Rochester, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

252
FXUS61 KBUF 041750
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
150 PM EDT Sat Jul 4 2026

.WHAT HAS CHANGED...
Minor changes to the forecast with this update.

&&

.KEY MESSAGES...
1) Showers likely at times this afternoon, along with scattered
thunderstorms. Isolated severe thunderstorms possible across the
Southern Tier and Finger Lakes.

2) Unsettled weather will continue Sunday through Monday with
occasional showers and a few thunderstorms, especially across
southern portions of the area.

3) Temperatures and humidity will continue to trend downward this
weekend following the heat wave.

&&

.DISCUSSION...
KEY MESSAGE 1...Showers likely at times this afternoon, along with
scattered thunderstorms. Isolated severe thunderstorms possible
across the Southern Tier and Finger Lakes.

Scattered showers and isolated thunder will persist this afternoon
as a series of weak, convectively modulated shortwave troughs pass
overtop the weak east-west orientated frontal zone lying overhead
the northern shore of Lake Ontario, which is currently depicted on
visible satellite imagery by the cloud cover across northern New
York as well as the rain showers across Lake Ontario on radar.
Coverage of showers and scattered thunderstorms will increase this
afternoon due to diurnal destabilization, along with the approach
of additional mid-level height falls and shortwaves. The synoptic
scale forcing, combined with any mesoscale effects (i.e lake
boundaries) will support coverage of showers to develop this
afternoon. This being said, peak coverage of showers and thunder
will be this afternoon, before dropping off this evening due to the
loss of daytime heating and as the frontal boundary continues to
drop southward across the region towards the NY/PA state line. Most
of the thunder should end by sunset as the boundary layer stabilizes.

The one caveat to any shower and storm development along the
mesoscale boundaries this afternoon with be the abound of
destabilization to occur to to the blanket of clouds overhead.
However, the breaks in cloud cover (currently across the western
Southern Tier will allow the very warm and soupy airmass to
destabilize enough to support a low end risk of severe thunderstorms
this afternoon. Effective shear will be quite weak, but a few
isolated strong to severe storms are possible in the afternoon with
peak heating. The main risk will be localized strong wind gusts from
precipitation loading and collapsing cores, mainly across the
Southern Tier and Finger Lakes. The limited severe risk will quickly
diminish early this evening with the loss of diurnal instability.

KEY MESSAGE 2...Unsettled weather will continue Sunday through
Monday with occasional showers and a few thunderstorms, especially
across southern portions of the area.

A weak mid-level trough will gradually sharpen across the Great
Lakes Sunday into early Monday, before passing across the eastern
Great Lakes late Monday and Monday night. Meanwhile at the surface,
a weak area of low pressure will develop over Ohio Sunday, and drift
east towards the Mid-Atlantic region Monday. As such a plume of
moisture will remain across Ohio and Pennsylvania and reach up into
the Southern Tier. A much drier air mass will lie just north of the
region across Ontario and Quebec, resulting in a sharp northern edge
of clouds and rain chances.

Occasional showers and a few scattered thunderstorms will continue
Sunday night through Monday across the Southern Tier in close
proximity to more favorable moisture and forcing. Rain chances will
be lower north of the NY Thruway, although there is still some
uncertainty with respect to the northern edge of the rain with this
system. The North Country will be deeper into the dry air associated
with high pressure over Quebec, and have the lowest chance of rain
through the period.

As the mid-level trough lingers across the Northeast Tuesday, it
will continue to support a few scattered showers or isolated
thunderstorms mainly inland from the lakes. Mainly dry weather will
return by Wednesday as high pressure builds into the Ohio Valley and
eastern Great Lakes.

KEY MESSAGE 3...Temperatures and humidity will continue to trend
downward this weekend following the heat wave.

As the strong mid to upper level ridge flattens and drifts off the
southeast CONUS this weekend, the heat wave can be put behind us.
Despite a muggy airmass to remain overhead today, as seen by surface
dewpoints in the upper 60s and low 70s, cloud cover will keep our
daytime highs today at bay and only support the lower 80s for highs.
This being said, the heat indices will peak in the mid to upper 80s.

Temperatures will return to typical mid summer values Sunday through
early next week, with dewpoints also pulling back into the 60s.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
An east-west orientated frontal boundary across Lake Ontario into
the North Country this afternoon, will support another afternoon of
showers and isolated thunderstorms. Due to the cloud cover, the best
chances for thunderstorms will lie across the Southern Tier this
afternoon, though timing of more organized shower and thunderstorms
continues to remain uncertain. A few storms may contain gusty winds,
especially across the Southern Tier and Finger Lakes. VFR/high end
MVFR (for areas close to the frontal boundary and associated
showers) will prevail most of the time, but any of the heavier
showers and storms will produce brief/local MVFR to IFR conditions.

The coverage of showers and thunderstorms will diminish this
evening, although a few scattered showers may continue overnight
especially across the Southern Tier and Finger Lakes. Late tonight,
chances of low stratus and associated MVFR CIGS will increase south
of Lake Ontario as northeast flow develops behind the weak cold front
sagging south of the area. Patchy IFR may develop across the higher
terrain of the Southern Tier and Finger Lakes.

Outlook...

Sunday through Monday...VFR/MVFR with occasional showers and
scattered thunderstorms. Greatest coverage of rain over the southern
half of the area. Brief/local IFR in thunderstorms.

Tuesday...Mainly VFR with a chance of a few showers and
thunderstorms, mainly inland from the lakes.

Wednesday...Mainly VFR.

Thursday...VFR/MVFR with chances for showers and thunderstorms
increasing due to an approaching cold front.

&&

.MARINE...
Light winds will remain across much of the lakes through this
afternoon, resulting in minimal wave action. In the wake of a weak
frontal boundary this afternoon, winds will become northwesterly on
Lake Ontario, and then as surface high pressure builds southward
Sunday winds will predominately become northeasterly on both lakes.
Winds to close out the holiday weekend and into Monday will remain
15 knots or lower, leaving minimal waves on the Lakes, though waves
may reach 2 feet on the western waters of Lake Ontario with a longer
fetch to the northeast wind

Scattered showers and isolated thunderstorms are expected from this
afternoon into the early evening hours today. Some storms may
produce locally stronger winds and higher waves.

&&

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

&&

$$

DISCUSSION...EAJ
AVIATION...EAJ
MARINE...EAJ