796
FXUS61 KBUF 311041
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
641 AM EDT Sun Aug 31 2025

.SYNOPSIS...
Expect an extended period of dry weather for the later half of the
Labor Day holiday weekend and into the first half of the week, as
surface high pressure dominates overhead of the Great Lakes. Cool
nights, will give way to mostly sunny and warm afternoons, as there
will be a day to day warming trend through the early portions of the
week. The next chance of rain will arrive in the later half of the
week with a cold frontal passage.

&&

.NEAR TERM /THROUGH TONIGHT/...
Surface high pressure sliding east across the lower Great Lakes
today before becoming parked overhead tonight will support dry
weather to persist.

With the mainly clear skies early this morning, ample radiational
cooling will support temperatures to fall below model guidance, so
leaned towards the the lower end of the NBM distribution, especially
across the Southern Tier supporting lows to fall into the mid 30s
briefly across the cooler valleys, though upper 30s to low 40s will
be more common.There may be some light, patchy frost in a few spots,
but coverage will not be enough to justify an advisory.
Additionally, expect typical river valley fog as well across the
Southern Tier early this morning.

Despite the cool start today, daytime temperatures will be a few
degrees higher than the day prior, as 850mb temperatures climb
toward 10 degrees Celsius. This will result in highs in the low to
mid 70s across much of the area.

Similar to early this morning, clear skies again tonight will
support another cooler night with lows tumbling into the low to mid
40s across the Southern Tier and upper 40s to low 50s elsewhere.
Additionally river valley fog will likely develop across the
Southern Tier.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A sfc high over the area to start the period will slowly shift east
through Tuesday, providing for mostly dry conditions across the
entire area to end the holiday weekend and to start the new work
week. The exception to this will be for portions of the north
country later Tuesday where some showers may be possible. This will
occur as a weak upper level trough over the region for most of the
period pulls some Atlantic moisture into the area and daytime
heating increases instability some. Additional guidance is starting
to increase this potential for later Tuesday as well.

With the sfc high over and then shifting east through the period,
temperatures will continue to warm some for both Monday and Tuesday,
with both days in the low 70s to near 80.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
During the remainder of the week upper-level ridging will amplify
across western North America...while downstream a deepening upper-
level trough will once again overspread the Great Lakes and
Northeast. Meanwhile at the surface...an attendant...elongated
surface low and cold front will make their way east and across our
region...with forcing and moisture return along/ahead of this
boundary currently looking sufficient for another round of fairly
numerous showers...and perhaps a couple embedded thunderstorms
depending upon its timing.

Speaking of which...the various guidance packages continue to
exhibit quite a bit of spread with respect to the timing of this
next system...with this likely to be a function of just how much
phasing occurs with a possible southern stream trough/surface wave.
This results in an envelope of possibilities ranging from Wednesday
night/Thursday on the fast end to Friday/Friday night on the slow
end...with the consensus currently lying somewhere in the Thursday/
Thursday night time frame. Given the resulting uncertainty...have
leaned more toward the latter and have capped PoPs in the likely
range for now for areas east of the Genesee Valley. For areas
farther west, categorical POPs have been introduced as certainty is
starting to increase for the rain potential in these areas.

Behind the passing cold front, cooling temperatures at the sfc and
aloft along with a lingering trough and cyclonic flow, lake
enhanced/effect rain will develop downwind of both Lake Erie &
Ontario. Timing of this will be dependent on timing of fropa, but
currently looks like Friday night through Saturday will have this
potential. Gusty winds will also be possible late in the week and
into the start of the weekend with the frontal passage, CAA and
height falls.

What is more certain is that the gradual warming trend from earlier
in the week will be brought to an abrupt halt by the passage of this
system...with the much cooler airmass following in its wake driving
temps back to notably below normal levels by the end of the week/
start of next weekend.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 12Z, mainly clear skies dominate the region supporting
widespread VFR conditions, due to surface high pressure sliding
overhead this morning. Due to the clear skies, ample radiational
cooling has allowed for typical river valley fog to develop across
the Southern Tier. and Black River early this morning creating local
LIFR conditions.

The valley fog will burn off by mid morning, leaving VFR to prevail
today with scattered diurnal cumulus with VFR bases inland from Lake
Erie and Lake Ontario midday through afternoon. River valley fog
will again be possible tonight, likely developing after 06Z Monday.

Outlook...

Monday through Wednesday...Mainly VFR. Local IFR in river valley fog
each late night and morning across the Southern Tier.

Thursday...MVFR with rain showers and gusty winds along a cold
frontal passage.

&&

.MARINE...
Moderate northwesterlies will continue to weaken below Small Craft
Advisory conditions across the western end of Lake Ontario this
morning with waves continuing to be choppy.

High pressure will then settle over the eastern Great Lakes Sunday
through Labor Day with light winds and flat wave action.

&&

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

&&

$$

SYNOPSIS...EAJ
NEAR TERM...EAJ
SHORT TERM...SW
LONG TERM...JJR/SW
AVIATION...EAJ
MARINE...EAJ