers into the area into early Thursday. Air is not all that
cold, bottoming out at around -16C at 850mb, so the lake effect
will be limited to snow showers. Flow becomes more sheared with
time as the surface high drops in with a more northerly flow,
and the 850mb and 925mb northwest. Nose of the surface high will
be over the region Thursday night ending the leftovers. High
slides east as the upper ridge builds on Friday with the warm
air advection beginning again in earnest. This should allow for
temps above normal at he end of the week.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
1230 am update...

Ceilings will gradually lower late tonight from the north into
RME but little else. MVFR cigs by 09z then fuel alternate at
11z. MVFR cigs also moving in from the southwest bringing MVFR
cigs to all sites in the afternoon. Delayed the onset a little.
Ceilings further drop to fuel alternate around 00z and to IFR at
ITH/BGM. 

SW winds at around 5 kts or light and variable this morning.
This afternoon winds shift to the south but still light. 

Outlook...
Sunday overnight...Reduced flight categories are expected to 
continue. Wintry mix of precipitation possible.

Monday through Tuesday...Flight category reductions continue
under periods of RA.

Tuesday night through Wednesday...Possible continuation of
flight category reductions and a chance of SHSN.

Thursday...VFR under high pressure.

&&

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

&&

$$
SYNOPSIS...DAB/TAC
NEAR TERM...DAB/MDP/TAC
SHORT TERM...DGM
LONG TERM...DGM
AVIATION...TAC