615
FXUS61 KBUF 031433
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1033 AM EDT Wed Sep 3 2025

.SYNOPSIS...
High pressure drifting slowly east towards the eastern seaboard will
bring dry and warm weather through the remainder of today. A cold
front will then sweep across the eastern Great Lakes Thursday,
producing a period of rain and scattered thunderstorms moving from
west to east across the area. A secondary cold front will move east
across the area Friday through Friday night with a few more
scattered showers and gusty winds. Cooler air will gradually filter
into the region over the weekend behind this cold front.

&&

.NEAR TERM /THROUGH TONIGHT/...
The weak mid level trough will move east into New England today and
weaken, with a mid level ridge building back into the eastern Great
Lakes. This will bring a return to dry weather and mostly sunny
skies, with just a few patches of high cirrus and scattered diurnal
cumulus midday into the afternoon. Dry weather will continue tonight
with mid/high clouds gradually thickening from west to east ahead of
an approaching cold front. It will become breezy tonight, especially
near Lake Erie, where gusts may reach 30 mph at times in downslope
areas to the lee of the Chautauqua Ridge.

Temperatures will run above average, with highs in the lower 80s
today for lower elevations away from the immediate lakeshores, and
mid to upper 70s for higher terrain. Lows tonight stay quite mild
with the increasing southerly breeze. Expect low to mid 60s on the
lake plains and 50s inland.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
A couple rounds of active weather this period as an anomalously deep
sub-54dm low becomes oriented over northern Ontario and the upper
Great Lakes. A pair of shortwave troughs pivoting through the base
of this larger scale trough will cause a pair of cold frontal
boundaries to swing east through the Great Lakes region, each
bringing opportunities for rain and breezy winds.

The first of these cold fronts will move through the region during
the day Thursday as the sfc low occludes over Ontario Province. As
the LLJ ahead of the front digs southward it will tap into an
additional plume of moisture across the southeastern states which
should set the stage for a bout of widespread rainfall. Guidance is
in fairly good agreement on this arriving in far western NY Thursday
morning, then shifting east of the Genesee Valley by later Thursday
afternoon. Gusty southerly winds will likely precede the rainfall
though gusts should generally remain under 30mph. NBM probabilities
remain about 50-75% for at least 0.5" of rainfall with this system,
while probabilities for >1" are 15-25% across WNY and 25-50% for the
Tug Hill region. Locally higher totals will be possible as MLCAPE
values up to 500J/kg will support a few embedded thunderstorms
within the main swath of precip, though the progressive nature of
the front and relatively dry antecedent conditions should minimize
flood potential.

The next front will then move into the region from the west later
Friday evening as the secondary shortwave and associated 995mb sfc
low pivots to western Quebec from the Great Lakes. While another
round of showers is expected with this system, mainly from the
Southern Tier to the southern Tug Hill region Friday night into
Saturday, the main concern will be on the potential for gusty winds
up across the Niagara Frontier during the day Friday into early
Friday evening. NAEFS/EC guidance continues to indicate wind speeds
aloft on the southwestern flank of the low within the 98th
percentile for early September, even exceeding 50kts at 850mb. While
this could suggest advisory-level winds, there remains the question
of how efficiently this will be able to mix to the surface as many
of the other factors seem marginal if not unfavorable...Including
temp advection regime, timing of the sfc low deepening, and track of
the low itself. At the very least gusts to 40mph will be possible
across the Niagara Frontier, though will need to continue to monitor.

Otherwise...While temps will be variable on Thursday and relatively
seasonable Friday, with the secondary frontal passage daytime highs
will be near 10 degrees below normal just about everywhere on
Saturday.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
A cool Canadian polar airmass will continue to spill into the region
behind a secondary cold front Saturday night and remain in place
through early next week as broad scale troughing dominates the
Northeast. There remains uncertainty in the timing and amount of
synoptic moisture within this trough though some measure of lake
effect rain showers appears likely east of the lakes Saturday night
into Sunday. The main trough axis will make a close approach by
Sunday afternoon which in tandem with daytime instability,
could cause showers to develop outside the main lake effect areas.

Sfc high pressure will build squarely over the eastern Great Lakes
by Monday morning, allowing mainly dry weather to return.
Temperatures will continue to run well below normal until the high
shifts east of the region, allowing for a gentle day to day warming
trend through midweek.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Weak mid level trough exits east into New England today, replaced by
a transient mid level ridge moving over the eastern Great Lakes.
This will bring dry weather with nothing more than a few high/thin
cirrus and scattered diurnal cumulus with VFR bases midday through
the afternoon.

VFR will continue tonight with mid/high clouds gradually increasing
from west to east ahead of an approaching cold front. It will become
breezy overnight, especially near Lake Erie where winds may gust to
25 knots at times.

Outlook...

Thursday...MVFR/IFR with a period of showers and a few scattered
thunderstorms. Gusty winds also possible with the cold front.

Friday and Saturday...Mainly VFR with scattered rain showers and
gusty winds.

Sunday...Mainly VFR. Spotty lake effect rain showers possible east
of the lakes.

&&

.MARINE...
Relatively light winds will continue this afternoon, generally less
than 12 knots and waves under 2 feet. The period of light winds will
come to an end tonight as southerly flow increases ahead of an
approaching cold front. This will bring building waves in offshore
waters, with Small Craft Advisory conditions possible at the
northeast end of Lake Ontario and Lake Erie overnight through
Thursday.

There will be a brief lull in the winds Thursday night, then
southwest winds will increase significantly Friday ahead of a
secondary cold front. This will bring higher end Small Craft
Advisory conditions to Lake Erie and the western portion of Lake
Ontario. Winds will diminish over the weekend, but still be strong
enough to produce a moderate chop on Lake Erie and Lake Ontario
Saturday through Sunday.

&&

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

&&

$$

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