457
FXUS61 KBUF 131039
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
639 AM EDT Thu Aug 13 2026

.WHAT HAS CHANGED...
No major changes with this forecast update.

&&

.KEY MESSAGES...
1.) Mainly dry weather is expected through Saturday.

2.) The potential for scattered showers and thunderstorms
increases this Saturday night into Sunday.

&&

.DISCUSSION...
Key Message 1...Mainly dry weather is expected through Saturday.

Cyclonic NW`erly flow aloft and embedded shortwave disturbances
affect Western and Central NY today. At the surface, a weak
trough continues to impact our region. One trough axis
accompanying the aforementioned disturbances aloft will sweep
SE`ward across our CWA during the predawn hours of this morning,
while another will sweep SE`ward across eastern Lake Ontario
and North-Central NY this afternoon through early evening.
Isolated showers and thunderstorms are possible along and ahead
of these surface trough axes prior to sunrise this morning and
during this afternoon through early evening as low-level convergence
and moist ascent along the surface trough axes and downshear outflow
boundaries release primarily weak boundary layer CAPE amidst
moderate to strong deep-layer bulk shear. A lack of greater
instability should prevent storms from becoming severe. Early this
evening, any lingering convection in North-Central NY should
dissipate by sunset as the boundary layer stabilizes via nocturnal
cooling. Current odds favor fair weather in Western and Central NY
tonight through Saturday as a high pressure ridge at the surface and
aloft builds from the northern Great Plains and vicinity, and is
accompanied by stabilizing subsidence. However, a slight chance of a
few showers and thunderstorms exists in/near North-Central NY on
Friday, when another shortwave disturbance embedded in continued
NW`erly flow aloft may graze that portion of our CWA. However, there
is disagreement among various NWP models regarding the amplitude of
this shortwave trough and whether any associated showers/storms will
instead be focused to the north and east of our CWA.

Weather pattern evolution at the surface and aloft will result
in negligible air mass change through Saturday. Daily highs in
the 70`s to lower 80`s are expected today through Saturday.
Partly to mostly cloudy sky and weak surface winds should be
accompanied by lows mainly in the 50`s to lower 60`s around
daybreak this morning. Clearer sky and weak surface winds should
result in lows reaching mainly the upper 40`s to near 60F
around daybreak Friday and Saturday, respectively. The coolest
lows are expected in Lewis County, especially the Black River
Valley, where efficient radiational cooling should be complemented
by cool air drainage from adjacent higher terrain. Note:
sufficient radiational cooling and low-level moisture should
result in patchy radiation fog and localized steam fog in the
valleys of the Western Southern Tier, Finger Lakes, and Eastern
Lake Ontario Region during the predawn hours through shortly
after daybreak today through Saturday, respectively.

Key Message 2...The potential for scattered showers and thunderstorms
increases this Saturday night into Sunday.

During Saturday night through Sunday morning, the above-mentioned
ridge at the surface and aloft should exit E`ward and be followed
by W`erly flow aloft and embedded shortwave troughs, in addition
to the NE`ward passage of a surface warm front as a surface low
wobbles E`ward across the northern Great Lakes. The warm front
will usher-in a warmer and more humid air mass originating over
the Gulf. Moist isentropic ascent along the upper-reaches of
the warm front and low-level convergence/moist ascent along the
surface front should release enough CAPE, including elevated
CAPE, to generate periodic and scattered showers/thunderstorms.
Lows should reach the 50`s to mid 60`s early Sunday morning
before readings begin to moderate before daybreak as low-level
WAA strengthens ahead of and behind the surface warm front.

Cyclonic W`erly to WNW`erly flow aloft and embedded shortwave
troughs should impact our region this Sunday afternoon through
Monday. At the surface, the low may wobble ESE`ward from the
northern Great Lakes to near the Gulf of Maine, which should
allow a cold front to sweep E`ward through our CWA Sunday
evening through Sunday night. Additional scattered showers and
thunderstorms are expected along and ahead of the cold front,
amidst weak to perhaps moderate instability and moderate to
strong deep-layer bulk shear. Severe storms appear possible
Sunday afternoon into the evening, but their occurrence will be
contingent on multiple factors, including the degree of diurnal
destabilization of the warm/moist sector boundary layer. Behind
the cold front, drier weather is likely Sunday night into
Monday as a surface ridge attempts to build from the Upper
Midwest and vicinity. However, isolated rain showers remain
possible since subtle shortwave troughs aloft and attendant
surface trough axes should traverse Western and Central NY
generally from west to east.

High temperatures are forecast to reach the 70`s to lower 80`s
Sunday afternoon. Lows should reach mainly the mid 50`s to mid
60`s around daybreak Monday. Late afternoon highs should reach
the 70`s on Monday as a somewhat cooler and drier air mass
overspreads the eastern Great Lakes, behind the cold front.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
At the surface, a weak trough lingers over Western and Central
NY through this early evening before a high pressure ridge
builds from the Canadian Prairies later this evening through
12Z/Fri. Our regional surface winds should be W`erly to NW`erly
around 5 to 10 knots during the mid-morning through early
evening hours of today. Otherwise, light and variable or calm
winds are expected during the rest of the TAF period.

Primarily VFR are expected during the TAF period. However,
patchy radiation and steam mist/fog and associated MVFR to LIFR
are expected before ~13Z/Thurs and after ~04Z/Fri, especially
in/near the river and lake valleys of the Western Southern
Tier, Finger Lakes, and Eastern Lake Ontario Region. Western and
Central NY will experience mainly dry weather through 12Z/Fri.
However, isolated showers and thunderstorms may impact the
Eastern Lake Ontario Region this afternoon through ~00Z/Fri as a
surface trough axis sweeps SE`ward through that area. Brief MVFR
to LIFR and brief/erratic surface wind gusts up to 30 to 40
knots may accompany the showers and especially storms.

Outlook...

Friday through Saturday...Mainly VFR and dry weather expected.
Patchy mist or fog with MVFR or worse conditions are possible
late Friday evening and especially early Saturday morning.

Saturday Night through Sunday Night...Periodic showers and
thunderstorms with brief MVFR to LIFR are expected.

Monday...Mainly VFR and dry weather expected, but isolated
showers with brief MVFR are possible.

&&

.MARINE...
A trough lingers over eastern Lake Erie and Lake Ontario today
before a high pressure ridge begins to build from the Canadian
Prairies tonight. The ridge should settle over the eastern
Great Lakes by Saturday. This weather pattern evolution is
expected to be accompanied by variable winds around 5 to 10
knots and waves of 2 feet or less.

The ridge should begin to exit E`ward Saturday night through
Sunday morning and allow a warm front to sweep NE`ward across
eastern Lake Erie and Lake Ontario as a low wobbles E`ward
across the northern Great Lakes. The warm front passage should
cause mainly E`erly to SE`erly winds around 5 to 15 knots to
veer to S`erly to SW`erly. Waves of 3 feet or less are
expected.

The low should wobble ESE`ward from the northern Great Lakes to
near the Gulf of Maine later Sunday through this Monday and
allow a cold front to sweep E`ward across eastern Lake Erie and
Lake Ontario Sunday evening through Sunday night. Behind the
front, a ridge should attempt to build from the Upper Midwest
through this Monday. S`erly to SW`erly winds around 5 to 15
knots ahead of the cold front veer to mainly W`erly to NW`erly
behind the front. Waves should remain 3 feet or less.

Note: periodic showers and thunderstorms should impact eastern
Lake Ontario this afternoon into early evening and Lakes Erie
and Ontario this Saturday night through Sunday night. Showers
and especially storms may produce localized/brief strong winds
and larger waves.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.

&&

$$

DISCUSSION...Jaszka
AVIATION...Jaszka
MARINE...Jaszka