985
FXUS61 KBUF 212321
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
721 PM EDT Mon Sep 21 2026

.WHAT HAS CHANGED...
Only minor changes with this forecast update.

&&

.KEY MESSAGES...
1) Below normal temperatures and mainly dry weather will continue
through the upcoming week, with a few showers possible across the
Southern Tier at times.

&&

.DISCUSSION...
KEY MESSAGE 1...Below normal temperatures and mainly dry weather
will continue through the upcoming week, with a few showers possible
across the Southern Tier at times.

An upper level trough and closed low will slowly move east across
the Midwest to Ohio Valley through mid-week. High pressure will
remain across eastern Canada, bringing continued northeast flow
across the eastern Great Lakes region though a majority of the work
week.

A shortwave trough will move across the Ohio Valley this evening.
Subsidence and dry air will maintain mostly dry weather across the
region, however isentropic lift and deep moisture will approach the
NY/PA line. Widely scattered showers are possible across the western
Southern Tier through tonight, mainly near the PA state line.
Otherwise, a dense shield of cirrus will continue across the eastern
Great Lakes through much of the night, with some partial clearing
possible towards daybreak. Low temperatures will fall to the 40s
with locations across the North Country possibly seeing the upper
30s. Confidence in temperatures reaching the upper 30s is low, as
the position of the high well to the north and uncertainty in cloud
cover does not offer the best set-up for radiational cooling. With
that being said, there is a non-zero chance of patchy frost in known
cold spots across Jefferson and Lewis counties tonight.

Low-level easterly flow will increase to our south ahead of the
approaching closed low Tuesday. A few showers along the NY/PA border
can`t be ruled out. An upper level ridge is expected to move south
from eastern Canada for the end of the work week, and widespread dry
weather is anticipated across the forecast area. Temperatures will
gradually increase each day but stay below normal for late
September.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Strong high pressure will remain in place across Ontario and Quebec
tonight through Tuesday, keeping the majority of the deeper
moisture, rain chances, and lower CIGS south of the area. A dense
shield of cirrus will continue to stream northeast across the
eastern Great Lakes tonight, with VFR prevailing. A few sprinkles or
light showers may clip areas along the NY/PA line, otherwise dry
weather will prevail for the rest of the area. Some lake effect
clouds may develop overnight in ENE flow across the Niagara
Frontier, with patchy MVFR CIGS possible. The most likely TAF
location to experience MVFR CIGS in lake effect clouds is KIAG, with
a lower chance at KBUF and KROC given the expected ENE flow
direction.

Tuesday, low level moisture over PA will spread a little farther
north into the Southern Tier, with areas of MVFR CIGS developing
across the higher terrain. Otherwise, VFR will continue to prevail
for the rest of the area with cirrus level clouds and scattered
diurnal cumulus.

Outlook...

Tuesday night through Saturday...Mainly dry weather with
predominantly VFR flight conditions expected through the period. The
exception will be river/lake valley fog and local IFR potential on
any given night where winds become light, and skies become clear to
partly cloudy late night into the hours surrounding daybreak.

&&

.MARINE...
Expansive surface high pressure over Ontario Province will build
across Quebec and strengthen through midweek...while weak surface
troughing slides eastward across the Ohio Valley and mid-Atlantic
states. The resulting pressure gradient will maintain a moderate to
fairly brisk flow across the Lower Great Lakes through midweek that
will also gradually veer from northeasterly to easterly over time.

This will allow for SCA-level conditions across the nearshore waters
of both lakes with the exception of Mexico Bay to the Saint Lawrence
River. SCAs will become more confined to areas from Hamlin Beach to
the Niagara River by Wednesday as the flow veers more easterly. Any
lingering SCA-level conditions should then subside Wednesday night
as the surface ridge builds further southward and results in a
weakening of the pressure gradient across our region...along with a
commensurate lowering of winds and wave action.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement through Wednesday evening for NYZ001-
     002.
     Beach Hazards Statement through Wednesday morning for NYZ003-
     004.
MARINE...Small Craft Advisory until 11 PM EDT Tuesday for LEZ040-041.
         Small Craft Advisory until 8 PM EDT this evening for
         LOZ030.
         Small Craft Advisory until 8 PM EDT Wednesday for LOZ042.
         Small Craft Advisory until 8 AM EDT Wednesday for LOZ043-
         044.

&&

$$

DISCUSSION...Hitchcock/HSK
AVIATION...Hitchcock
MARINE...HSK/JJR