403
FXUS61 KBUF 180241
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
941 PM EST Wed Dec 17 2025

.SYNOPSIS...
A milder pattern through Thursday night as a southerly flow, at
times with strong winds. Temperatures will rise into the 40s
and lower 50s Thursday 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 starting Thursday afternoon, with strong southerly
winds remaining elsewhere, then becoming westerly Friday behind
a strong cold front.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
A surface ridge of high pressure will slide to our east tonight.
This surface high will still influence our region this evening, with
winds now lightly from the south, and allowing for temperatures to
dip below the freezing mark.

Later tonight as the surface ridge slides to the east the influences
of a strong western Great Lakes region strong storm system will
begin to take hold of our region. An increasing pressure gradient
will begin to strengthen the southerly flow such that air
temperatures, especially in the west will begin to slowly rise the
later half of the night.

These surface temperatures will continue to increase Thursday with
downslope southerly flow and dry conditions prevailing, allowing for
40s area-wide, and perhaps lower 50s for the Lake Plain, Genesee
Valley and the SLV. Models have trended slower with the arrival of
precipitation with the main upper level shortwave trough lingering
well to our west over the western Great Lakes.

For Thursday a LLJ of 50 knots will further increase to 70 knots by
the evening hours (especially near the I-81 corridor). This will
allow for south-southeast terrain force flow to downslope off the
Chautauqua Ridge, and Tug Hill with favorable areas late Thursday
afternoon and overnight gusting to 60 mph or greater. Have upgraded
the high wind watches to warnings, while beginning a wind advisory
for remaining areas for southerly winds gusting towards 50 mph. This
flow is not the prevailing flow direction for our region, with tree
and tree limbs more susceptible to falling.

The airmass will remain warm through midnight, with gusty southerly
winds continuing. Though prime conditions for snowpack ablation and
snowpack ripening, rainfall amounts up to a half an inch for WNY,
and an inch for Eastern Lake Ontario region will not be enough for
any flooding concerns. Rain showers will move into WNY late
afternoon/early evening and propagate eastward across the region.
Elevated instability is meager, with perhaps 50 J/KG of MUCAPE, so
will not include thunder within the forecast, though a rumble of
thunder along a strong cold frontal passage is possible.

The cold front will make its way across our region the second half
of Thursday night, with strong southerly winds veering to westerly.
Thermal profiles remain warm for much of our region allowing for a
continuation of plain rain showers, though cold air advection late
may begin the transition to snow on the hilltops of WNY the final
few hours of tonight.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Colder air behind a deep, but progressive surface low will see 850mb
temps drop 15-20 degC since early Friday morning throughout the day.
This will lead to a transition of precipitation from rain to snow
through the morning for western NY and around midday for north-
central NY as well as a continuation of strong winds across the
region before high pressure moves overhead Saturday providing a
short break to the active weather.

Strong Winds Continue Through Friday Evening: After the departure of
the strong southerly jet across the warm sector of this late week
system, a 45-50 kt 850mb westerly jet will extend across western NY
starting late Friday morning for the second phase of this wind event
with the upper trough axis passage. Despite being weaker than ~12-18
hours earlier, these winds aloft will still be around the
climatological 90th percentile for mid-December. CAA in the low-
levels will support momentum transfer of these stronger winds toward
the surface which is why the Wind Advisory from Thursday night will
extend through the early evening.

Lake Effect Snow Expected Friday and Friday Night: While morning
precipitation may still be in the liquid variety, expect a quick
transition over to snowfall with the arrival of colder air. Lake-air
temperature differences will be sufficient for lake effect snowfall
development and steep low-level lapse rates will see lake induced
ELs rise toward 7-8 kft through the afternoon (off Lake Erie) and
early evening (off Lake Ontario). Winds will primarily be westerly,
focusing the heaviest lake effect across southern Erie Co, western
Wyoming Co, northern Cattaraugus Co, and Chautauqua Co off Lake Erie
and into the Tug Hill off Lake Ontario. Inversion heights will
gradually fall through the overnight period with high pressure and
drier air aloft sliding overhead for Saturday. This moderate
snowfall Friday afternoon along with gusty winds that would further
reduce visibility with blowing snow could warrant the need to a
Winter Weather Advisory for Friday and Friday night downwind of the
lakes. Will continue to let the subsequent shifts monitor latest
forecast trends.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The high pressure ridge extending northward from the Mid-Atlantic
will be ushered out by a progressive upper level trough traversing
eastward along the US/Canadian border. Southerly flow on the
backside of the ridge will aid temperatures aloft warming ahead of
this front with 850mb temps hovering around 0 degC. This will lead
to precipitation likely falling as rain or wet snow before colder
air arrives early Sunday morning behind a surface cold front. This
frontal passage through western NY Saturday night/early Sunday
morning will also bring gusty winds 25-35 mph. Synoptic moisture
will be limited immediately behind the cold front with a narrow dry
slot shown in deterministic guidance lasting through Sunday morning.
Low-level moisture will return along a secondary trough passage
Sunday afternoon and transition to west-northwest flow focusing any
lake effect east of Lakes Erie and Ontario. Latest cluster analysis
shows subpar 850mb RH with no recovery along a secondary trough
Sunday night in a scenario made up of ~25% of the grand ensemble.
The majority of this cluster is made up of EC members, but brings
uncertainty to potential snowfall amounts despite brief periods of
moderate snowfall being possible for the western Southern Tier and
Tug Hill region Sunday afternoon and early evening.

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
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 /02Z THURSDAY THROUGH MONDAY/...
Some lingering MVFR ceilings at the start of the 00Z TAF period will
improve to VFR by late evening for the favorable downslope regions
on a light southerly flow. MVFR ceilings will likely hold for the
Southern Tier, including KJHW.

A strong LLJ will develop late tonight and through the remainder of
the TAF cycle. Before surface wind gusts increase, LLWS will be
included for the western 4 TAF sites late tonight and Thursday
morning.

It will remain dry through the daylight hours of Thursday as
precipitation with a cold front lingers just to our west. Surface
winds from the south Thursday afternoon, likely gusting to 30 to 35
knots which will begin to negate the effects of the still strong LLJ
aloft.

Outlook...

Thursday night...Deterioration to MVFR/IFR with rain developing from
west to east. Strong wind gusts, especially in downslope areas.

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 late tonight and
through the day Thursday.

Further increase in southerly flow to gale force is expected over
the lower Great Lakes by Thursday evening, and become even
stronger Friday behind a cold front. Gales to potentially 45
knots on the eastern half of Lake Ontario Friday. A gale watch
has been issued for both Lake Erie and Lake Ontario.

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 Thursday to 1 AM EST Saturday for
     NYZ001>006-010>014-020-021-085.
     High Wind Warning from 7 PM Thursday to 1 AM EST Saturday for
     NYZ007-008.
     High Wind Warning from 3 PM Thursday to 1 AM EST Saturday for
     NYZ019.
MARINE...Gale Watch from Thursday evening through Friday evening for
         LEZ040-041.
         Gale Watch from Thursday evening through late Friday
         night for LOZ042>045-062>065.
         Small Craft Advisory until 10 PM EST Thursday for
         LOZ043>045.

&&

$$

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