Forecast Discussion

134
FXUS61 KBUF 181908
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
208 PM 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 NIGHT/...
A deep 986mb surface low moving towards Lake Superior will
continue to track eastward north of the Canadian border through
the rest of today into tonight. Latest NAEFS progs this surface
low tracking across Ontario to be near climatological minimum
for mid-December. Resultant wind fields from sharp mslp/height
gradients will lead to 2 periods of strong winds across western
NY. First, strong southerly flow late this afternoon and
overnight before the arrival of strong westerly flow midday
Friday behind the morning`s cold frontal passage. In addition to
the winds, widespread precipitation is expected starting
tonight and continue into Friday. Ptype will be rainfall ahead
of the cold front before transitioning to snowfall Friday
morning across western NY and around midday for north-central
NY. Eventually, this systems precipitation shield will give way
to lake effect snow development off Lakes Erie and Ontario for
Friday afternoon and evening.

Strong Winds Expected Tonight and Friday across WNY:
Surface winds will continue to rise steadily this afternoon
across western NY with the approaching system from the west.
Latest NAEFS guidance shows by 06z a widespread 60+ kt southerly
jet at 850mb spreading overhead, above the climatological 99th
percentile for mid- December. These strong winds across the
system`s warm sector along with ridgetop inversions supportive
of forced flow will lead to wind gusts 35-50 mph across much of
the area overnight. Areas north of the Tug Hill Plateau and the
Chautauqua Ridge could see gusts up to 60mph before the arrival
of more widespread precipitation cooling the column and
weakening those low level inversions. High Wind Warnings remain
in effect for Lewis and Jefferson Co in north- central NY, and
Chautauqua Co in western NY. While gusty winds may accompany the
frontal passage Friday morning, the second round of stronger
flow aloft will overspread much of western NY Friday afternoon.
The past few runs of the GFS have shown a strengthening 850mb
westerly jet around 50+ kt that, with CAA behind the front, will
aid in momentum transfer to the surface. However, this does sit
on the higher end of the GEFS distribution for 850mb winds
Friday afternoon. These stronger winds will remain into Friday
evening before starting to diminish with the system
progressively moving east.

Widespread Rainfall Tonight and Early Friday Transitioning to Lake
Effect Snow by Friday Afternoon:
Scattered rain showers this evening will become more widespread
early Friday morning. Hi-Res guidance continues to suggest a
stronger line of storms along the frontal boundary near daybreak
for western NY, but this will be mainly frontally forced.
Liquid precipitation of 0.25-0.50" will be enough to help
further reduce the present snowpack and possibly swell area
creeks and streams, but the chance for flooding remains low at
this time. Immediately behind the front, the column will begin
to cool as ptype transitions over to wet snow. However, the
cooler airmass will be locked behind a secondary boundary
passing through later Friday morning that will see 850mb temps
drop closer to -10 to -14 degC by the afternoon and unlocking
the lake effect potential. While initially bands may set up
northeast of the lakes, they should quickly focus east of the
lakes with the stronger westerly flow and lake induced ELs
reaching 6-8 kft. Flow will continue to veer out of the
northwest and inversion height will gradually lower throughout
the overnight period with high pressure approaching from the
west. Despite being short-lived, should still see notable
snowfall rates exceeding 1"/hr in the most persistent bands. A
combination of that along with strong winds leading to blowing
snow and further reduced visibility has prompted the issuance of
Winter Weather Advisories starting mid- morning Friday off Lake
Erie and early afternoon off Lake Ontario through Friday night.


&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
High pressure will ridge north as it slides east across the Mid
Atlantic states with winds backing to the southwest then south
through the day. This will quickly shut down any lingering lake
effect east and southeast of the lakes Saturday morning as a warmer
and drier air mass moves into the area, allowing for a mainly dry
start to the weekend along with temperatures rebounding back to a
few degrees above average after a chilly start to the day. Will
become quite breezy from the south-southwest during the afternoon
ahead of an approaching cold front.

Quiet weather doesn`t last long as this first of two cold fronts
crosses the region Saturday evening with a few rain and higher
elevation wet snow showers and breezy conditions. Upslope areas east
of the lakes may see some light accumulations by Sunday morning.
Secondary cold front slides east across the area Sunday morning
ushering in another shot of chilly air with 850mb temps falling into
the minus mid teens C for Sunday and Sunday. Better moisture
associated with approaching mid level trough and fresh batch of cold
air aloft will help ignite some lake snows Sunday and Sunday night,
especially east then southeast of Lake Ontario. While no big snows
are expected during this timeframe, a few to several inches will be
possible east and east-southeast of Lake Ontario, with the highest
amounts over the Tug Hill. Expect gusty west winds through the day
Sunday, tapering down later Sunday night as stronger winds off the
deck pull east and surface high pressure approaching from the west
relaxes the pressure gradient. Expect below average highs and lows
for Sunday and Sunday night respectively.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Some discrepancies have crept into the lake effect potential to
start the work week, lowering the overall confidence in LES shutting
down Monday, at least completely. Medium range guidance is trying to
shift an area of high pressure a bit further south of the area,
which would allow a cold west to west-northwest flow to linger into
at least a portion of Monday, with some LE snow showers potentially
lingering east of the lakes (mainly Lake Ontario) into Monday. High
pressure will eventually win out, bringing a brief period of mainly
dry weather with warmer air moving in aloft, before the next system
in the pipeline brings the likelihood for snow or a wintry mix
changing to rain for Tuesday as an attendant warm front crosses the
region.

A few rain or wet snow showers may linger into Tuesday night, before
high pressure tries to dry things out mid week. A warm front
associated with a system moving by to our northwest may then bring
the chance of some rain and snow showers Christmas Eve night,
transitioning to mainly rain showers from west to east on Christmas
Day as warmer air works in. This is still seven days out and there
is cold air lingering across Canada. Atmosphere is a fluid, so
things can still fluctuate. Stay tuned.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR conditions currently across area terminals with gusty southerly
winds this afternoon and passing SCT mid-to-upper level clouds.
Southerly winds will continue to increase late this afternoon into
tonight with gusts 30-40 kt likely for most terminals. Scattered
rain showers will move into western NY tonight, becoming more
widespread early Friday morning. IFR conditions look likely Friday
morning with reduced visibilities along a stronger line of showers
along a cold front moving west to east across the region. Low
ceilings will remain behind the front Friday morning with
precipitation changing over to snowfall around mid-morning. KART
will see this precipitation change over closer to midday. By Friday
afternoon, snowfall will become more localized in lake effect bands
east of the lakes. Additionally, strong winds are expected again
for area terminals, but will be out of the west Friday afternoon.

Outlook...

Friday Night...Wind conditions continuing through the early evening
with lake effect snow showers bringing local IFR east of the lakes.

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

Monday...VFR.

Tuesday...MVFR/VFR with scattered showers.

&&

.MARINE...
A dynamic system will pass across the eastern Great Lakes region
through Friday. South winds are expected to increase to gale
force by Friday morning. A cold front will move across the
Lakes late tonight, and winds will veer out of the west. Gales
to 45 knots are expected on the eastern half of Lake Ontario and
up to 40 knots on the eastern end of Lake Erie 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 until 1 AM EST Saturday for NYZ001>006-010>014-
     020-021-085.
     Winter Weather Advisory from 1 PM Friday to 7 AM EST Saturday
     for NYZ006>008.
     High Wind Warning from 7 PM this evening to 1 AM EST Saturday
     for NYZ007-008.
     Winter Weather Advisory from 10 AM Friday to 1 AM EST Saturday
     for NYZ012-019-020-085.
     High Wind Warning until 1 AM EST Saturday for NYZ019.
MARINE...Small Craft Advisory until midnight EST Friday night for
         LEZ020.
         Small Craft Advisory until 7 AM EST Friday for LEZ040-041.
         Gale Warning from 7 AM Friday to midnight EST Friday night
         for LEZ040-041.
         Small Craft Advisory until 7 AM EST Friday for
         LOZ042>045.
         Gale Warning from 7 AM Friday to 3 AM EST Saturday for
         LOZ042>045-062>065.

&&

$$

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

NWS BUF Office Area Forecast Discussion