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496
FXUS61 KBUF 091750
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
150 PM EDT Sun Jun 9 2024

.SYNOPSIS...
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An upper level trough will move through the area, producing
widespread showers and scattered thunderstorms through early
evening. Scattered showers and cool temperatures will continue
tonight through Monday. High pressure will then build in, resulting
in a drying and warming trend through Thursday.
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&&

.NEAR TERM /THROUGH MONDAY/...
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Early this afternoon, showers and a few thunderstorms are
developing across the region. This is due to diurnal
instability, combined with a compact shortwave which is
rotating through longwave trough and dropping southward across
the region. Initially showers/storms are developing along a
convergence zone from the Niagara Frontier east across the
Genesee Valley and Northern Finger Lakes, and along a boundary
across the Saint Lawrence Valley. Mesoscale guidance in good
agreement showing the area of showers expanding and dropping
southward, following the progression of the shortwave.

Model agreement and upstream radar trends provide high
confidence in the development of showers which should have quite
a bit of areal coverage. These will hold off until closer to
sunset across the Southern Tier due to the north to south
movement. While severe thunderstorms are unlikely, low freezing
levels around 7k feet on the Buffalo 12Z sounding suggest a risk for
small hail with any thunderstorms. Gusty winds can`t completely be
ruled out either, but for the most part these won`t be much stronger
than the 25 to 35 mph winds outside of the storms.

Showers will decrease in coverage from northwest to southeast this
evening as the vorticity maxima moves southeast of the area.
Overnight, additional weaker shortwaves, deepening moisture, and
even some lake induced instability will support a few more scattered
showers, increasing in coverage towards Monday morning.

A cool northwest flow with 850mb temperatures falling to +3C on
Monday will result in the coolest day of the recent stretch of
unsettled weather. Highs will mainly be in the upper 50s to lower
60s. Cyclonic flow aloft will result in lots of cloud cover and
possibly a few showers although coverage will be limited.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
An upper level trough over the Northeast will become elongated down
to the central Appalachians Monday through Tuesday. An upper level
ridge will nose into the Great Lakes region Tuesday night while a
shortwave trough moves across the Mid-Atlantic region. The ridge
will flatten out across the forecast area into Wednesday.

Cool, northwest flow with 850mb temperatures falling to +3C will
result in the coolest day of the recent stretch of unsettled weather
on Monday. Highs will reach the low to mid 60s across the lower
elevations and upper 50s to near 60 across the higher terrain. A
500mb trough axis and deep layer moisture will move across the
forecast area Monday. The cooler airmass may create lake induced
instability and scattered to numerous rain showers will track from
the Lakes to inland areas, with showers lingering the longest across
southeast portions of the forecast area Monday.

Showers will come to an end Monday evening. The upper level trough
will remain across the region through Tuesday night. Drier air and
low level subsidence will be increasing across the region, however
mostly cloudy conditions will persist most of the time. Tuesday will
begin the warming trend across the region with highs in the upper
60s to low 70s, mid to upper 60s across the higher terrain. Finally,
the elongated trough will move east of the region Wednesday. This
will promote dry and warmer weather with highs in the mid to upper
70s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A trough will deepen across the Great Lakes region as an upper level
ridge builds across the Rockies late in the work week. A strong,
southerly flow will promote warm weather Thursday through Friday. An
area of low pressure is expected to track across northern Ontario
and Quebec Thursday through Friday with a cold front impacting the
region during this time. There is low confidence in the timing of
the front, however this should bring a period of scattered showers
and thunderstorms. An area of high pressure is expected to move into
the region this weekend with medium confidence of dry, fair
weather.

Temperatures will begin above normal mid-week and fall to near
normal for the weekend.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A mid level trough will move southeast across the area, and
combine with modest daytime instability and lake/terrain
generated low level convergence boundaries to generate another
area of showers and scattered thunderstorms crossing the area
from north to south. Expect areas of MVFR CIGS/VSBY to develop,
with local/brief IFR in thunderstorms. Thunderstorms may
produce some small hail.

The more organized showers and scattered thunderstorms will taper
off this evening, although a few scattered showers may linger
overnight. CIGS/VSBY should improve back to VFR initially in the
evening, but areas of MVFR CIGS will likely develop overnight in
stratus. This stratus will linger most of the day Monday, with
MVFR cigs lasting into the afternoon hours at most locations.

Outlook...

Monday night through Thursday...Mainly VFR.
Friday...VFR/MVFR. A chance of showers and thunderstorms.

&&

.MARINE...
Moderate westerly winds today, with another round of Small
Craft Advisory conditions on both lakes. Winds will decrease on
Lake Erie this evening, but Small Craft Advisory conditions will
continue much of tonight on Lake Ontario. Winds will be
somewhat lower Monday, but still expect choppy conditions on
both lakes.

More favorable winds and waves for boating will return by the middle
of the week.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement through Monday morning for NYZ004.
     Beach Hazards Statement through Monday morning for NYZ005>007.
     Beach Hazards Statement until 11 PM EDT this evening for
     NYZ010-019-085.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LEZ020.
         Small Craft Advisory until 11 PM EDT this evening for
         LEZ040-041.
         Small Craft Advisory until 5 AM EDT Monday for LOZ042.
         Small Craft Advisory until 11 AM EDT Monday for LOZ043>045.

&&

$$

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