Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS61 KBUF 162226

Area Forecast Discussion
National Weather Service Buffalo NY
526 PM EST Tue Jan 16 2018

Light snow will fall across portions of Western and North Central
New York through Wednesday as a weak storm system passes through.
Colder air behind this system will generate light lake effect snow
east of the lakes Wednesday night through Friday before a pronounced
day to day warming trend commences for the start of the weekend and
into early next week.


Some light snow will be found over western New York this evening...
as some weak low level convergence associated with an inverted
surface trough will combine with some upper level lift supplied by a
140kt H25 jet over New England to produce some deep...albeit weak
synoptic lift over the region. While all areas should pick up an
inch or so of accumulation by 10 PM...somewhat higher amounts can be
expected east of the Genesee Valley in the vcnty of a deeper plume
of moisture. Have bumped pops by some 20-30 points in many areas for
this evening. As we push through the night...the surface trough will
push will the aforementioned plume of moisture. This will
allow the steadier snow to taper off and end as flurries.

As we push past midnight...our attention will turn towards
insignificant lake snows. Cold advection will send H85 temps into
the minus teens c...and this will awaken the mesoscale processes
over Lakes Erie and especially Ontario. Expect little accumulation
off a mostly frozen Lake Erie, but southeast of Lake Ontario, where
lake induced equilibrium levels rise to 6-7K feet, several
additional inches of snow will be possible within the lake effect

Temperatures will average 5-10 degrees below normal, with lows
tonight in the single digits to mid teens and highs tomorrow in the
upper teens to lower 20s.


Wednesday night a weak shortwave will move east across Quebec, too
far north to have any direct influence on our region. The main
concern Wednesday night through Thursday will be some ongoing
limited lake effect snow, mainly off Lake Ontario. Lake induced
equilibrium heights will be very low, around 5K feet through the
period. Even so, ample low level moisture beneath the inversion and
a shallow layer of dendritic crystal growth should still be able to
support some limited lake snows. Outside of lake effect areas it
will be mainly dry, with variable amounts of clouds Wednesday night
and Thursday.

Off Lake Ontario...

Weak lake effect snow showers over central Jefferson County
Wednesday evening will drift south into the Tug Hill region
overnight, and may see a minor uptick in intensity overnight. Expect
additional accumulations of 2-3 inches across the higher terrain of
the Tug Hill, and 1-2 inches across lower elevations surrounding the
Tug Hill. On Thursday the lake effect snow will remain centered on
the Tug Hill, and should slowly weaken and possibly end through the
day as inversion heights lower even further.

Off Lake Erie...

A few flurries or light snow showers may linger Wednesday night
northeast of the lake in the Buffalo Metro area. The combination of
low inversion height and small amount of open water should keep this
very light, with just a spotty dusting of accumulation possible.
This should end by Thursday morning as the inversion lowers further.

Thursday night and early Friday a pair of sharp mid level shortwaves
will cross the region. These features will be continental and
moisture starved with only weak surface reflections. Given the lack
of moisture, expect just a few scattered snow showers across
portions of the region. They will produce a little better
environment for lake effect again east of Lake Ontario, with deeper
moisture and a little higher inversion height. This may produce a
few more inches of accumulation across the Tug Hill region later
Thursday night and Friday morning. All of this will slowly taper off
and end later Friday with warm advection bringing lowering inversion

A warming trend will then begin by Saturday as the flow becomes
zonal across the United States, with warm advection spreading east
across the Ohio Valley and Great Lakes. High temperatures will reach
the mid 30s by Friday afternoon, and then the low to mid 40s by
Saturday afternoon. Friday night and Saturday should be mainly dry
for the bulk of the region, with a weak stalled frontal boundary
just north of Lake Ontario.


January thaw, round 2, continues for the start of next week,
followed by cooler, but seasonable, temperatures returning for mid
to late week.

Fairly zonal, pacific influenced flow will be in place across the
CONUS on Sunday, as a trough exits from the Four Corners region. The
increasing southwesterly flow and rising heights aloft across the
forecast area ahead of the approaching trough will usher in warmer
temperatures from Sunday into Monday. High temperatures will run in
the 40s, both days, with perhaps a few locations near the 50 degree
mark by Monday. Expect to see showers develop in the vicinity of the
warm front across the region on Sunday along with ample cloud cover,
although it will not likely be a washout with plenty of dry time.
South of Lake Ontario, this would mainly be rain, with a mix of
either rain, freezing rain or snow for eastern Lake Ontario. An
approaching cold front Monday, tied to the ejecting trough moving
from the central plains to the eastern Great Lakes, will usher in
widespread, soaking rain showers. There will be ample moisture to
work with as the trough taps into a rich subtropical moisture source
from the Gulf of Mexico. Cooler air will rush back into the region
with blustery southwest to west winds behind the cold front passage,
bringing a return to more seasonable temperatures for mid-week.


For the 18Z TAFS mainly MVFR/VFR flight conditions are found. A cold
front is edging its way across the region this afternoon, and a wave
along this front will bring snow back into our region from the
south...with IFR conditions most likely across KJHW/KROC...and
possibly as far west as KBUF/KIAG. This system will pass through
tonight and tomorrow morning. Light synoptic flow will continue
light winds across the region through this TAF cycle. These winds
will increase some from the west tomorrow afternoon as cold air
advects into the region.


Wednesday night through Friday...localized MVFR to IFR
possible in scattered to occasionally more numerous lake effect snow
showers east of the lakes...with mainly VFR conditions elsewhere.

Saturday...Mainly VFR.

Sunday...MVFR with a chance of light rain (mixing with snow east of
Lake Ontario).


Winds will remain light across the region through tonight as a weak
area of low pressure passes near Lake Ontario, and eventually a
coastal low advances northward along the eastern coastline. Much
cooler air behind an upper level trough axis will filter across the
Eastern Great Lakes tomorrow afternoon and through much of the
remainder of the week. This will bring an extended period of small
craft conditions that will eventually end Saturday after a
period of strong southerly winds.


MARINE...Small Craft Advisory from 7 AM Wednesday to 10 PM EST Saturday
         for LEZ040-041.
         Small Craft Advisory from 1 PM Wednesday to 4 AM EST
         Sunday for LOZ042>044.



MARINE...THOMAS is the U.S. government's official web portal to all federal, state and local government web resources and services.