Clarendon, New York Weather Forecast Discussion

692
FXUS61 KBUF 180554
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
154 AM EDT Thu Sep 18 2025
.SYNOPSIS...
High pressure will maintain dry weather through most of today. A
weak cold front will then drop south across the area very late today
and tonight while generating some sprinkles and widely scattered
light showers. Strong Canadian high pressure will then build
southeast across the region through the first half of the weekend
and bring a return to dry and cooler weather. The high will then
slide off the east coast Sunday...with a southerly return flow of
warmer air on its backside overspreading our region through early
next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Today lingering surface-based ridging over our area will gradually
weaken in place. Meanwhile broad upper-level troughing digging
across Quebec will help to push an attendant surface low across
Labrador...with its associated weak trailing cold front sagging
south to the Saint Lawrence Valley and Lake Ontario by late in the
day. While this feature will only be accompanied by limited moisture
and a weak shortwave...this in tandem with some weak instability and
low level convergence along the boundary may still be sufficient to
trigger a few isolated to widely scattered showers across the North
Country/Saint Lawrence Valley and Niagara Peninsula/Niagara county
late in the day. Otherwise dry and warm weather will continue to
prevail...with any patchy overnight fog mixing out this morning.
Highs will generally range from the mid 70s to lower 80s.
The weak cold front will then ease its way south across our region
tonight. While synoptic moisture will remain limited...moisture
contributions from the lakes and increasing upsloping will prove
sufficient to support the development of a swath of lower clouds and
possibly some sprinkles and/or widely scattered light showers east
and then south of Lake Ontario as we push through the night.
Otherwise lows will range through the 50s south of Lake Ontario...
with the North Country dropping into the upper 40s late.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Surface high pressure will build into the eastern Great Lakes region
Friday. Low level moisture will be slow to retreat behind a cold
front, so expect mostly cloudy conditions across interior portions
of western NY through mid-morning hours. As drier air works into the
region, mostly sunny skies will return across the region by Friday
afternoon. Cooler than recent days, with highs in the upper 60s to
low 70s, mid 70s in valley locations near the NY/PA border and Upper
Genesee valley.
High pressure centered over northern Ontario and Quebec will
continue to build into the region Friday night. While the high isn`t
directly overhead, clear skies and light winds may result in some
locations decoupling. Min temperatures will fall to the 40s, with
some locations near the Tug Hill reaching the mid to upper 30s.
Patchy frost is possible, mainly across Lewis county.
Surface high pressure and an upper level ridge overhead will
maintain dry weather this weekend. A southerly flow will increase
Sunday, with temperatures and dewpoints rising 10-15 degrees
compared to Saturday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
The pattern becomes more progressive next week, with the potential
for a few weak disturbances across the Great Lakes region. An upper
level ridge will hold on to the eastern seaboard and parts of the
Northeast. While there will be an uptick in moisture as a broad
southwesterly flow sets up, generally scattered, light showers,
maybe a thunderstorm is forecast for next week. Temperatures will
average above normal for the first half of next work week.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Most areas will continue to experience VFR conditions through
sunrise. This being said...some fog and associated restrictions will
be possible within the Southern Tier river valleys and Black River
valley east of Lake Ontario...with this potentially affecting KJHW
and KART respectively. Some fog/low clouds over the Niagara
Peninsula may also expand eastward and bring some restrictions to
KIAG through early this morning.
Any fog that develops will then mix out after sunrise this
morning...with VFR conditions otherwise expected to prevail
through the day. A weak cold front will then cross the region
from north to south late today and tonight...with both the front
and the developing northerly upslope flow behind it possibly
generating some sprinkles and/or widely scattered light showers
in the process. Of more importance to aviation interests...the
aforementioned developing upslope flow will also result in the
development of a swath of lower clouds from north to south
tonight...resulting in ceilings falling into the MVFR/IFR ranges
in most locations.
Outlook...
Friday...Early morning LIFR to MVFR ceilings south of Lake Ontario
improving to VFR.
Friday night through Sunday...Mainly VFR, with southern Tier valley
fog possible each overnight/early morning.
Monday...Mainly VFR with a chance of showers.
&&
.MARINE...
High pressure slowly weakening in place across our region will bring
mainly light winds and minimal waves through the first half of
today. The pressure gradient will then tighten out ahead of an
approaching weak cold front this afternoon and bring a period of
somewhat elevated southwesterly to westerly flow...though conditions
should still remain well below Small Craft Advisory criteria.
The cold front will then cross the Lower Great Lakes tonight...with
the freshening northerly flow in its wake bringing near-SCA to low-
end SCA conditions to eastern portions of Lake Ontario later tonight
into Friday morning.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...JJR
NEAR TERM...JJR
SHORT TERM...HSK
LONG TERM...HSK
AVIATION...JJR
MARINE...JM/JJR

NWS BUF Office Area Forecast Discussion