-- Discussion containing changed information from previous version are highlighted. --
275
FXUS61 KBUF 241440
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1040 AM EDT Wed Jul 24 2024

.SYNOPSIS...
-- Changed Discussion --
A humid airmass will linger across our region through tonight,
supporting several rounds of showers and thunderstorms with uneven
coverage. A cold front will cross the eastern Great Lakes late
tonight and early Thursday, bringing a return to drier and less
humid weather to end the week. Dry weather will last through the
weekend into early next week, but heat and humidity will build.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
Subtle shortwave crossing the region early this morning continuing
to generate isolated showers and thunderstorms east of Lake Ontario,
but much of these are now weakening and exiting the area. A few more
showers may develop east of Lake Ontario through early afternoon.
A line of thunderstorms is developing just upstream from near
Hamilton to west of Long Point. The movement is northeast on these
storms, and they will likely have a difficult time initially moving
into the developing stable lake shadow northeast of Lake Erie.

A mid level trough will gradually work into the region from the
central Great Lakes today with the surface reflection/low moving
from lower Michigan this morning into southwest Quebec by early
this evening. Associated cold front remaining upstream through
today, although a pre-frontal trough will start to enter western
New York later this afternoon. Increasing instability will
likely be supportive of increasing showers and thunderstorms
this afternoon as the pre-frontal trough works into the region,
enhanced by some lake breeze interaction. Expect the best
chance of showers and thunderstorms to be found along and inland
of the lake shadowing from the Southern Tier through the
Genesee Valley and Finger Lakes to the southern Tug Hill. A
southwest flow off Lakes Erie and Ontario will lower rain
chances across the Niagara Frontier and Jefferson County most of
the day.

A few severe storms are possible as moderate instability develops in
the warm/moist sector boundary layer amidst shear profiles with
around 30 knots effective shear magnitudes. Locally damaging
wind gusts appears to be the main threat. In addition to the
risk for severe weather, a heavy rainfall risk is also a concern
with high atmospheric moisture content and the threat for
training cells will bring about the potential for localized
heavy rainfall and flash flooding.

The shower and thunderstorm potential will end gradually from
northwest to southeast late tonight as the cold front starts to
move into the region.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Cold front will quickly exit our region to the east Thursday.
Showers will linger, especially east of Lake Ontario where 850 hPa
temperatures falling into the upper single digits Celsius will
generate lake enhanced activity, coupled also with the passage of
the upper level trough that will linger scattered showers through
the day. Variable cloudiness Thursday will feature clouds ending
Thursday evening east of Lake Ontario with the exit of the trough,
and its associated moisture aloft.

High pressure will advance towards the eastern Great Lakes the
balance of this period, providing for plenty of sunshine, fair
weather and less humidity. Cool both Thursday night and Friday night
with traditionally colder spots of the Southern Tier and Tug Hill
region possible dipping into the upper 40s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Over the weekend the axis of surface high pressure will gradually
drift from the Lower Great Lakes to the Atlantic coastline...while
upper-level ridging builds in aloft. This will lead to fair dry and
warm weather for the weekend...with highs in the upper 70s to mid
80s Saturday nudging up a category on Sunday as heights/subsidence
increase aloft and a modest southwesterly flow of warmer air begins
to set up behind the departing surface ridge. Meanwhile humidity
levels will remain comfortable through Saturday as surface dewpoints
largely remain in the 50s...before beginning to creep up a little on
Sunday.

As we move into next week...conditions will turn progressively more
uncomfortable as an increasing/deepening southwesterly flow sets up
across our region in advance of a slowly approaching mid/upper level
trough. This will allow high temperatures to reach into the mid 80s
to lower 90s both Monday and Tuesday...while nightly lows climb to
the mid 60s to lower 70s by the end of the period. At the same time
humidity levels will also continue an upward arc...with surface
dewpoints rising to the upper 60s/lower 70s in many places by
Tuesday. The building heat and humidity will also allow for the
possibility of some widely scattered diurnally-driven convection
across far western New York Monday...before better and more general
chances for showers and storms arrive on Tuesday with the approach
of the upper trough axis.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Mainly VFR conditions are expected through late morning or
midday with dry weather prevailing in most areas, with the exception
of a few scattered showers east of Lake Ontario mainly east of KART.

Showers and thunderstorms will increase in coverage this afternoon
as a mid-level trough approaches, and with daytime heating. The
focus for showers and thunderstorms will be along and inland of
the lake breeze boundaries. Stable lake shadows will hold down
rain chances over and northeast of Lake Erie and Lake Ontario,
including KBUF and KART. Pinpointing exact timing remains
difficult with these generally unorganized storms.

Outlook...

Tonight...Showers and thunderstorms likely with areas of MVFR
CIGS.
Thursday...Mainly VFR with a chance of showers and thunderstorms
mainly east of Lake Ontario.
Thursday night through Sunday...Mainly VFR. Valley fog possible
mainly across the Southern Tier with local IFR each overnight
through early morning.
-- End Changed Discussion --

&&

.MARINE...
Winds are expected to remain relatively light through much of the
week. There is a chance of a few thunderstorms at times through
Thursday, although the better chances will be inland from the Lake
Erie and Lake Ontario. The best chance for thunderstorms impacting
the lakes will be late this afternoon and tonight ahead of a cold
front that will sweep through late tonight and early Thursday. Winds
will veer to west and northwest behind the front, possibly reaching
low end Small Craft Advisory criteria by Thursday afternoon and
evening.

&&

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

&&

$$

SYNOPSIS...Hitchcock/TMA
NEAR TERM...Hitchcock/TMA
SHORT TERM...Thomas
LONG TERM...JJR
AVIATION...Hitchcock/TMA
MARINE...Hitchcock/TMA