732
FXUS61 KBUF 132331
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
731 PM EDT Thu Aug 13 2026

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

&&

.KEY MESSAGES...
1.) Mainly dry weather will continue through Saturday with a few
very minor exceptions.

2.) Showers and scattered thunderstorms are likely Sunday.

&&

.DISCUSSION...
Key Message 1...Mainly dry weather will continue through Saturday
with a few very minor exceptions.

A longwave trough will remain in place over eastern Quebec and the
Canadian Maritimes through Friday, with a series of shortwaves
passing through the northwest flow aloft across northern NY and New
England. Forcing and moisture associated with these features will
remain far enough east to keep the majority of the area dry, with a
few minor exceptions.

Through early this evening, a few widely scattered showers and
thunderstorms will develop east of Lake Ontario and across the Saint
Lawrence valley as a passing shortwave interacts with diurnal
instability, the lake breeze driven convergence zone, and terrain
induced boundaries. The best coverage will be across eastern
Jefferson and Lewis counties, but even here showers will remain
scattered and uneven in nature. The showers will quickly end this
evening with the loss of daytime heating.

Another shortwave will cross northern NY Friday afternoon, and may
support a few isolated showers and thunderstorms across the Saint
Lawrence Valley, Adirondacks, and Central NY. Expect coverage of
anything that develops to remain sparse given the very limited
boundary layer moisture available. The trough will move away from
the area by Saturday, with high pressure surface and aloft providing
dry weather areawide.

Light winds and good radiational cooling will allow some patchy fog
to develop late tonight through Friday morning, and again late
Friday night through Saturday morning. The best chance of fog will
be in the typical areas across the Southern Tier river valleys,
Finger Lakes, and North Country.

Key Message 2...Showers and scattered thunderstorms are likely
Sunday.

A mid level trough will advance east across the Great Lakes Sunday,
with an associated weak surface low passing over or just north of
the eastern Great Lakes. An area of quality moisture will advect
into the region just ahead of this system, with surface dewpoints
climbing into the upper 60s to lower 70s. Forcing for ascent from
the mid level shortwave and the warm front/cold front associated
with the surface low will support a few rounds of showers and
scattered thunderstorms across the region Sunday through Sunday
night. The first round of showers may arrive as early as the pre-
dawn hours of Sunday, with additional rounds Sunday through Sunday
night.

Weak to moderate deep layer shear will be in place Sunday along the
southern edge of the westerlies across the Great Lakes. Latest model
guidance suggests an early arrival of clouds and showers Sunday,
which may limit destabilization and severe weather potential.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Scattered showers and thunderstorms will dissipate east of Lake
Ontario this evening. Most of the activity has been outside of KART,
however a shower or thunderstorm can`t be ruled out through 01z.
Widespread dry weather is expected across the region the rest
of the night. Patchy to areas of fog are expected across the
western Southern Tier to the Finger Lakes as well as the Black
River Valley late tonight. There is medium to high confidence
that IFR or below will occur at KJHW, with low confidence of a
period of IFR vsby at KART. VFR conditions are expected
elsewhere.

Fog will erode shortly after sunrise Friday. Widespread VFR
conditions are expected across the region. Diurnally driven showers
are possible across the Finger Lakes region, mainly staying outside
the TAF sites Friday afternoon.

Outlook...

Friday Night through Saturday...Mainly VFR. Late night and morning
river valley fog with local IFR across the Southern Tier.

Saturday Night through Sunday Night...Areas of MVFR. Showers and
scattered thunderstorms likely, with heavy downpours producing
local/brief IFR.

Monday...Mainly VFR with a chance of a few isolated showers.

Tuesday...VFR.

&&

.MARINE...
West winds in the 10-14 knot range will produce a light chop on Lake
Ontario and Lake Erie through early this evening. Winds will then
flip around to the northeast Friday, with wind speeds generally
under 10 knots.

East/northeast winds will increase somewhat into the 10-15 knot
range Saturday as the pressure gradient tightens modestly between
high pressure over the Ottawa Valley and low pressure advancing
through the Midwest States. This will produce a light to moderate
chop on the lakes. The approaching low will move over or just north
of the lower Great Lakes Sunday, with enough wind to produce a
moderate chop on the lakes.

&&

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

&&

$$

DISCUSSION...Hitchcock
AVIATION...HSK
MARINE...Hitchcock