693
FXUS61 KBUF 081417
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1017 AM EDT Wed May 8 2024

.SYNOPSIS...
Dry weather will then prevail most of the time for the rest of
today, although a few more showers and thunderstorms are
possible later in the afternoon and evening, especially east of
Lake Ontario. Unsettled weather will then last Thursday through
the weekend with a series of low pressure systems crossing the
region.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Steady showers along a warm frontal boundary has exited our
forecast area to the north and east late this morning.
Meanwhile, a 40 knot westerly flow at 850mb has mixed out the
remaining low moisture across the rest of Western NY resulting
in sunny skies late this morning. The dry weather will hold
through early afternoon, with warm and breezy conditions with
wind gusts to 40 mph.

A secondary shortwave trough will move across northern NY this
afternoon. Another round of showers and thunderstorms are
possible mainly east of Lake Ontario but also along a
convergence zone south of Lake Ontario. Most of the region will
be post-frontal with low chances of thunderstorms, however
greater instability will be just to the southeast of the
forecast area and coupled with a strong wind field, there may be
a few stronger storms late this afternoon into this evening. A
few showers or storms are also possible along a convergence
boundary south of Lake Ontario late afternoon and early evening.

The shortwave trough will move east of the region tonight and
showers and any thunderstorms will diminish and move east of the
region. Dry conditions are expected across the forecast
area overnight.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
An elongated mid level trough will remain in place Thursday through
Thursday night from the Canadian Maritimes to the Great Lakes, with
an east-west oriented frontal zone stretching from the Ohio Valley
to the Mid Atlantic. Latest model guidance has continued the
southward trend in the frontal position, with a wave of low pressure
moving east along the boundary now taking a farther south track
Thursday through Thursday night. The farther south track will yield
a much improved forecast for Thursday, with mainly dry weather
expected through at least the first half of the day. Deeper moisture
and frontogenesis will gradually increase from southwest to
northeast as the frontal wave moves across PA, bringing increasing
chances of showers in the afternoon for areas south of Lake Ontario.

Rain chances will continue Thursday night as another wave of low
pressure moves east along the front. The best chance of more
widespread rain will be found from the Southern Tier into Central NY
in closer proximity to deeper moisture and forcing, with rain
chances trending lower for areas close to the Canadian border.

Friday through Friday night, the longwave trough will continue to
carve out over the eastern US as a series of shortwaves dig through
the Great Lakes and New England. DPVA and height falls will maintain
an area of forcing and rain downstream of the trough axis, with a
weak surface low developing in response to the forcing aloft over PA
and the Mid Atlantic. The GFS continues to be the farthest north
with this feature and would produce widespread rain across the
region. The NAM/GEM/ECMWF have all trended farther southeast,
keeping the best chance of organized rain from the Finger Lakes into
Central and Eastern NY, with lower rain chances in our region.
Trended POPS and QPF down for Friday through Friday night,
especially for areas near the Canadian border.

Temperatures will be notably cooler Thursday through Friday as
persistent low level northeast flow funnels cooler air out of
Canada.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Overall, the pattern will remain unsettled over the weekend through
early next week, although the finer synoptic scale day to day
details remain uncertain. A deep mid level trough from the Great
Lakes to New England over the weekend will gradually deamplify
early next week, although shortwaves will continue to traverse the
US/Canadian border.

Saturday should start mainly dry, with one system moving east off
the New England coast and the next moving through the central Great
Lakes. The upstream shortwave and associated surface low will then
move over or just south of the region Saturday afternoon through
Saturday night, with another round of showers. The trough axis will
gradually move off the New England coast Sunday, with rain chances
trending down from west to east. Temperatures will remain quite cool
over the weekend with clouds and cool temperatures aloft. Highs both
days will reach the 55-60 degree range in most areas.

Monday through Tuesday another shortwave will move from the Great
Lakes into New England, maintaining a chance of a few showers.
Temperatures aloft will start to recover as mid level heights
gradually rise, allowing temperatures to trend to near or a little
above average by Tuesday.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR flight conditions for western NY, with lingering MVFR cigs
east of Lake Ontario. Winds will ramp up and southwest winds
15-25kts with gusts up to 30kts are possible late this morning
through early this afternoon from KIAG to KROC. Another round of
showers and a few thunderstorms are possible east- southeast of
Lake Ontario this afternoon into the evening. Flight conditions
will worsen from north to south tonight with MVFR/IFR
conditions at KART by 00z and at KROC/KBUF by 6z tonight.

Outlook...

Thursday and Friday...Mainly MVFR. Showers likely and MVFR stratus.

Saturday and Sunday...VFR/MVFR. A chance of showers.

&&

.MARINE...
WSW winds will then increase today, particularly across Lake
Erie...where winds and wave action will be sufficient to support
Small Craft Advisories as outlined below. Elsewhere choppy...but sub-
advisory conditions can be expected.

An increasingly moist airmass crossing the cold lake waters will
likely produce marine layer fog this morning on Lake Erie and Lake
Ontario with visibility restrictions.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LEZ020.
         Small Craft Advisory until 11 PM EDT this evening for
         LEZ040-041.

&&

$$

SYNOPSIS...Apffel/HSK
NEAR TERM...Apffel/HSK
SHORT TERM...Hitchcock
LONG TERM...Hitchcock
AVIATION...HSK/Apffel
MARINE...Apffel/HSK/JJR