165
FXUS61 KBUF 302323
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
723 PM EDT Tue Jun 30 2026

.WHAT HAS CHANGED...
Have adjusted PoPs and weather to include the threat of
thunderstorms, similar to this afternoon`s set up for Wednesday
night.

&&

.KEY MESSAGES...
1) Dangerous heat and humidity through Friday, then slowly lessening
heat/humidity for the holiday weekend.

2) Scattered strong to severe thunderstorms are possible today and
Wednesday.

&&

.DISCUSSION...
KEY MESSAGE 1...Dangerous heat and humidity through Friday, then
slowly lessening heat/humidity for the holiday weekend.

Building upper level ridging across, with a core of the ridge
strengthening to around 600 dm across the eastern CONUS will
continue through Thursday with the core of the ridge drifting
further east for the weekend. In its wake, a series of shortwave
troughs will dig southeastward across eastern Canada and help
flatten the ridge Friday through the holiday weekend. This being
said, 850 mb temperatures will topple out at +20C this afternoon,
and remain slightly above +20C through Thursday and possibly into
Friday. Then temperatures at 850mb will pull back into the mid to
upper teens this weekend.

In the wake of the warm frontal passage of the warm front,
temperatures this morning and early this afternoon, have warmed up
into the upper 80s and low 90s, except for the North Country where a
current bowing thunderstorm segment if passing across keeping
temperatures at bay and in the upper 70s. These temperatures coupled
with the dewpoints surging into the lower 70s, heat indices will
surge well into the mid 90s and even towards the low 100s range this
afternoon. As such, Heat Advisories remain in effect areawide this
afternoon.

Heat and humidity will continue Wednesday before reaching its peak
on Thursday, supporting daytime highs away from any lake influences
and higher terrain to surge into the lower to mid 90s for many
areas, while the climatologically warmer spots will warm up into the
upper 90s. Meanwhile, dewpoint temperatures will also climb up into
the lower to mid 70s Wednesday and linger through Thursday,
supporting dangerous and oppressive heat indices in the low to mid
100s across Niagara, Orleans, Monroe, Livingston, Ontario, Wayne,
Northern Cayuga, and Oswego counties, supporting Extreme Heat
Warnings, and upper 90s to low 100s elsewhere, continuing the Heat
Advisories elsewhere.

Gradually relief to the heat and humidity will begin Friday and
continue through the holiday weekend as the strong upper level ridge
slowly flattens and retreats southeastward. This will not only
allow for multiple shortwave troughs to ripple along the northern
periphery of the ridge, but also bring corresponding cooler
temperatures aloft. While there will be some relief to heat indices
on Friday, the 4 days of consistent heat will support Extreme Heat
Warnings to continue into Friday. While cooler temperatures will
grace the area this weekend, should note that the humidity will also
linger.

KEY MESSAGE 2...Scattered strong to severe thunderstorms are
possible today and Wednesday.

An MCS is in the midst of crossing southeast across the North
Country this afternoon bringing widespread damaging winds, large
hail and possibly a tornado. This bowing line segment will soon
exit the area within the next hour.

Similar to this afternoon, another cluster of storms may develop
over Canada and dive southeastward across areas southeastward of
Lake Ontario (from Niagara County to the Genesee Valley through the
North Country) Wednesday afternoon and evening. Strong instability
will again support a risk for strong to severe thunderstorms capable
of producing damaging winds and hail. This being a said, a Slight
Risk for Severe Thunderstorms exists across much of the Niagara
Frontier and east and southeastward across the Genesee Valley and
into the North Country.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Mainly dry weather and VFR flight conditions should tend to prevail
tonight, though some additional showers/storms and associated
restrictions cannot be completely ruled out across the North
Country. Late tonight, some patchy MVFR stratus could form across
the interior of the Southern Tier and North Country.

Outlook...

Wednesday...Possible MVFR ceilings across the Southern Tier and
North Country early...otherwise mainly VFR with a chance of showers
and thunderstorms east of Lake Ontario.

Thursday...Mainly VFR.

Friday and Sunday...Mainly VFR with a chance of showers and
thunderstorms.

&&

.MARINE...
In the wake of a warm frontal passage today, modest to moderate
southwesterlies will linger through the remainder of the week.

Scattered showers and thunderstorms Wednesday afternoon and evening
may produce locally higher winds and waves. The risk will be
greatest across Lake Ontario.

&&

.CLIMATE...
Dangerous heat and humidity are expected across western and
north central NY this week. Here are the record maximum and high
minimum temperatures for Buffalo, Rochester, and Watertown.

                    6/30        7/1         7/2         7/3
Buffalo, NY
High Max          94(1963)    93(1963)    94(1966)    94(1949)
High Low          73(1941)    75(1901)    75(1931)    74(1911*)

Rochester, NY
High Max          96(1964)    96(1901)    99(1931)    100(1911)
High Low          72(2014)    76(1931)    76(1931*)   75(1911)

Watertown, NY
High Max          89(1977)    92(1967)    92(1966)    91(1966)
High Low          73(2014*)   74(2014)    73(2002)    74(1973)


Average Temperatures for June 30-July 3
Buffalo
Max           79
Min           62

Rochester
Max           82
Min           62

Watertown
Max           78
Min           57

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Heat Advisory until 8 PM EDT this evening for NYZ001>008-
     010>014-019>021-085.
     Extreme Heat Warning from noon Wednesday to 8 PM EDT Friday
     for NYZ001>006-013-014.
     Heat Advisory from noon Wednesday to 8 PM EDT Friday for
     NYZ007-008-010>012-019>021-085.
MARINE...None.

&&

$$

DISCUSSION...EAJ
AVIATION...TMA
MARINE...EAJ
CLIMATE...