Farnham, New York Weather Forecast Discussion

372
FXUS61 KBUF 300631
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
231 AM EDT Tue Sep 30 2025
.SYNOPSIS...
High pressure will guarantee fair dry weather through
the entire week and into the coming weekend. A dry cold front will
bring a more seasonable airmass to the region tonight through
Thursday with some risk for nocturnal frost at the higher
elevations. Temperatures then climb back above normal later in
the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
The center of a strong 1033mb sfc high over northern Ontario will
slowly drift eastward to Quebec across James Bay through tonight,
ensuring fair dry weather remains in tact across the forecast area.
A trough concurrently digging south across eastern Quebec and into
the Canadian Maritimes will force a dry cold front southward into
the region through the day today. For most this will just result in
more of a northerly breeze, high temps a few degrees cooler compared
to the past few days, and the shield of high clouds stemming from TS
Imelda slowly receding southward.
CAA behind the front will bring low temps in the mid 40s tonight,
with upper 30s possible across the hilltops and east of Lake
Ontario. Should still be enough of a gradient wind in place to
preclude areas of frost from developing, though can`t completely
rule out patchier frost in some of the higher elevations inland from
the lakes.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Sprawling area of Canadian surface high pressure will be centered
just east of James Bay to open the period Wednesday morning. The
high will shift southeast across southern Quebec through Wednesday
evening before settling across eastern NY and New England later
Wednesday night through Thursday night. This will allow our stretch
of dry weather to continue, but will deliver a northeasterly flow of
much cooler air to the region. However, with the much above normal
temperatures that were in place prior to the passage of the cold
front, this will just bring daytime highs back down near normal.
This will be a bit of a different story for overnight lows with high
pressure becoming centered over eastern NY/western New England by
the second half of Wednesday night. Combining the position of the
high with light winds, clear skies, and a very dry airmass...expect
temperatures to tumble Wednesday night possibly bringing about the
necessity for frost, and possibly even freeze headlines for portions
of the eastern Lake Ontario region where the western fringe of the
core of the coolest air will be located closer to the center of the
surface high.
As the surface high shifts into southern New England, a southerly
low-level return flow will become established Thursday into Thursday
night with weak WAA ensuing. There may also be some mid/upper level
clouds passing across the area Thursday night, with both of these
factors substantially lessening the threat of frost, although some
patchy frost will still be possible across Lewis County...likely
dependent on timing of aforementioned cloud cover.
Valley fog will be possible during the overnights through mid
mornings, especially across the Southern Tier.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
High pressure remains in control through the period bringing
continued dry weather. Mid and upper level ridging will build aloft
through the period. With surface high pressure centered just south
of New England through the period and rising heights/increasing
subsidence aloft, expect another period of well above normal
temperatures.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Widespread VFR will prevail through tonight as strong surface high
pressure extends across the region from the north. The shield of
SCT/BKN cirrus extending from the tropical activity in the western
Atlantic will gradually recede southward through the morning hours.
Low confidence in how this cirrus will impact fog development in the
S. Tier (KJHW), though any local IFR/LIFR vsby restrictions will
dissipate by 13 or 14z this morning.
Otherwise, a dry cold front moving south through the region will
cause northeasterly breezes to increase today. Occasional gusts
around 20kts will be possible during the afternoon.
Fog development should be very limited tonight with a light gradient
wind persisting over the region.
Outlook...
Wednesday through Saturday...Mainly VFR. Valley fog and local IFR
possible each late night through the morning hours.
&&
.MARINE...
A strong area of surface high pressure will build east into Quebec
through tonight, then shift southeast across New England through the
rest of the week. A trough of low pressure aloft to the east of this
high will cause a dry cold front to move across the lakes from the
north today, causing northeasterly winds to increase. This will
cause SCA conditions to first develop along the southern shoreline
of Lake Ontario.
The tightening pressure gradient between the high to the north and
the tropical weather environment in the western Atlantic with cold
air flowing over the lakes will cause wind speeds to increase this
evening on both lakes. SCA conditions are expected to expand to
portions of Lake Erie while remaining in place on Lake Ontario
through Wednesday.
Wind direction will start to become more easterly and relax as the
sfc high to the north begins to move SE into Quebec Wednesday night.
The choppier wave action will subsequently subside and become
directed more offshore through the night.
Light to modest breezes and minimal wave action then expected
Thursday and especially on Friday.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...JM
LONG TERM...JM
AVIATION...PP
MARINE...PP

NWS BUF Office Area Forecast Discussion