Forecast Discussion

876
FXUS61 KBUF 091758
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
158 PM EDT Thu Jul 9 2026

.WHAT HAS CHANGED...
Increased potential for isolated severe weather and flash flooding
tomorrow.

&&

.KEY MESSAGES...
1) Strong to severe thunderstorms expected this afternoon and
evening, with a Marginal Risk in place for most of WNY.
Additionally, heavy rainfall may produce some isolated areas of
flash flooding.

2) Strong to severe thunderstorms possible again tomorrow south of
Lake Ontario. Heavy rainfall and isolated areas of flash flooding
also possible.

&&

.DISCUSSION...
Key Message 1...Strong to severe thunderstorms expected this
afternoon and evening, with a Marginal Risk in place for most of
WNY. Additionally, heavy rainfall may produce some isolated areas of
flash flooding.

Ahead of an approaching cold front, showers and thunderstorms have
formed over most of Ontario early this afternoon, with additional
development ongoing along convergence zones off the Great Lakes.
Forecast guidance favors the south shore of Lake Ontario for the
greatest coverage of storms later this afternoon, with more
scattered activity possible elsewhere.

Any mature updrafts will have the potential to produce damaging wind
gusts and large hail, owing to 30-40 kts of deep layer shear. The
limiting factor today will be instability, and the presence of a mid
level cap, noted on the 12z BUF sounding.

Additionally, heavy rain will fall from these storms as PWATs
increase to almost 1.75", and if any training of cells occurs,
isolated pockets of flash flooding will be possible.

Later tonight, the cold front will move southeast across the area
producing additional showers and scattered thunderstorms. Although
the risk of severe weather will be low, heavy rainfall will still be
a risk with any thunderstorms.

Key Message 2...Strong to severe thunderstorms possible again
tomorrow south of Lake Ontario. Heavy rainfall and isolated areas of
flash flooding also possible.

Latest guidance this morning has trended towards a slower passage of
the cold front to our south and into PA. This will keep low and mid
level moisture in place, and with surface heating later in the day,
moderate instability is likely to develop on the order of 1500-2000
J/kg MUCAPEs. Deep layer shear will be weaker (20-30 kts), but still
enough to sustain robust convection, which will keep the potential
for damaging wind gusts and large hail in the forecast tomorrow
south of Lake Ontario.

With a high PWAT airmass still in place across the Southern Tier,
heavy rainfall from storms will bring the potential for isolated
areas of flash flooding, especially in terrain areas and locations
that saw heavy rain earlier this week. Showers and thunderstorms
will taper off from north to south with loss of heating tomorrow
evening, as the cold front finally pushes south of the region.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Scattered showers and thunderstorms developing early this afternoon
along lake breeze boundaries inland from Lakes Erie and Ontario with
reductions to MVFR/IFR conditions most likely to occur near KIAG,
KROC, and KART through early this evening. Showers will linger
overnight along the cold frontal passage in addition to lowering
ceilings to MVFR/IFR levels. As the cold front slowly moves south,
additional showers will develop in the morning along with
thunderstorms midday that may lead to further flight restrictions.

Outlook...

Friday Afternoon...Additional showers and thunderstorms likely at
times across interior sections with a mix of MVFR/IFR ceilings
gradually improving through the afternoon and evening.

Saturday through Tuesday...Mainly VFR.

&&

.MARINE...
A brief period of 10-15 knot winds ahead of an approaching cold
front may cause some light to low-end moderate chop on the lakes
this afternoon into the early evening. Otherwise, mainly light winds
and negligible waves are expected through the end of the work week.

A few stronger thunderstorms will be possible on Lake Ontario later
this afternoon into the early evening, capable of producing locally
higher winds and waves.

&&

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

&&

$$

DISCUSSION...SGK
AVIATION...Brothers
MARINE...JM

NWS BUF Office Area Forecast Discussion