221
FXUS61 KBUF 171026
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
626 AM EDT Thu Jul 17 2025

.SYNOPSIS...
Low pressure over Lake Huron will track northeastward into Quebec
today...and in the process will push a pair of cold fronts across
the region between this afternoon and evening. These will bring some
additional...mainly scattered showers and thunderstorms to the
region today...with the greatest convective coverage expected east
of Lake Ontario this afternoon. It will also turn rather breezy to
windy today...particularly northeast of Lakes Erie and Ontario where
winds could briefly gust to as high as 45 mph. Following the passage
of the secondary cold front...cooler and notably drier air will
overspread our region for Friday and Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Yet another shortwave will quickly make its way into far western New
York early this morning...before sliding east across the rest of the
area through early this afternoon. Meanwhile at the surface...low
pressure will simultaneously make its way from Lake Huron to
southwestern Quebec...with a subtle trailing prefrontal trough and
initial cold frontal boundary pushing across the area more or less
in tandem with the aforementioned shortwave. These features will
serve as the impetus for another round of weaker/mainly scattered
showers and thunderstorms across western New York...with the
activity then tending to strengthen some and become more numerous as
it encounters a progressively more unstable environment east of Lake
Ontario during the midday and early afternoon hours. With modest
instability and 30-35 knots of bulk shear in place along with PWATs
of close to 2 inches across eastern portions of our area...any
storms east of Lake Ontario will have the potential to produce
locally heavy rainfall and strong wind gusts.

In the wake of the prefrontal trough/initial cold front...subsidence
and dry slotting aloft should result in conditions then tending to
dry out pretty quickly from west to east between late this morning
and late afternoon. The arrival of the secondary cold front late in
the day/early this evening may then produce a few more scattered
showers and storms east of Lake Ontario...while drier air aloft
should help to maintain largely dry conditions further west across
western New York. Cooler and notably less humid air will then
overspread our region in the wake of the secondary front tonight.

It will also turn rather breezy to windy today in association with
the passage of the initial cold front...as daytime heating will help
to at least partially mix down higher momentum air from aloft
(attendant to a passing 40-45 knot low level jet) to the surface.
This will especially be the case in the typically favored areas
northeast of the lakes...where there could be a rather brief period
of gusts pushing low-end Wind Advisory criteria (rather atypical for
July). Given the expected very brief nature of the strongest
gusts...will hold off on any advisories at this point in time.
Further inland...wind gusts will tend to peak in the 30-40 mph range.

Otherwise...expect one more warm and rather humid day today...with
daytime highs mostly ranging from around 80 east of Lake Erie to the
mid and upper 80s across the Finger Lakes. Coupled with surface
dewpoints in the lower 70s...this could result in a few isolated
spots in the Finger Lakes seeing apparent temperatures briefly
tickle 95F...however the brief and highly localized nature of this
precludes the need for a Heat Advisory at this time. Much more
comfortable conditions will then overspread the area tonight...with
surface dewpoints falling off into the 50s...and low temps settling
into the mid 50s to lower 60s in most places.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
Quasi-zonal mid/upper level flow will be in place from the Upper
Midwest to the Northeast Friday, then be gradually supplanted by
broad scale troughing digging south from eastern Ontario and Quebec
through Sunday. An expansive area of Canadian-sourced high pressure
will guarantee dry and relatively cooler weather lasts through at
least Friday night, when a decent radiational cooling setup will
potentially cause low temps to dip into the upper 40s across the Tug
and Western Dacks, with mostly 50s elsewhere.

The high will move offshore Saturday as a convectively enhanced
shortwave and attendant wave of sfc low pressure ripples eastward
from the central Great Lakes and Ohio Valley. This will result in a
bump to temps/humidity levels as well as scattered to numerous
showers and thunderstorms across the forecast area, mainly 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/tstorm activity will likely linger late
Saturday night into Sunday morning as the system`s main sfc 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 WEDNESDAY/...
Sfc high pressure will translate from the Upper Great Lakes Monday
to off the New England coastline by Tuesday evening. This will allow
mainly dry weather to prevail through at least early Tuesday, though
a potential weak shortwave/warm front could spoil this between later
Tuesday and Wednesday. 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 precip chances, the offshore deep anticyclonic flow
will cause the heat and humidity to make a return, especially by
midweek when some areas across the Lake Plains and Genesee Valley
could reach the low 90s.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
As we push through today...low pressure will make its way from Lake
Huron to Quebec...and in the process will push an initial cold front
across the area...followed by a trailing secondary cold front late
in the day/early this evening. The bulk of any convection will
precede/accompany the initial cold front and a subtle pre-frontal
trough...with mainly scattered activity across western New York in
the morning becoming more numerous as it crosses the eastern Lake
Ontario region during the first part of the afternoon. Behind this
initial front mainly dry weather will return from west to
east...with just a couple more showers/storms possible across the
North Country during the late afternoon/early evening as the
secondary cold front pushes through. Meanwhile...a general mix of
MVFR to VFR flight conditions in the morning will tend to improve to
VFR across the lower elevations in the afternoon.

The approach and passage of the initial cold front will also usher
in a short period of rather breezy to downright windy conditions
during the late morning and afternoon hours. This will especially be
the case northeast of Lakes Erie and Ontario...where gusts to as
high as 35-40 knots are currently expected. Further inland...gusts
will mainly range from 25-30 knots.

Winds will then quickly drop off this evening with diminishing
heating/ mixing and the passage of the secondary front...however the
ensuing north-northwesterly upslope flow will result in the
development of another period of fairly MVFR ceilings...with some
limited IFR possible across the higher terrain. Gradual improvement
to VFR from north to south will then overspread the lower elevations
later on in the night.

Outlook...

Friday...Improvement to VFR areawide.

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.

Sunday...Mainly VFR.

Monday...VFR.

&&

.MARINE...
An initial cold front will cross the Lower Great Lakes today...
followed by a secondary cold front late today and early this evening.
Southwesterly winds will increase markedly with the approach and
passage of the initial cold front today, then will become north-
northwest and slacken following the passage of the secondary front
this evening. Solid Small Craft Advisory conditions are expected on
both lakes today into tonight...with calmer conditions then
returning on Friday as high pressure builds across the region.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement from 11 AM EDT this morning through
     late tonight for NYZ001-002.
     Beach Hazards Statement from noon EDT today through late
     tonight for NYZ003>005.
     Beach Hazards Statement from 3 PM EDT this afternoon through
     late tonight for NYZ006.
     Beach Hazards Statement from 2 PM EDT this afternoon through
     late tonight for NYZ007.
     Beach Hazards Statement through this evening for NYZ010.
     Beach Hazards Statement through this evening for NYZ019-085.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LEZ020.
         Small Craft Advisory until 10 PM EDT this evening for
         LEZ040-041.
         Small Craft Advisory until 4 AM EDT Friday for LOZ042.
         Small Craft Advisory from 11 AM this morning to 8 AM EDT
         Friday for LOZ043-044.
         Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
         Friday for LOZ045.

&&

$$

SYNOPSIS...JJR
NEAR TERM...JJR
SHORT TERM...PP
LONG TERM...PP
AVIATION...JJR
MARINE...Hitchcock/JJR