Grindstone, New York Weather Forecast Discussion

337
FXUS61 KBUF 070158
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
958 PM EDT Sat Sep 6 2025
.SYNOPSIS...
Cool weather with periodic lake effect rain showers will persist
tonight through Sunday in the wake of a cold front. Drier weather
arrives Monday as high pressure builds over the region, with a
warming trend then emerging through midweek.
&&
.NEAR TERM /THROUGH SUNDAY/...
Water vapor imagery shows a large long wave trough centered over the
Great Lakes southward into the mid and upper Mississippi Valley with
multiple shortwave troughs cycling through the region.
The core of the 500mb cold pool will move by to our northwest
tonight through Sunday. Temperatures at 850mb will continue to fall
into the +3C to +5C range across the forecast area and provide
support for lake effect showers. Following the brief period of
mainly dry weather this evening, moisture will increase ahead of an
approaching shortwave trough, which is evident with radar imagery
showing scattered showers to our west and northwest associated with
this feature. A southwest flow will become well aligned in the
boundary layer and showers will develop east-northeast of the Lakes
overnight. Rainfall amounts will be localized with most areas seeing
little to nothing and lakeshore locations seeing up to 0.25". Flow
will then veer directing lake showers more east to east-southeast of
the Lakes Sunday, mainly through midday/early afternoon. Rainfall
amounts will be localized east of Lake Ontario with some locations
seeing up to 0.25". A few rumbles of thunder can`t be ruled out
close to the lakeshores Sunday morning. Deeper moisture gets
stripped away Sunday afternoon with lake effect activity becoming
more sparse. Most of the shower activity will be confined to lake
effect areas with little to nothing elsewhere. Prepare for another
autumn-like day Sunday, with highs in the 60s.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Deep longwave troughing draped from eastern Canada to the Great
Lakes and Northeast will gradually flatten and recede back north of
the Canadian border in the Sunday night-Monday night time frame...
while sprawling surface-based ridging builds from the Midwest to New
England. Lingering cyclonic flow and moisture will help keep the
chance of some lake effect rain showers east-southeast of Lake
Ontario Sunday night...with increasing drying/subsidence attendant
to the surface ridge then bringing an end to these Monday morning.
Outside of the above...our region can expect dry weather and mainly
clear skies to predominate through Monday night...along with
generally light winds. This will result in prime conditions for
radiational cooling both Sunday and Monday nights...with this
potentially enough to result in the development of some patchy frost
across far interior portions of the Southern Tier and North Country
on both occasions. With this in mind...have undercut blended
guidance somewhat to better account for this possibility. In
between...highs will remain confined to the mid-upper 60s (with
lower 60s across the higher terrain) on Monday.
Tuesday through Wednesday the core of the surface ridge will slide
across the Canadian Maritimes and out to sea...with lingering weaker
ridging extending back southwestward to the New England and mid-
Atlantic States. This will result in a continuation of fair dry
weather... with the combination of ongoing airmass modification and
modest warm air advection helping temperatures to rebound back to
near normal levels.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
The beginning of this period will feature the passage of a cold
front sometime between later Wednesday night and Thursday...as the
large-scale trough over eastern Canada briefly reamplifies. This
being said...this next front looks to only be accompanied by very
limited moisture...which should result in it passing through our
region with little fanfare. Following its passage...Canadian high
pressure will settle back across the Great Lakes and Northeast
through the rest of the period. This will result in more fair dry
weather...with somewhat cooler temperatures Thursday and Friday
perhaps starting to give way to some limited warming on Saturday.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR conditions will continue across the forecast area through this
evening. Cold air aloft and increasing moisture will support
developing lake effect showers east of Lake Erie and Lake Ontario
for the second half of tonight through the early to middle part of
Sunday afternoon. MVFR conditions are possible within the lake
effect activity, mainly across KJHW and KART late tonight through
Sunday morning. There could be an isolated thunderstorm, mainly
close to the Lakes Sunday morning.
Widespread VFR flight conditions will return Sunday afternoon. As
instability increases through the second half of the day, expect VFR
diurnal cu to blossom inland of lake breeze circulations, then
dissipate around sunset with the loss of daytime heating.
Outlook...
Sunday night...Mainly VFR. Localized MVFR with a chance of showers
east through southeast of Lake Ontario. Localized valley fog across
the Southern Tier.
Monday...Mainly VFR. Slight chance of showers and MVFR east of Lake
Erie and Lake Ontario.
Tuesday through Thursday...VFR.
&&
.MARINE...
Winds will remain elevated on Lake Erie this evening supporting a
brief period of marginal SCA conditions.
After winds on Lake Erie relax late this evening, winds on both
Lakes will start to strengthen again late tonight, especially on
central and eastern Lake Ontario where another round of Small Craft
Advisories (see below) will be on tap for Sunday into Sunday night.
Stronger winds will be mainly westerly Sunday, becoming
northwesterly Sunday night. With the cool airmass overhead, lake
effect rain showers, thunderstorms, and waterspouts will also be
possible at times. The primary timeframe of concern for these will
be the second half of tonight through Sunday morning.
High pressure building over the Lakes will cause winds to subside
Sunday night into Monday, becoming light by Monday evening.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for LEZ040-041.
         Small Craft Advisory from 8 AM to 8 PM EDT Sunday for
         LOZ043.
         Small Craft Advisory from 8 AM Sunday to 2 AM EDT Monday
         for LOZ044-045.
&&
$$
SYNOPSIS...HSK/PP
NEAR TERM...HSK/JM
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...HSK/JM
MARINE...HSK/JM/PP

NWS buf Office Area Forecast Discussion