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577
FXUS61 KBUF 312242
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
642 PM EDT Fri May 31 2024

.SYNOPSIS...
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Dry weather will continue through Saturday as high pressure across
the region drifts to the east coast. Weakening low pressure will
move into the Ohio Valley late Saturday night and Sunday, bringing a
chance of a showers and a few thunderstorms, especially across
Western New York. Dry and warm weather will follow for early next
week.
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&&

.NEAR TERM /THROUGH SATURDAY/...
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Mid level ridge will slowly crest over the region through Saturday
as surface high pressure drifts to the east coast. This will
maintain fair weather across the region through Saturday. There will
be an increase in high clouds by later Saturday afternoon ahead of
an approaching shortwave trough, but these initial clouds will be
thin cirrus with plenty of sunshine still filtering through.

Good radiational cooling conditions expected tonight, but the
air mass will be a touch milder than last night, limiting
coverage potential of frost. Some patchy frost is still possible
in the coldest valleys of the Southern Tier and the coldest spots of
Lewis County. Overnight lows ranging from the upper 30s in the
coldest spots of the western Southern Tier and Lewis county with 40s
elsewhere. Modest warm advection and sunshine should boost
temperatures Saturday several degrees warmer than Friday`s readings
with most highs in the mid to upper 70s.
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&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
High pressure ridging at the surface and aloft will shift east from
the Great Lakes to New England Saturday night. In its wake, a
weakening shortwave will lift out of the Ohio Valley and towards the
forecast area. While this will result in a wealth of cloud cover for
the region, the vast majority of the night should remain rain free
save for a few showers possibly reaching the far western zones late
in the night. Otherwise, with limited radiational cooling, a warming
airmass and gentle southerly flow developing, it should be a notably
milder night with low temperatures some 10-15 degrees warmer
compared to the last few nights we`ve seen.

For Sunday, mid-range model guidance continues to converge towards a
solution that favors a more southern track and substantial weakening
of the aforementioned shortwave trough as it runs up against and
flattens the ridge to the east. Have tapered back PoPs to reflect
this trend, though areas in the Southern Tier (especially closer to
the NY/PA border) are still `likely` to see a few showers or even an
isolated tstorm Sunday. The precip and thicker cloud cover in this
area are expected to hold down daytime temps in the upper 60s to low
70s, while mid to upper 70s will be found further north where some
sunshine may peak out before day`s end.

With the loss of daytime heating and the return of strong high
pressure subsidence, any lingering showers should taper off or shift
out of the forecast area fairly quick Sunday evening. This stretch
of dry weather should then persist through Monday night before the
high again migrates well east of the region. This also continue the
warming trend, with highs Monday mainly in the upper 70s though a
few readings in the low 80s are expected across the Lake Plains.
Monday night will feature lows in the mid 50s to low 60s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Broad mid-level ridging over the Great Lakes and a deepening trough
over the Northern Plains will both gradually shift eastward through
the remainder of the week. This change in the overall jet stream
pattern will cause much warmer air to continue circulating into the
region, while also drawing additional GOMEX moisture northward into
the eastern CONUS. The increasing heat and humidity will result in
true summer-like weather Tuesday through Wednesday, with the mercury
climbing into the 80s across much of the region both days.
Increasing instability may also result in the formation of diurnal
showers and thunderstorms, though chances will be greater on
Wednesday as surface high pressure loses more of its influence over
the region and dewpoints climb into the 60s.

The trough will deepen and then close off across the Upper Midwest
by Thursday. This will cause widespread showers and likely a few
thunderstorms to push across the eastern Great Lakes region as the
system`s cold front and prefrontal trough move through the region
between Thursday and Friday. This should also bring about the
beginning of a cooling trend across the region, with high temps
expected to fall back into the low/mid 70s by the end of the week.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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VFR will prevail through Saturday. High pressure will drift east
across the Ohio Valley and eastern Great Lakes tonight through early
Saturday before reaching the east coast Saturday evening. Associated
dry air and subsidence will bring mainly clear skies through
Saturday morning, with a west to east increase in high cirrus level
clouds Saturday afternoon.

Outlook...

Sunday...VFR/MVFR with a chance of showers and possibly a few
thunderstorms, particularly across Western NY.
Monday and Tuesday...VFR.
Wednesday...Mainly VFR with a chance for showers.
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&&

.MARINE...
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Westerly winds to around 15 knots on Lake Ontario will produce a
moderate chop on the lake into this evening.

Relatively quiet weather this weekend into early next week with no
marine headlines expected. A weak low moves northeast from the Ohio
Valley to just south of the lower Great Lakes late Saturday night
through Sunday with a chance of a few showers and isolated
thunderstorms. High pressure will then build into the region Sunday
night through Monday.
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&&

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

&&

$$

SYNOPSIS...Apffel/Hitchcock/TMA
NEAR TERM...Hitchcock/TMA
SHORT TERM...PP
LONG TERM...PP
AVIATION...Hitchcock
MARINE...Hitchcock/TMA