743
FXUS61 KBUF 070702
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
202 AM EST Fri Nov 7 2025

.SYNOPSIS...
Low pressure will track from the Upper Great Lakes to south-central
Quebec through tonight...and in the process will pivot its trailing
cold front across our region tonight. The front will be preceded by
another round of showers and gusty winds today...with a few leftover
showers then lingering into Saturday morning east of the lakes...
with an otherwise dry day expected Saturday. Another low pressure
system pushing northeast from the Ohio Valley will then bring a
return to more unsettled weather later Saturday night and Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
During the course of today gradually deepening low pressure will
make its way from Lake Superior to a position a bit northeast of
Georgian Bay...while pivoting its trailing cold front eastward to
southern Ontario/central Lake Erie. DCVA/height falls and the
strengthening warm air advection pattern/attendant 50-60 knot low
level jet out ahead of the front will push a round of fairly
widespread showers across the region this afternoon and early this
evening. Basin average rainfall amounts from these currently look to
range from 0.25-0.50" east of the lakes (perhaps a bit higher across
the Tug Hill) to one or two tenths of an inch elsewhere.

At the same time...the low level jet will provide us with another
round of gusty south to south-southwesterly winds...with these
peaking prior to the arrival of the showers...then dropping off from
west to east through the rest of the day and early evening owing to
the stabilizing effects of the rain and the eastward progression of
the swath of stronger winds aloft. While the strongest winds will be
prevented from fully mixing down to the surface by the warm air
advection pattern...mechanical mixing and downsloping effects will
still help to at least partially bring some of these down to the
surface. This will particularly be the case in the typically favored
areas along the Lake Erie shoreline and across the higher terrain
where gusts to 40-45 mph will be possible...with gusts of 30-35 mph
expected elsewhere. Again...these will be strongest out ahead of the
main swath of showers...with lowering winds and gusts then expected
from west to east through the rest of the day and early evening
hours. Otherwise...the warm advection pattern will result in a
milder day today with highs mostly rebounding into the 50s...and
perhaps to around 60 in the vicinity of Dunkirk and Dansville.

With strong dry slotting aloft overspreading the region late today
and this evening...shower coverage attendant to tonight`s cold
frontal passage will actually be considerably less than during the
day...with mainly scattered activity perhaps becoming briefly more
numerous across the higher terrain east of the lakes as the low
level flow veers more westerly and upsloping increases. Behind the
front...some limited upslope and lake enhanced rain showers will
then linger east of the lakes overnight...with dry weather expected
elsewhere. Lows will mainly be in the lower half of the 40s...with
perhaps a few upper 30s across the interior of the Southern Tier and
North Country.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Surface low pressure over initially over south-central Quebec will
weaken as it slides eastward into the Gulf of St. Lawrence through
the day Saturday. In its wake, a progressive wedge of surface high
pressure will build north and east of the forecast area with decent
post-frontal CAA bringing 850mb temps down to between 0C and -6C.
While most areas will remain dry through the day, some minor lake
effect rain showers will linger southeast of the lakes with broader
cloud coverage. Daytime temperatures will likely remain in the 40s
as they struggle to warm with the colder temps and clouds aloft.

The mainly dry weather will be short lived as a deep mid/upper level
closed low drifting south across northern Ontario begins to interact
with a shortwave trough racing east across the northern Ohio Valley
Saturday night. As the latter moves across Indiana it will begin to
take a northeastward turn, which will direct an organizing area of
sfc low pressure directly towards the CWA. An area of more
stratiform precip associated with the system`s warm front will push
into WNY late Saturday night before spreading to the North Country
closer to daybreak Sunday morning. A few deterministic guidance
packages and respective ensemble members continue to advertise a low
track just south of the CWA border with a period of wintry mix
across WNY. While not completely out of the question, NBM 4.3/5.0
probabilities of mixed p-types have been consistent in indicating
that this as the more unlikely scenario. Greater chances for wet
snow will be found across the North Country where some minor
accumulations will be possible in the morning before changing over
to plan rain.

Following a period of widespread rain showers Sunday, a much colder
airmass within the aforementioned closed low will be advected in
across the eastern Great Lakes behind a cold front. With 850mb temps
plunging down to around -8C by early Monday morning, any wrap around
showers will change over to snow through Sunday night. While the
lower elevations could very well see their first snowfall of the
season during this timeframe, any accumulations should be very minor
in most areas. A predominately north to northwest flow will allow
localized lake enhancement south to southeast of the lakes, where an
inch or two could fall by daybreak.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
An anomalously deep (500mb heights 2-4SD below normal) but
progressive longwave trough will translate across the CONUS east of
the Mississippi early next week, with the upper level trough axis
moving offshore Tuesday. 850mb temps subsequently bottoming out
around -10C across the eastern Great Lakes will set the stage for a
prolonged period of on and off lake effect precipitation across the
region.

The main focus this period continues to be Monday into Tuesday night
when temperatures will be cold enough at the sfc and aloft to
support accumulating snow. This stated, there still remains a fair
amount of uncertainty in the other details of how the pattern will
evolve including available synoptic moisture, steering flow
orientation/timing of wind shifts, and potential upstream
connections to Lake Huron and Georgian Bay. The prevailing consensus
from the long range guidance suggests that the period should be
dominated by northwest flow through Monday night, before increasing
and becoming westerly then southwesterly sometime later Tuesday.
Model thermal/moisture profiles suggest the most favorable
conditions for accumulating LES should occur sometime Monday night
into early Tuesday within the NW flow regime, which would direct the
greatest total accumulations through the period southeast of the
lakes...well south of the Buffalo and Watertown Metros, and away
from Rochester as well.

While it may become quite windy as the flow backs to the southwest
Tuesday, temps aloft should be warming quickly by this point. It
will likely still cool enough for continued enhancement from the
lakes, though p-type will likely start to mixing back to rain across
the lower terrain areas. This trend will continue through Wednesday,
with rain becoming the dominant p-type in most areas, though PoPs
remain elevated through Thursday as another potential wave of sfc
low pressure moves across the eastern Great Lakes.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Through about 09z/10z a few spotty/light lake effect rain and snow
showers and localized MVFR will be possible east of Lake Ontario...
with these then dissipating as the low level flow backs further to
southerly and becomes increasingly sheared. Otherwise...VFR
conditions under increasing/thickening high and mid level clouds
will prevail through sunrise.

Low pressure will then make its way from Lake Superior to just
northeast of Georgian Bay today...before moving on to south-central
Quebec tonight. This system will push its trailing cold front across
the area tonight...with a prefrontal swath of widespread showers
crossing the area this afternoon and early this evening...followed
by more scattered activity with the front itself tonight. In the
wake of the front...upsloping and lake enhancement will then
generate some limited lake effect rain showers east of the lakes
overnight. General VFR conditions at the start of the day will
deteriorate to MVFR across the lower elevations/IFR across the
higher terrain once the showers arrive and help to saturate the
lower levels...with general improvement to a mix of MVFR/VFR
then following the cold frontal passage tonight.

A passing 50-60 knot low level jet out ahead of the cold front will
also likely lead to a period of wind shear early this morning across
the higher terrain of the Southern Tier (including KJHW)...with
increasing partial mixing down of the stronger winds aloft then
leading to a period of 25-35 knot wind gusts out ahead of the main
round of showers. Once the showers arrive...winds and gusts will
gradually diminish from west to east through the balance of the day
and this evening owing to the stabilizing effects of the rainfall
and the continued steady eastward progression of the low level jet.

Outlook...

Saturday...VFR/MVFR with leftover showers east of the lakes in the
morning.

Sunday...Restrictions likely with widespread rain showers, mixing
with/changing to snow and diminishing in coverage Sunday night.

Monday and Tuesday...Lake effect snow showers downwind of the lakes
with localized IFR, otherwise scattered snow showers and VFR/MVFR.

&&

.MARINE...
Slowly deepening low pressure will make its way from Lake Superior
to just northeast of Georgian Bay today...before moving on to south-
central Quebec tonight. This will bring another round of 20-30 knot
southerly to southwesterly winds to both Lakes Erie and Ontario
today...with winds then veering northwesterly and diminshing from
west to east tonight and early Saturday following the passage of
this system`s trailing cold front. As such...Small Craft Advisories
remain in effect as outlined below.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 8 AM this morning to 4 AM EST
         Saturday for LEZ020.
         Small Craft Advisory until 7 AM EST Saturday for LEZ040-
         041.
         Small Craft Advisory from 8 AM this morning to 10 AM
         EST Saturday for LOZ042.
         Small Craft Advisory from 8 AM this morning to 3 PM EST
         Saturday for LOZ043>045.

&&

$$

SYNOPSIS...JJR
NEAR TERM...JJR
SHORT TERM...PP
LONG TERM...PP
AVIATION...Hitchcock/JJR
MARINE...JJR