196
FXUS61 KBUF 210846
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
446 AM EDT Tue May 21 2024

.SYNOPSIS...
Mid-summer warmth will be upon the Lower Lakes today with well above
normal temperatures and elevated humidity levels. With the mild
conditions and humidity today it will also support some showers and
thunderstorm well inland from the lakes. A greater threat for
showers and storms arrives Wednesday as a cold front approaches the
region. Cooler more comfortable weather can be expected Thursday
into the first part of the Memorial Day weekend. Unsettle weather
then makes a return on Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
The main complex of showers and storms associated with the
convectively enhance shortwave tracking across Lake Huron will
largely stay to the north western New York. There will be a few
showers that work across the open waters of Lake Ontario this
morning, which will then potentially impact areas east of Lake
Ontario later on, especially across the St. Lawrence River
valley. This is captured fairly well by hi-res guidance.

Otherwise...mid-summer warmth will be upon us today with
temperatures more typical of July than late May. Highs today will
once again soar into the mid to upper 80s. We even potentially could
hit the 90F in a few locales, especially in the Genesee Valley.
There will also be some showers and storms to contend with again as
the shortwave mentioned early passes to our north this afternoon.
Similar to yesterday....the best shot to see a shower or storm will
be found well inland from the cooler stable lakes, especially from
the Southern Tier northeast across the Finger Lakes into the North
Country.

Tonight...with the loss of daytime heating most showers and storms
will fall apart with dry weather expected across the region. Muggy
(dwpts in the 60s) and mild night with mercury reading found in the
mid to upper 60s by sunrise.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Well within the warm sector of a system tracking across the Great
Lakes, Wednesday will be another warm day with increasing humidity.
Out ahead of an approaching cold front, a pre-frontal trough will
push across the forecast area from around lunchtime through the
early evening hours. CAPE values for Wednesday afternoon approaching
2,000 J/kg, especially south of Lake Ontario. Instability levels
combined with the trough will result in showers and thunderstorms
across the area, especially inland from the lakes. The Storm
Prediction Center does have most of the area under a `Slight Risk`
for severe thunderstorms on Wednesday. With instability across the
area, showers/thunderstorms will be possible ahead of the trough as
well as daytime heating increases through the morning. Large scale
shear values seem to be a bit on the lower side with guidance
suggesting less than 30 knots of shear during the peak, HOWEVER, a
remnant Mesoscale Convective Vortex (MCV) will be tracking
into/across the area, and these system tend to have increased shear
within the system itself that modeling has a hard time to pick up on
sometimes. Luckily this is a decaying MCV that should hopefully
limit the severe potential vs a more organized system. DCAPE values
nearing 750 J/kg will support the potential for strong wind gusts.
Temperatures on the day will warm to the lower 80s over the higher
terrain to near 90 for the lower elevations.

Wednesday night, showers and some thunderstorms will linger into the
mid-evening  hours over the eastern portions of the area as the
trough is exiting the region. There should be a break in the showers
for most of the night ahead of the cold front. With daytime heating
not in play, instability levels will lower overnight. As the cold
front crosses the region during the second half of the night and
toward daybreak on Thursday some showers will be possible,
especially inland from the lakes. There may be just enough lingering
instability along with forcing from the front to cause a few
thunderstorms. Shear values do increase some with the frontal
passage, but not expecting much in the way of thunderstorm
potential. Low temperatures on Wednesday night will drop to the low
to mid 60s.

Thursday and Thursday night, some showers will linger into the
morning, mainly for the eastern third of the area. Clouds will
decrease from northwest to southeast behind the departing cold front
and as drier air moves into the region. A cooler day on Thursday
with afternoon highs mainly in the upper 60s to upper 70s from the
higher terrain to the lower elevations respectively. Thursday night,
lows will dip down to the low to mid 50s across the entire area.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Dry conditions to start the period before a trough and sfc low track
across the Ohio Valley and Great Lakes. A warm front tracking toward
the region out ahead of the sfc low will start to increase showers
potential for Friday night. Showers continue through Saturday night
as a few disturbances track northeast around a weak trough over the
Great Lakes.

Fair conditions expected for Sunday as high pressure tracks across
the region.

The next round of showers approaches late Sunday night/Monday
morning as another trough and sfc low track across the region.

Temperatures for the period will be in the low to upper 70s for most
of the area with the cooler temperatures across the higher terrain
and the warmer temperatures over the lower elevations.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
There is a low end chance of a shower or storm as a convectively
enhanced shortwave approaches and then begins to pass to our north
overnight into this morning. If a shower or storm did make it into
our region tied to the shortwave it would only briefly impact KIAG or
KROC. Otherwise...most terminals will continue to see VFR.

VFR and light winds will continue today, there will be some
afternoon and evening storms across the Southern Tier, Finger Lakes,
and then northeast into the North Country.

Outlook...

Wednesday...VFR/MVFR. Showers and thunderstorms likely.
Thursday...Mainly VFR. A chance of showers.
Friday and Saturday...Mainly VFR.

&&

.MARINE...
Light winds with minimal wave action expected on Lake Erie and Lake
Ontario overnight. There will also be a low end chance of a shower
or thunderstorm as a weak wave approaches and then begins to pass to
the north of Lake Ontario.

South winds develop and pick up a bit today as a cold front to our
west begins to approach the eastern Great Lakes, but conditions will
remain below small craft levels. Low pressure will sends a cold
front into the eastern Great Lakes on Wednesday but winds and waves
look like it will remain below small craft conditions for the rest of
the week.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...SW
LONG TERM...SW
AVIATION...AR
MARINE...AR