979
FXUS61 KBUF 180709
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
209 AM EST Thu Dec 18 2025

.SYNOPSIS...
A milder pattern will continue across western and north central NY.
Temperatures will rise into the 40s and lower 50s today as the
southerly winds take hold. These southerly winds will become very
strong along the north- northwesterly downslope regions of the
Chautauqua Ridge and Tug Hill region this afternoon through this
evening, with strong southerly winds remaining elsewhere. A strong
cold front will rush through the region late tonight, and strong
winds will become westerly Friday through Friday night.

&&

.NEAR TERM /THROUGH FRIDAY/...
A deep trough will move across the Plains today. The trough will
become negatively tilted across the Great Lakes region tonight
before moving across the Northeast Friday. A 984mb low centered over
northern Minnesota this morning will move across the Upper Great
Lakes today, then move northeast into Ontario and Quebec Provinces
tonight. An expansive pressure gradient with this system will lead
to strong winds for the eastern Great Lakes region through the end
of the work week.

A south wind will increase across the region today. Mild weather is
expected with temperatures reaching the mid to upper 40s, low 50s
under partly sunny skies. Southwest winds between 925-850mb will
increase to 40-50 knots today, reaching 70 knots tonight. A south-
southeast wind at the surface and strong low-level inversion will
support downsloping off the Chautauqua Ridge and Tug Hill Plateau
this afternoon through tonight. Wind gusts up to 60 mph are expected
along these regions in Chautauqua, Jefferson, and Lewis counties and
High Wind Warning is in effect. Elsewhere, wind gusts 45 to 50 mph
are expected this afternoon through tonight and a wind advisory
remains in effect.

A cold front will march towards the region through this evening.
Increasing moisture and lift will support rain spreading across the
region from southwest to northeast tonight. Temperatures will remain
in the 40s to low 50s for most of the night. Rainfall amounts of
0.25-0.5" are expected across the region, with 0.1"-0.25" from the
Lower Genesee Valley to the Finger Lakes region. The combination of
warm weather and rainfall will severely shrink the snowpack across
the region. There is a low risk of flooding. Wind gusts may taper
off some as rain moves into the region. The cold front will move
from west to east across the forecast area from late tonight through
mid-morning Friday. The core of the highest low-level winds will be
east of the cold front, however 40kts will linger behind the frontal
passage. Hi-res guidance is depicting a convective-looking line of
showers along the front. While instability is very low, the
steepening of lapse rates and sharp wind shift may support a rumble
of thunder. Gusty, westerly winds to 50 mph are possible behind the
front. Cold air advection will cause surface temperatures to fall
through the day. Anafrontal rain will transition to snow, first
across the higher elevations of western NY late tonight, then across
the remainder of the region through Friday morning.

Cold air will deepen across the region Friday. Steep lapse rates
will promote effective mixing and wind gusts of 40-50 mph will
continue through the day. Wind headlines will continue, however the
high wind warning will likely transition to a wind advisory Friday.
Widespread snow will taper off from west to east Friday morning,
with a transition to lake effect east of the Lakes by Friday
afternoon. A few inches of snow are possible across the higher
terrain east of the Lakes, with 2 to 4" possible along the
Chautauqua Ridge. As the snow character transitions to dry snow
Friday afternoon, some blowing snow is possible.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
The departed deepening sfc low will quickly track northeast from
central Quebec into the Canadian maritimes. A 50-60 knot jet aloft
will still reside across much of the region Friday night. It is
anticipated that strong gusty sfc winds of 45-50 mph will continue
into Friday evening within the fully mixed CAA regime.

In addition to the gusty winds...some measure of accumulating lake
effect snows will be found east of both Lakes. That is, atleast
through the first part of the night before equilibrium levels
rapidly fall and drier air pours into the region.

Off Lake Erie...

Winds will veer from WSW to W very early Friday evening which will
focus the heaviest lake snows across far southern Erie Co (from the
Boston Hill, south of Hamburg and East Aurora), western Wyoming Co,
and then Chautauqua Co, and northwest Cattaraugus Co. Not expecting
significant amounts but early estimates of 2-4" will be possible,
and in the most persistent snows 3-6", especially across the
Chautauqua ridge.

Off Lake Ontario...

Similar to Lake Erie but will have the longer fetch within a WSW to
W flow which will direct lake snows across southern Jefferson Co,
northern Oswego Co. and western Lewis Co. early Friday evening. As
winds veer a bit more and become W-WNW Friday evening lakes snows
will drift south over central Oswego but will also begin to weaken.
Overall...snowfall accumulations do `not` appear all that impressive
at this point, with early estimates of 4-7" in the most persistent
snows.

One last thing to mention...given that winds will be gusty Friday
evening blowing snow might become an issue. As was mentioned...will
possibly need headlines for the snowfall and potential blowing snow.
Lake snows will quickly weaken as we move into the overnight hours
off both lakes. This will take place as inversion heights fall and
drier air erodes synoptic moisture with high pressure building east
into the Lower Lakes.

High pressure passes to our south through the Mid-Alantic region
Saturday which should largely provide quiet dry weather. Any
lingering lake snows or flurries at this point will all but end by
Saturday morning. As the high passes by we will also see a
modification of the airmass with warming temps as southerly flow
developing across the region. Highs on Saturday will climb into the
30s, to even near 40F after a cold start (lows in the teens and 20s)
to the day.

Our attention then turns to a low pressure system passing by to the
north of the upper Great Lakes Saturday night. As the low continues
to head east it will send its trailing cold front through the Lower
Lakes overnight. With the front...we will see gusty winds (35-45
mph) and some measure of rain-snow showers which transitions to all
snow as cold air begins to spill into the region. On Sunday...a
secondary front plows through the area bringing with it an even
colder shot of air (H850 -14C/-15C) but a fairly dry airmass. In
terms of lake effect, latest model guidance isn`t all that bullish,
that is unless you look at the Canadian-NH which shows an upstream
components for both lakes Sunday afternoon-night. For now...have low
confidence at this stage and will just keep an eye on this lake snow
potential.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
Lake effect snow will linger into Monday morning as inversion
heights continue to gradually fall as surface high pressure slides
overhead.

Forecast uncertainty begins to increase headed into the
middle of next week with multiple different solutions from
deterministic/ensemble guidance on the next system passing in the
zonal flow. Generally, height rises across the central CONUS could
support relatively warmer temperatures to close out this overall
cold December.

However, latest NBM show MaxTs with large Interquartile Ranges (Most
Likely Range) from the freezing mark up into the mid-40s across
western NY.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A mix of flight conditions exist across western and north-central NY
this morning. Low stratus is across portions of western and north-
central NY, while valley fog has developed across the western
Southern Tier early this morning. MVFR/IFR conditions are possible
within these features early this morning. Surface high pressure will
continue to move east and a southerly wind will increase across the
region today. Fog and stratus will be short-lived this morning.

A storm system near the Upper Great Lakes region spans a large
portion of the lower 48 today. A strong low-level jet will move
across the region through tonight. The strongest winds will stay
above a surface inversion, however this will create low level wind
shear through tonight. Rain will move into the region this evening
and VFR flight conditions will become MVFR/IFR tonight. A strong
cold front will move across the region late tonight. Winds will veer
westerly with strong, gusty winds continuing through Friday.

Outlook...

Friday...Rain changing to snow showers from west to east early.
MVFR/IFR improving to VFR/MVFR in most areas, with lake effect snow
showers bringing local IFR east of the lakes. Very windy.

Saturday and Sunday...MVFR/VFR in scattered light snow showers.

Monday...VFR.

&&

.MARINE...
A dynamic system will pass across the eastern Great Lakes region
through Friday. Southerly will increase across the waters through
the first half of tonight.

South winds are expected to increase to gale force tonight. A cold
front will move across the Lakes late tonight, and winds will veer
out of the west. Gale force winds will become stronger Friday. Gales
to 45 knots on the eastern half of Lake Ontario Friday. A gale
warning has been issued for both Lake Erie and Lake Ontario
Friday.

West to northwest winds will slowly diminish Friday night, but small
craft conditions are expected the better part of the weekend and
into Monday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Wind Advisory from 3 PM this afternoon to 1 AM EST Saturday
     for NYZ001>006-010>014-020-021-085.
     High Wind Warning from 7 PM this evening to 1 AM EST Saturday
     for NYZ007-008.
     High Wind Warning from 3 PM this afternoon to 1 AM EST
     Saturday for NYZ019.
MARINE...Small Craft Advisory from 7 AM this morning to midnight EST
         Friday night for LEZ020.
         Small Craft Advisory from 7 AM this morning to 7 AM EST
         Friday for LEZ040-041.
         Gale Warning from 7 AM Friday to midnight EST Friday night
         for LEZ040-041.
         Small Craft Advisory from 7 AM this morning to 7 AM
         EST Friday for LOZ043>045.
         Small Craft Advisory from 10 AM this morning to 7 AM EST
         Friday for LOZ042.
         Gale Warning from 7 AM Friday to 3 AM EST Saturday for
         LOZ042>045-062>065.

&&

$$

SYNOPSIS...HSK/Thomas
NEAR TERM...HSK
SHORT TERM...AR
LONG TERM...AR/Brothers
AVIATION...HSK
MARINE...HSK/Thomas/TMA