Scio, New York Weather Forecast Discussion

866
FXUS61 KBUF 201759
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
159 PM EDT Sat Sep 20 2025
.SYNOPSIS...
Canadian high pressure will move from western Quebec to the New
England coastline this weekend. This will keep fair and largely dry
weather intact through the weekend, with just a couple isolated
showers possible across far western New York late Sunday. The cooler
airmass associated with the high will also support some frost across
the North Country tonight, before warmer conditions return on
Sunday. A frontal system will make its way east across the Great
Lakes Monday and Tuesday, bringing increasing chances of showers and
a few thunderstorms.
&&
.NEAR TERM /THROUGH SUNDAY/...
High pressure to our north will drift to the east tonight. This will
allow for a gradually increase in some mid/high level cloud cover. A
developing southeasterly return flow should result in a milder night
for areas south of Lake Ontario, with lows in the mid 40s to mid 50s
(warmest close to Lake Erie). East of Lake Ontario, skies will
be clearer and the return flow will not develop until later on in
the night, likely allowing for enough of a window for temperatures
to briefly dip into the lower to mid 30s and allow for the
potential of some patchy frost across portions of Jefferson and
Lewis counties, for which a Frost Advisory remains in effect.
High pressure will continue to drift off to the east Sunday as a
short wave trough digs into the Upper Great Lakes. Low-end
probabilities for showers arrive into far western New York late
Sunday along a vorticity lobe that pivots into the area and
with an approaching weak warm frontal segment. Return flow
should help to get high temperatures into the 70s, with a few
lower 80s along the lake plains.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
In contrast to the recent pattern, an unsettled bout of weather is
expected this period as a a broad positively tilted trough slowly
digs southward across the Great Lakes. This will set up a deep
southwesterly flow of moisture into the region with PWATs climbing
to around 1-1.5", the upper end of this range exceeding the
climatological 90th percentile for mid/late September. As the
incipient dry airmass erodes and jet forcing increases and shifts
eastward, chances for showers and possibly a thunderstorm will
increase Sunday night through Monday, then remain elevated through
Tuesday as the primary wave of sfc low pressure treks through the
region. Confidence is highest in greatest rainfall amounts this
period lying south of the Buffalo Metro area to the NY/PA border,
with LREF probabilities depicting about a 50-60% chc of rainfall
amounts >0.75". High pressure beginning to build in from the north
behind the system`s main cold front will bring lower chances for
showers into Tuesday night though confidence in timing and precip
coverage during this period is low.
In regards to temperatures, the more abundant cloud cover and slow
southward advancement of cooler air from Canada will lead to a
modest cooling trend for daytime highs, though both daytime and
nighttime temps will continue to average above normal.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A positively tilted aggregate trough will initially extend from the
Canadian Maritimes back to the central Plains heading into midweek.
A mid-level ridge and associated wedge of sfc high pressure building
southward should lead to a general drying trend Wednesday into
Wednesday night, though uncertainty quickly grows in the forecast
details thereafter. Once the main part of the trough peels eastward
into the Canadian Maritimes, several embedded waves within the
western portion will likely phase with one another, as well as
another weak trough moving out of Manitoba later in the week, to
form a new closed system somewhere over the Mississippi Valley.
Several clusters among the LREF members indicate diverging solutions
particularly in regards to the amplitudes/positions of the eastern
ridge and developing western trough. Overall the greater chances for
rain look to be between Thurs night into Friday once the western
system further encroaches on the Great Lakes, with drier weather
potentially making a return in time for the weekend.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Canadian high pressure moving from western Quebec to New England
will provide our region with widespread VFR conditions through
tonight with a gradual increase in mid/high level clouds.
East-northeast will gusts to around 20 kts at both KBUF/KIAG
this afternoon, before lowering this evening.
Outlook...
Sunday...VFR.
Sunday night...Mainly VFR with scattered to numerous showers and a
couple isolated thunderstorms developing across western New York.
Monday and Tuesday...VFR/MVFR with showers likely along with a few
thunderstorms.
Wednesday...VFR/MVFR with a chance of showers.
Thursday...Mainly VFR with a chance of showers.
&&
.MARINE...
High pressure over western Quebec will drift east through Sunday.
East-northeast winds will continue at 15-25 knots on the western
portion of Lake Ontario (west of Irondequoit Bay) this afternoon
maintaining small craft headlines as outlined below.
Winds will weaken and veer more southeasterly tonight.
A moderate southeasterly flow is expected Sunday, with winds
veering more southerly and picking up a bit across both Lake
Erie and Lake Ontario Sunday night. Speeds should remain below
15 knots, though brief periods of 20 knots will be possible
Sunday night, especially in the eastern basins of Lake Erie and
Ontario.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement until 8 PM EDT this evening for NYZ001.
     Beach Hazards Statement until 5 PM EDT this afternoon for
     NYZ002.
     Frost Advisory from midnight tonight to 8 AM EDT Sunday for
     NYZ007-008.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LOZ042.
&&
$$
SYNOPSIS...JJR/TMA
NEAR TERM...JJR/TMA
SHORT TERM...PP
LONG TERM...PP
AVIATION...JJR/TMA
MARINE...TMA

NWS BUF Office Area Forecast Discussion