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893
FXUS61 KBUF 220812
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
412 AM EDT Sat Jun 22 2024

.SYNOPSIS...
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More comfortable conditions are on the horizon however, we`ll have
to endure a couple of more days of warm and humid weather.  Unlike
the days earlier this week with dangerously high heat indices, an
oscillating frontal boundary will support enough cloud cover and
thunderstorm activity to dampen the heat. However with these
thunderstorms, there will be the risk of torrential downpours and
severe weather.
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.NEAR TERM /THROUGH TONIGHT/...
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Currently a warm front lies across the southern portions of Lake
Ontario, creating a split in the cloud cover. This boundary acts as
a split between the cloud cover and spotty showers to the north and
dry weather to the south. Additionally, some fog has formed across
the Genesee Valley and Southern Tier in the wake of the afternoon
storms. These conditions will persist through the rest of the night.
Temperatures tonight will continue to remain of the warmer side with
lows in the upper 60s to low 70s.

The warm front will continue to waver across the northern portions
of New York State today, supporting plenty of instability for
showers and thunderstorms to form again late this morning and
afternoon. Favored regions of lake breeze boundaries and in close
proximity to the frontal boundary. Places northeast of Lake Erie
across southeastern Erie and eastern Chautauqua counties will have
the lowest chances for storms. Temperatures today will continue to
be warm, especially south of the boundary. Highs will range in the
low to mid 80s across areas south of Lake Ontario, whereas areas
east of Lake Ontario will see highs in the mid to upper 70s.

Tonight, the surface low parent to the warm front will strengthen
across the central Great Lakes and lift the warm front north of the
region. This will then place the area beneath the warm sector,
supporting ample warm moist air advection. Overall this will
continue the chances for showers and thunderstorms, with the best
likelihood for activity lying across the North Country due to the
close proximity to the front.
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&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
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A mid-level shortwave rippling through the zonal flow aloft and
corresponding surface reflection (997-999mb low) passing to our west
and northwest, will drag a cold front through the Lower Lakes on
Sunday. Associated height falls with the pre-frontal trough will
`likely` encourage some measure of shower and thunderstorm activity
ahead of this cold front. Guidance continues to suggest that the pre-
frontal trough will arrive before the occurrence of peak heating
between 12Z-15Z for far WNY. Even so...the cold front may still
spark additional storms as it rolls east through the forecast area
in the afternoon. Right now...the best chance for organized storms
looks to be from the S. Tier/western Finger Lakes region ENE into
the North Country and St. Lawrence Valley. Given ample shear (0-6km,
40 knots) any of the stronger cells will `likely` have the potential
to produce damaging winds and even an isolated tornado. SPC has
highlighted the above mentioned areas in a slight risk for severe
weather. Lastly...storms will also be capable of producing
torrential rainfall given PW values in the neighborhood of 1.75-2.00
inches.

Otherwise...outside of the convective activity it will become quite
breezy, with wind gusts up to 45 mph. The strongest winds will be
felt northeast of Lake Erie across the Niagara Frontier. Highs on
Sunday will range from the upper 70s across the higher terrain to
the low/mid 80s elsewhere.

Sunday night...with the departure of the cold front showers and
thunderstorms will quickly decrease in coverage. However...there may
still be some showers that linger east of Lake Ontario/St. Lawrence
valley.

High pressure begins to build in on Monday with increasing
subsidence which will bring about mainly dry weather for most
locales. Although an isolated shower still can`t be ruled out,
especially east of Lake Ontario. The best part will be the notably
cooler airmass and less humidity. Highs on Monday will be in the 70s
near 80F in spots.

Surface high pressure slides overhead Monday night and then begins
to sink south towards the Mid-Atlantic on Tuesday ahead of the next
cold front. We should see mainly dry weather Tuesday before chances
for showers and storms increase through Wednesday. More on that in
the long term disco.
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&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
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Confidence is low in timing and coverage of showers/thunderstorms
associated with an approaching front for Tuesday night and Wednesday.
Long range guidance is in poor agreement on the evolution of a
shortwave expected to slide east across Southern Ontario and the
Great Lakes. Greater chances for showers and thunderstorms will
potentially arrive Wednesday as a ~982mb surface low tracks across
northern Quebec, sending its elongated cold front through the
Northeast. While timing of this front and its associated prefrontal
trough remain in question and thus lend lower confidence in how
convection will ultimately unfold Wednesday...The system is expected
to tap into a deeper plume of GOMEX-based moisture with PWATs
potentially climbing to near 2" as it approaches. Thus, any storms
that develop and move through the region should have the potential
to bring locally heavy rains.

The primary cold front should move through the region Wednesday
night, with increasing subsidence and a drier airmass allowing
shower/thunderstorm chances to decrease from west to east in its
wake. As much of the Northeast sits within the post-frontal airmass,
temperatures will be notably cooler Thursday and Thursday night,
with highs in the low/mid 70s and lows in the 50s and upper 40s
respectively. Dry weather should then last through the end of the
week with moderating temperatures as surface high pressure moves
over and east of the region.
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&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
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With a warm front lying across the southern portions of Lake
Ontario, dry conditions lie to the south, whereas a few showers and
clouds are spread across the North Country. While conditions across
the area remain VFR across all TAF sites, conditions will diminish
throughout the day.

Today, the warm front will waver northward. While CIGS today will
gradually become MVFR today, the main impact will be the threat for
convection, particularly east of Lake Ontario and along lake breeze
boundaries. Chances for showers and thunderstorms will then continue
throughout tonight inland from the lakes.


Outlook...

Sunday...VFR/MVFR. Showers and thunderstorms likely.
Monday...Mainly VFR. A chance for afternoon and evening
thunderstorms inland from the lakes.
Tuesday...Mainly VFR conditions expected.
Tuesday night and Wednesday...MVFR/VFR with a chance for showers and
thunderstorms.
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&&

.MARINE...
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Light winds and minimal wave action is expected to continue across
the lower lakes today. There will still be the chance of afternoon
showers and thunderstorms which could produce gusty winds and higher
wave action.

A cold front will approach the region Sunday with increasing southwest
winds which may bring a period of SCAs to area lakes. Northerly
flow behind the front will then bring continued choppy conditions
to the lakes through Monday. High pressure builds in late Monday with
diminishing winds and waves for Tuesday.
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&&

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

&&

$$

SYNOPSIS...EAJ
NEAR TERM...EAJ
SHORT TERM...AR
LONG TERM...AR/PP
AVIATION...EAJ
MARINE...AR/EAJ/Thomas