064
FXUS61 KBUF 171821
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
221 PM EDT Wed Jul 17 2024

.SYNOPSIS...
There will be showers and a few thunderstorms with a cold
frontal passage this afternoon into early this evening. Much
drier air will build in behind the front, resulting in more
comfortable humidity levels. High pressure will build in behind
the front, resulting in fair weather Thursday through at least
Saturday.

&&

.NEAR TERM /THROUGH THURSDAY/...
A cold front draped across the region early this afternoon will
continue to push southeastward through this evening. Cloud
cover has limited instability today, but LAPS shows CAPE 500 to
1000 J/Kg across the Southern Tier. With the approaching front
and some instability this will generate showers and
thunderstorms across the Western Southern Tier. Radar shows
these developing, with mesoscale guidance bringing these into
the Southern Tier between 2 and 5 p.m. this afternoon. PWAT
values still around 1.75 inches ahead of the front, so some
heavy downpours and localized flooding cannot be ruled out
there.

Otherwise, the mid-level trough will move across the region
tonight, and this will usher in a cooler and drier air mass.
Can`t rule out a stray shower with this trough this evening,
before the drier air mass wins out later tonight. The light
winds and partial clearing will allow for fairly good
radiational cooling, and possibly some river valley fog in the
Southern Tier. Lows will mainly be in the mid to upper 50s.

On Thursday surface high pressure will be centered near Iowa,
with the mid level trough axis still across our region. The air
mass should be too dry to support much precipitation, but
isolated showers can`t completely be ruled out along with some
strato-cumulus cloud cover. It will be notably cooler and more
comfortable with highs will be in the lower to mid 70s.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
Any remaining lingering showers will wrap up Thursday evening,then
gradual clearing skies will likely take place. This will support
good radiational cooling overnight, with the cooler spots found in
the upper 40s and a range of 50s elsewhere.

A spectacular finish to the work week is on tap for Friday and dry
with low humidity levels. Highs on Friday will generally be found in
the 70s.

As we progress into the weekend a gradual day to day warming trend
is advertised to take place. Other than that, high pressure anchored
over the Great Lakes and Ohio Valley will likely keep much of the
region dry. That said...there is a weakening front approaching from
the north late Saturday afternoon and Saturday night. This feature
may introduce a shower or isolated thunderstorm across the St.
Lawrence Valley and North Country by Saturday night. Have kept very
low end chance PoPs for now for the above locales. Otherwise...highs
on Saturday will be found in the upper 70s to low/mid 80s.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Mid-level low pressure centered over Quebec, Canada will amplify
Sunday as a shortwave trough rounds its base. At the surface, high
pressure spread across the area Saturday will remain mostly in place
Sunday, however a backdoor cold front will slide southeast across
New York state. This front looks to be moisture starved, and
therefore a low chance for a few spotty showers. In the wake of this
front, surface high pressure will re-establish itself across the
lower Great Lakes for the start of the week, continuing dry weather
Monday and Monday night.

Uncertainty remains for Tuesday and Wednesday with a broad, weak
trough over the Plains moving slowly east into the Mississippi
Valley. This will support a diffuse area of moisture and general low
pressure drifting northeast across the Ohio Valley. Depending on the
northward extent of the moisture Tuesday, chances for showers will
be possible, and remain likely south of the forecast area. As the
moisture further creeps northward Wednesday, the chances for showers
will continue.

Otherwise, temperatures will warm this weekend with highs slightly
above average for the end of the weekend and the start of next week.
Highs will range in the low to mid 80s.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
A cold front across the region early this afternoon will
continue to push southeastward through this evening. This will
mainly generate showers and a few thunderstorms ahead of the
boundary, with only light showers possible behind it.
Thunderstorms may impact KJHW this afternoon, but otherwise
expect mainly VFR flight conditions at our TAF sites.

Mainly rain-free and VFR flight conditions tonight and Thursday.
There`s a risk that river valley fog will bring IFR or lower
visibility at KJHW, with a non-zero risk for fog elsewhere.
There may be patchy MVFR cigs tonight and Thursday.

Outlook...

Thursday night through Monday...VFR.

&&

.MARINE...
A cold front will push south of the lakes through this evening.
Northwesterly winds will increase to 10 to 20 knots on Lake
Ontario, which will approach small craft advisory criteria
along the south shores of Lake Ontario. For now, expected
conditions fall just short of criteria. High pressure will then
build across the Lakes later tonight through the end of the work
week with a light wind flow.

&&

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

&&

$$

SYNOPSIS...Apffel/Thomas
NEAR TERM...Apffel
SHORT TERM...AR
LONG TERM...EAJ
AVIATION...Apffel
MARINE...Apffel