876 
FXUS61 KBUF 122349
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
649 PM EST Fri Dec 12 2025

.SYNOPSIS...
Impactful lake snows off Lake Ontario will slowly lift north and 
then weaken in the process tonight. Lake effect snow will 
redevelop late tonight across Niagara County out ahead of a 
strong cold front...with the front then rapidly pushing the lake
snows back southward and bringing a few quick inches of snow to
areas northeast and east of Lakes Erie and Ontario during 
Saturday. Much colder air pouring across the region in the wake 
of the frontal passage will then help to generate locally heavy 
lake snows east and southeast of the lakes Saturday night 
through Sunday night.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
High pressure over the Upper Ohio Valley will slide east and 
offshore through Saturday morning...while rapidly giving way to 
a closed upper-level low and associated clipper system that will
track from Ontario to Quebec from later tonight through 
Saturday night. The clipper will sweep its trailing arctic cold 
front across our region between Saturday morning and early 
Saturday afternoon...with another shot of cold air (850 mb temps
falling into the -17 to -20C range) then pouring across our 
region during the remainder of Saturday and Saturday night. 

Digging further into the details on the lake snows...

Off Lake Erie...

Flow will back from the west to southwest which may re-invigorate a 
lake response northeast off Erie later this evening. Accumulations at 
this point will be minor if any at all. That said...things begin to 
change later tonight as the arctic cold front approaches and 
provides an increase in moisture and large-scale forcing...resulting 
in lake enhanced snows initially becoming better organized across 
Niagara County and extreme far northwestern Erie county (i.e. Grand 
Island and Tonawanda) by very late tonight...where a general 1-2 
inches will be possible by daybreak. 

The arctic cold front will then plow across the area Saturday 
morning...while rapidly pushing the lake enhanced snows southward 
across the Niagara Frontier/Buffalo Metro area and into the Southern 
Tier by midday as winds veer to westerly in its wake...with a brief 
burst of heavy snow and another 1-3" of quick accumulation possible 
during this time frame. A general westerly flow will then produce 
weaker multibanded lake snows across the higher terrain of the 
Chautauqua Ridge and Boston Hills later Saturday through Saturday 
night...where an additional 3-5" will be possible within the most 
persistent lake snows. Coupled with additional snowfall expected 
during the Short Term period (details on which follow below)...this 
will result in 48-hour snowfall totals through Sunday night of 
around a foot in the most persistent lake snows...and as such we 
have upgraded the Winter Storm Watch for Chautauqua/Cattaraugus/ 
Allegany counties to a Lake Effect Snow Warning. 

Off Lake Ontario... 

Wind flow backing to the west with a single stronger band becoming 
established over northern Oswego this evening...expect an additional 
2-4" inches of accumulation in the most persistent snows as the band 
moves north. 

Overnight the flow will continue to back to southwesterly and then south-
southwesterly while becoming increasingly sheared...sending rapidly 
weakening lake snows northward across the Watertown area to the 
Saint Lawrence River... with 1-3" expected from roughly Watertown 
southward and an inch or less further north to the Saint Lawrence 
River...with some weak lake effect snow showers then persisting near 
the Saint Lawrence River through daybreak. 

On Saturday the approach of the arctic front will allow the remnant 
lake snow showers to intensify into a band of lake enhanced snow 
over Canada in the morning...with the frontal passage then rapidly 
sweeping these southeast across the North Country to the vicinity of 
the Tug Hill during the late morning and afternoon hours. Additional 
accumulations through the day Saturday look to be on the order of 2-
3 inches. Much more significant lake snows will then develop 
Saturday night across the southern Jefferson/northern Oswego 
counties and the Tug Hill as a westerly flow of progressively colder 
air and deepening moisture results in an increasingly favorable over-
lake environment...with guidance continuing to depict a strong low-
level convergent band developing along the long axis of the lake. 
This should result in the development of an intense LES band capable 
of 2-3"/hour snowfall rates...with this then slowly settling south 
and deeper into Oswego county overnight as the low level flow 
continues to gradually veer out ahead of an approaching secondary 
arctic cold front. Lake Effect Snow Warnings correspondingly remain 
in effect for Oswego/Jefferson/Lewis counties to cover this round of 
lake effect...which will persist into the beginning of the Short 
Term period. More details on that follow below...

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Deep longwave troughing will be in place across the Great Lakes and 
Northeast for the later half of the weekend and the start of the new 
work week. A potent shortwave trough will be in the midst of diving 
across the eastern Great Lakes Sunday, supporting a plume of colder 
air to filter across the Great Lakes, keeping the ongoing lake 
effect ongoing east/southeast of the Lakes.

Brief ridging Sunday night will give way to a weaker mid-level 
shortwave trough diving across the Great Lakes Monday. Ongoing lake 
effect will become lake enhance and shift north as winds back from 
northwest to southwest. Additionally outside of the lake enhanced 
areas east of the lakes, expect a widespread light snowfall across 
the remainder of the area.

Looking further into the details...

Off Lake Erie - Northwest flow Sunday will support lake enhanced 
upslope snow across the higher terrain of the western Southern Tier. 
With in this there will likely be an upstream connection to Lake 
Huron that will locally enhance snowfall. Drier air, shear and 
surface high pressure will weaken lake snows Sunday night and 
Monday. However, activity won't completely diminish as the next mid-
level feature arrives to the eastern Great Lakes late Monday, 
reviving the activity and shifting it north as it becomes lake 
enhanced. By Monday afternoon and evening, the lake effect will lie 
northeast of the lake, impacting the Buffalo Metro. Similar thinking 
to the previous forecast warranting the Winter Storm Watch, long 
duration snowfall amounts has supported the upgrade from Watch to 
Lake Effect Snow Warning for Chautauqua, Cattaraugus, and southern 
Erie counties.

Off of Lake Ontario - Ongoing intense lake effect snow east of the 
lake will continue its trip southward towards the southern shoreline 
of the Lake Sunday with the area under northwest flow. Within this 
band, up to 2-3 inch per hour rates will be possible Sunday morning. 
A sharp wind shift associated with the passage of a secondary arctic 
front will move across the lake Sunday afternoon, transitioning the 
single band onshore and breaking the activity apart into a spray of 
weaker multibands and snow showers along the entire southern 
shoreline of the lakes. Lake effect and showers will expand 
southward across the Finger Lakes. Activity will continue Sunday 
night while gradually weakening. However, activity won't completely 
diminish as the next mid-level feature arrives to the eastern Great 
Lakes late Monday, reviving the activity and shifting it north as it 
becomes lake enhanced. This band will traverse as far north as the 
Watertown Metro Monday morning before shifting south and hanging 
overhead of the Tug Hill late Monday and Monday night.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Heading into the middle of the work week, mid-level flow will become 
more zonal, forcing cold air to retreat north into Canada and allow 
for warmer air to move into the Ohio Valley and Great Lakes. 
Temperatures will warm up into the upper 20s and low 30s Tuesday and 
solidly into the 40s by Thursday. Temperatures will then become 
cooler for the end of the week, however how cold it will be still 
remains questionable. Depending on the guidance, temperatures at 
850mb plunge back towards -2C to -20C depending on the model 
guidance.

Outside of the temperature trends, some relief in activity will 
arrive Tuesday with surface high pressure sliding east into the 
Atlantic. The next trough passage will arrive late Wednesday and 
pass across the eastern Great Lakes through Friday supporting the 
return of active weather. Initially with the warmer temperatures 
Wednesday and Thursday precipitation should fall as plain rain. 
Depending on how cold of an air mass arrives late in the week, will 
support rain to change back to snow.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR-MVFR conditions will grace most area terminals this evening, 
that don't see impacts from the lake snows.  

Backing of the low-level flow from west to south-southwesterly late 
this evening will result in the lake snows east of Lake Ontario 
weakening and lifting northward across the KART terminal to the 
Saint Lawrence River...with some IFR possible there for a few hours. 

Additionally...could also see some brief/localized MVFR/IFR at 
KBUF/KIAG for a few hours if lake snows redeveloping northeast of 
Lake Erie late this evening. 

Late tonight and early Saturday morning an approaching arctic cold 
front will result in lake enhanced snows strengthening north-
northeast of both lakes...with the cold frontal passage then rapidly 
shunting these southward across the KIAG/KBUF terminals during 
Saturday morning...and the KART terminal between later Saturday 
morning and early Saturday afternoon. These will probably bring a 
brief burst of moderate to heavy snow and IFR/LIFR to the above 
terminals while passing through...with the northeastern edge of 
these possibly also briefly clipping the KROC terminal with some 
brief IFR Saturday morning. In the wake of the front...weaker lake 
snows and associated IFR/LIFR will then set up east of the lakes 
Saturday afternoon. Outside of the lake enhanced/lake effect 
snows...conditions will be predominantly VFR/MVFR with just some 
scattered snow showers. 

Outlook...

Saturday night and Sunday...VFR/MVFR with scattered snow 
showers...and local IFR/LIFR in lake effect snow east of the lakes 
Saturday night/the start of Sunday shifting to areas southeast and 
south of the lakes.

Monday...VFR/MVFR with scattered snow showers. Local IFR in lake 
effect snow east and southeast of the lakes.

Tuesday...VFR/MVFR with a chance of snow showers east of Lake 
Ontario.

Wednesday...Mainly VFR.

&&

.MARINE...
Elevated southwesterly to westerly flow will be commonplace across 
the Lower Great Lakes for much of the time through at least early 
Monday...and for this reason Small Craft Advisories are in effect as 
outlined below.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Storm Watch from late Saturday night through Monday 
     morning for NYZ004-005.
     Lake Effect Snow Warning until 4 PM EST Sunday for NYZ006.
     Lake Effect Snow Warning from 1 PM Saturday to 1 PM EST Sunday 
     for NYZ007-008.
     Lake Effect Snow Warning from 7 AM Saturday to 7 AM EST Monday 
     for NYZ019-020-085.
MARINE...Small Craft Advisory from 4 AM to 7 PM EST Saturday for LEZ020.
         Small Craft Advisory from 10 PM this evening to 1 AM EST 
         Monday for LEZ040-041.
         Small Craft Advisory until 1 AM EST Monday for LOZ042.
         Small Craft Advisory until 7 AM EST Monday for LOZ043-044.
         Small Craft Advisory until 4 AM EST Monday for LOZ045.

&&

$$

SYNOPSIS...AR/JJR
NEAR TERM...AR/JJR
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...AR/JJR
MARINE...JJR