844
FXUS61 KBUF 250045
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
845 PM EDT Sun Aug 24 2025

.SYNOPSIS...
A much cooler airmass filtering into the Lower Lakes tonight will
bring below normal temperatures and unsettled weather through
midweek.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
A cold front is just about out of the eastern portion of the
forecast area, with the far eastern portions of the North
Country still to go, where some showers and thunderstorms will
linger for another hour or so.

Behind the front, cooler temperatures are expected along with a few
scattered showers for tonight. This will occur as a large scale
trough remains over the region. Temperatures will cool to the low to
upper 50s overnight from the higher terrain to the lower elevations
respectively. Areas of gusty winds this evening will lighten
through the night.

Cool temperatures will continue to start off the week with highs in
the 60s to low 70s Monday. As the cold air mass settles in over much
of the Great Lakes behind the large scale upper level low, 850mb
temps will drop into the single digits and reach 5-7 degC Monday
night. This will be in the climatological bottom 10th percentile for
late August with the coolest air aloft still remaining farther west
across the Upper Great Lakes. In additional to temperatures being
~10 degF below normal Monday, cooler air aloft over warm lake
surface temperatures will support the development lake effect rain
showers early Monday morning continuing into Monday night east of
Lakes Erie and Ontario. A mid-evel shortwave passage Monday
afternoon within the large scale troughing will shift the focus of
rain showers more southeast of the lakes for Monday night.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Anomalously deep...full-latitude upper level troughing will remain
in place through Tuesday night...before gradually weakening and
broadening during Wednesday. Plentiful cool air aloft attendant to
this feature will result in 850 mb temps bottoming out in the middle
single digits above zero Tuesday...with some slight recovery then
following during Wednesday. At the surface...this will result in
highs mostly in the mid to upper 60s on Tuesday (with some lower 60s
across the higher terrain)...and maybe getting a degree or two
higher Wednesday. In between...lows Tuesday night will range from
the 40s to lower 50s. Overall...such readings will be some 10 to 12
degrees below late August normals.

The much cooler airmass and general westerly to west-northwesterly
flow will also result in an environment favorable for lake effect
rain showers east/east-southeast of the lakes each night and early
morning...with the best band organization during this period off
both lakes expected Tuesday morning. During the day Tuesday...strong
late summer diurnal influences and the approach of the main upper
trough axis will result in this activity weakening and transitioning
to more general diurnally-driven instability showers and isolated
thunderstorms...with some small hail again a possibility. After some
modest reorganization for a time Tuesday night...building low-level
ridging...associated drying/subsidence...and renewed diurnal effects
should result in any lingering lake effect showers weakening and
eventually falling apart east of the lakes during Wednesday...with
generally dry weather found elsewhere.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
In the extended portion of the forecast...the medium range guidance
packages have started coming into somewhat better agreement on the
late week cold frontal passage...with the timing of this now
generally looking to be sometime between later Thursday and early
Friday. Blended guidance has some general 20-40% PoPs for some
showers and possibly a few thunderstorms during this time frame...
which looks reasonable given trends over the past couple of days and
our still somewhat-distant vantage point.

After that...forecast uncertainty increases quite a bit again as
some of the guidance (most notably the GEM and ECMWF) has recently
started to show the development a fairly deep closed low over New
England next weekend. Were this to verify...it could potentially
keep at least somewhat unsettled conditions in place through the
upcoming weekend. Meanwhile other guidance does not show this at
all...with just broad troughing lingering aloft while surface-based
ridging settles across our area...which would generally result in
fair weather. Given the only very recent depiction of a stronger
closed low in some of the guidance...for now will continue to lean
toward a drier and more optimistic forecast for next weekend...
however this will need to be watched.

All this being said...the presence of at least some troughing aloft
will guarantee that temperatures will continue to average out below
normal during this period...though likely not quite to the extent of
earlier in the week.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Mainly VFR conditions expected with a brief period of clearing
behind an earlier passing cold front. Scattered lake showers will
develop overnight, especially near KJHW off Lake Erie and KART off
Lake Ontario headed into early Monday morning. Gusty westerly winds
are expected for area terminals by late Monday morning.

Monday, lake effect showers east of both lakes Monday morning will
bring the potential for lower flight cats to MVFR at JHW/ART,
otherwise mainly VFR expected. Some additional showers expected for
later in the day across much of the area with some lower CIGs
possible around the MVFR/VFR levels, especially where there is some
lake enhancement.

Outlook...

Monday night through Tuesday night...VFR/MVFR. Lake effect rain
showers each night/morning downwind of the lakes...then a more
general chance of showers and embedded thunder each afternoon/early
evening.

Wednesday...Mainly VFR with diminishing lake effect rain showers
downwind of the lakes.

Wednesday night into Thursday...Mainly VFR.

Thursday night into Friday...VFR/MVFR with scattered showers with a
frontal passage.

&&

.MARINE...
With the departure of a cold front this evening, a much cooler
airmass will begin to filter in across the Lower Great Lakes. Given
the cooler airmass aloft and warmer lake temps, we should see decent
over water mixing beginning to take place overnight. This will more
than `likely` lead to SCA conditions Monday on area lakes which may
last through Tuesday night. Additionally...we will have the
potential for lake effect rain showers off both lakes...as well as
waterspouts beginning late tonight.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ040-
         041.

&&

$$

SYNOPSIS...AR
NEAR TERM...Brothers/SW
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...Brothers/SW
MARINE...AR