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816
FXUS61 KBUF 220239
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1039 PM EDT Tue May 21 2024

.SYNOPSIS...
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There will be showers and thunderstorms as a cold front
approaches the region on Wednesday. Some of these storms may be
strong with gusty winds possible. Cooler more comfortable
weather can be expected Thursday into the first part of the
Memorial Day weekend.
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&&

.NEAR TERM /UNTIL 6 PM WEDNESDAY EVENING/...
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Late this evening a mid-level wave will exit to the east and
with diminishing instability following nightfall it will be dry
and mild overnight with lows in the 60s.

Active weather day expected Wednesday with the potential for strong
to severe thunderstorms. Ahead of approaching cold frontal boundary
an increasingly unstable environment will emerge, with surface
temperatures in the mid to upper 80s and surface dewpoints getting
into the mid to upper 60s. Surface based CAPES likely nearing 2000
j/kg during peak heating. Increasing shear profiles suggesting the
potential for damaging winds and hail, with even a small corridor of
enhanced low level helicity developing into southwest New York
possibly favoring a few rotating cells. HRRR and most mesoscale
guidance brings this into Western NY around 1 p.m. then moves
the line of storm eastward to the eastern Lake Ontario region
around 6 p.m. A secondary line of less developed storms is
possible just ahead of the cold front heading into Wednesday
evening. SPC has most of the area in a slight risk for severe
weather, with the exception of portions of the Eastern Lake
Ontario region which is in a marginal risk.
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&&

.SHORT TERM /6 PM WEDNESDAY EVENING THROUGH FRIDAY/...
Closed mid-level low centered over the central portions of the
Ontario province will become vertically stacked by Wednesday night
with its surface low. As this low pressure system weakens, its
associated cold front draped southward across the lower Great Lakes
will continue to progress eastward across western and north central
NY. This being said heading into Wednesday night, showers and a few
thunderstorms will linger into the evening hours, though the
potential for severe thunderstorms will diminish shortly after
sunset due to the loss in diurnal heating and instability. The front
will then cross Wednesday night and continue to support showers
inland from the lakes. By Thursday morning the vast majority of
shower activity should be to the southeast of the area, as dry air
from the next incoming surface high advances east towards the area
resulting in dry conditions across the region.

As surface high pressure pushes east across the area Thursday
through Friday, associated subsidence will support dry weather
persist. Though dry, it will be `cooler` in the wake of the cold
front Thursday and Friday with highs ranging in the 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
The next mid-level trough over the northern Plains/Upper Midwest
will support a surface low to push northeast across the eastern
Great Lakes into southern Canada Saturday. This will support a warm
front to advance towards the region ahead of the surface low,
resulting in an increase in shower potential Friday night and last
through Saturday night.

A brief interlude in shower activity for the Memorial Day weekend on
Sunday as high pressure slides east across the region.

Showers return late Sunday night and linger through Monday as
another upper level trough and associated surface low pushes across
the Ohio Valley towards the lower Great Lakes.

Temperatures for the period will be near normal with high
temperatures ranging in the low to upper 70s for most of the area
and cooler temperatures across the higher terrain.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
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VFR with no active weather through 15Z Wednesday. Showers and
thunderstorms will move into the area ahead of a cold front
Wednesday afternoon. Some of these could be strong with gusty
winds and hail. After this, another line of storms is possible
with the cold frontal passage Wednesday evening, however these
are not expected to be as strong.

Outlook...

Wednesday night...VFR/MVFR. A chance of showers and thunderstorms.
Thursday...Mainly VFR. A chance of showers.
Friday...Mainly VFR.
Saturday...Restrictions possible. A chance of showers and
thunderstorms.
Sunday...Mainly VFR. A chance of showers and thunderstorms.
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&&

.MARINE...
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Low pressure will send a cold front into the eastern Great
Lakes on Wednesday, resulting in a increasing SSW flow. But
winds and waves look like they will remain below small craft
conditions with this frontal passage and for the rest of the
work week.
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&&

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

&&

$$

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