040
FXUS61 KBUF 172233
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
633 PM EDT Thu Jul 17 2025

.SYNOPSIS...
A cold front will exit east of the area tonight, with showers east
and southeast of Lake Erie and Lake Ontario ending overnight. Behind
the front, much cooler and notably less humid air will arrive for
Friday. A surface wave and cold front will bring another round of
scattered to numerous showers and thunderstorms starting late
Saturday, which may linger into a portion of Sunday. High pressure
will bring dry conditions by early next week.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
A few showers and isolated thunderstorms will continue through the
early evening hours east of Lake Ontario along the cold front before
exiting east of the area. Behind the front, cooler air aloft coupled
with very warm lake temperatures is supporting lake effect rain
showers, especially off Lake Erie. A band of lake effect showers
will continue into the evening across the western Southern Tier,
with a few embedded moderate showers. A few lake enhanced sprinkles
and light showers will continue southeast of Lake Ontario as well,
from near Rochester into the northern Finger Lakes. The airmass will
continue to grow cooler overnight, but drier air and lowering
inversion heights will bring an end to the first lake effect showers
of the unstable lake season.

Gusty winds will continue into this evening, especially southeast of
Lake Ontario where gusts of up to 35 mph will continue through
sunset before gradually diminishing overnight. A much cooler and
less humid airmass will arrive overnight, with lows dropping back
into the lower 60s on the lake plains and 50s inland.

Canadian high pressure will build into the region Friday and Friday
night guaranteeing dry and cooler weather. High temperatures in the
70s with overnight lows in the 50s, with some 40s across the
Tug and Western Dacks.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Quasi-zonal mid-level flow set up across the Great Lakes Saturday
morning will gradually give way to a trough digging south across
eastern Ontario and Quebec through Sunday. As such, surface high
pressure that was overhead Friday will move offshore Saturday as a
convectively enhanced shortwave and associated surface low moves
east from the central Great Lakes/Ohio Valley. Not only will this
pattern support heat and humidity to advect into the area, a few
scattered to numerous showers and thunderstorms will be possible
Saturday afternoon and evening. There is some potential for stronger
convection in this timeframe as deep layer shear increases to around
40kts, though the timing of the main shortwave and consequently the
amount of instability remains a bit uncertain. At this juncture this
potential appears to be greatest across the Southern Tier and
southern/central Finger Lakes region.

Some measure of shower/thunderstorm activity will likely linger late
Saturday night into Sunday morning as the system`s main surface cold
front moves through the region. Drier and more comfortable weather
will inevitably make a return as high pressure builds back into the
region from the upper Great Lakes.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Exiting mid-level troughing will support a mid-level ridge to build
across the central and eastern Great Lakes Monday and Tuesday before
zonal flow sets up mid-week. As such surface high pressure will
slide east across the central Great Lakes Monday and off the New
England coastline Tuesday, which will result in a period of dry
weather through at least the first half of Tuesday. A potential
shortwave trough gliding through the zonal flow, may support some
showers and thunderstorms Tuesday afternoon through Thursday. The
NBM appears more pessimistic compared to other long range ensembles
and thus could see the forecast trending drier, though there remains
plenty of uncertainty at this range to leave NBM`s sChc/Chc PoPs in
place for now.

Regardless of precipitation chances, the offshore deep anticyclonic
flow will cause the heat and humidity to return, especially by
midweek when some areas across the Lake Plains and Genesee Valley
could reach the low 90s.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
A cold front will continue to produce a few scattered showers and
isolated thunder east of Lake Ontario into the evening, with most of
this focusing over the Adirondacks. It will remain quite windy
through early to mid evening, especially east and southeast of Lake
Ontario where gusts may approach 35 knots. Winds will gradually
diminish overnight.

Behind the cold front, lake effect rain showers will continue
through the first half of the night across the western Southern Tier
east of Lake Erie, including near KJHW at times. A few lake effect
sprinkles and light showers will also be found southeast of Lake
Ontario near and southeast of KROC this evening. The lake effect
showers will end overnight as a much drier airmass arrives.

Areas of MVFR CIGS will continue overnight in the post frontal
airmass as a shallow layer of moisture becomes trapped beneath the
subsidence inversion. Any remaining MVFR CIGS early Friday morning
will mix out, leaving VFR to prevail.

Outlook...

Friday night...Mainly VFR with localized IFR possible in valley fog.

Saturday...Mainly VFR with a chance of showers and thunderstorms and
associated brief restrictions late in the day.

Sunday...VFR/MVFR with a chance of showers and thunderstorms, mainly
early.

Monday and Tuesday...VFR.

&&

.MARINE...
Main cold front will cross early this evening with winds becoming
north-northwest and slacken following its passage. High end Small
Craft Advisory conditions are expected on both lakes into tonight,
but calmer conditions will return Friday as high pressure builds
across the region.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement until 4 AM EDT Friday for NYZ001-002-
     007.
     Beach Hazards Statement until 6 AM EDT Friday for NYZ003>006.
     Beach Hazards Statement until 8 PM EDT this evening for NYZ010.
     Beach Hazards Statement until 10 PM EDT this evening for
     NYZ019-085.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LEZ020-
         040-041.
         Small Craft Advisory until 4 AM EDT Friday for LOZ042.
         Small Craft Advisory until 8 AM EDT Friday for LOZ043>045.

&&

$$

SYNOPSIS...Hitchcock/TMA
NEAR TERM...Hitchcock/TMA
SHORT TERM...EAJ/PP
LONG TERM...EAJ/PP
AVIATION...Hitchcock
MARINE...TMA