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556
FXUS61 KBUF 290851
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
451 AM EDT Wed May 29 2024

.SYNOPSIS...
A secondary cold front will drop across the region today, sparking a
few showers across Western New York along and south of the New York
State Thruway. Behind this cold front skies will clear, allowing for
excellent radiational cooling conditions both for tonight as well as
tomorrow night...when temperatures drop into the low to mid 40s, and
upper 30s in the traditionally colder valleys of the Southern Tier
and possibly within the Tug Hill region. Dry weather for the end of
the week with day to day warming through the weekend.

&&

.NEAR TERM /THROUGH THURSDAY/...

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A secondary cold front is dropping southward across our region,
presently near Lake Ontario this early morning. Ahead of the front
still deep moisture is supporting a few spot showers this morning,
that will increase towards midday and early afternoon with
additional surface heating. Greatest coverage will be along and
south of the NYS Thruway today, with greater convective activity
likely to remain just south of the state line in closer
proximity to a shortwave cutting under our region within the
base of a long wave trough.

Instability is marginal, around 250 to 500 J/KG of MUCAPE, and mid
level lapse rates generally stay 6.5 C/KM or lower which will only
support limited thunder activity under the trough aloft.

As the secondary cold front drops southward today ceiling heights
will lift and clouds scatter out with a return to sunshine. Despite
the return to sunshine, a cool 850 hPa airmass of just 5-6C will
support highs only in the low to mid 60s today.

Skies will clear tonight, with river valley fog likely across the
Southern Tier. A light northerly, cold air advection flow will make
for a chilly night with lows in the lower to mid 40s, and upper 30s
across the traditionally colder inland Southern Tier.

Sunshine aplenty for Thursday with high pressure slowly edging
towards our region. Cold air advection lowering 850 hPa temperatures
to the low single digits will promote afternoon highs again in the
lower to mid 60s.
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&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
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...Gorgeous Weather Guaranteed As We Flip the Calendar to June...

I really don`t think that you can script the weather to be any
better than it will be during this period...as unseasonably cool
weather will give way to a welcomed warming trend that will include
wall to wall sunshine and temperatures that will return to above
normal levels.

An unusually deep trough for this time of year will exit the Lower
Great Lakes and New England Thursday night and Friday...while a
progressive shortwave ridge and its associated areas of sfc high
pressure will approach our region from the Upper Great Lakes. This
in concert with a dry airmass will assure that we will have starlit
skies Thursday night with plenty of sunshine on Friday.

The aforementioned mid level ridge will pass over our forecast area
Friday night and Saturday...while the area of high pressure will
settle over the Carolinas. This scenario will only enhance an
ongoing warm advection pattern that will support day to day warming.
By Saturday afternoon...we will be enjoying temperatures that will
be in the mid to upper 70s...a few degrees above normal.

Clouds will move across the region Saturday night...as the passing
ridge will give way to a fast moving shortwave that will be
approaching from the mid western states. While >90% of the region
should remain rainfree Saturday night...a late night shower cannot
be ruled out over the far western counties near Lake Erie...and
particularly across Chautauqua county.

The only other possible blemish on the weather could be the chilly
conditions at the open of this period. Light winds and mainly clear
skies Thursday night will allow the mercury to fall into the 40s...
with readings in the mid to upper 30s fully expected across the
Southern Tier and in the foothills to the Adirondacks. Those camping
Thursday night should plan accordingly...and yes...its not out of
the question that the colder valleys of the Srn Tier experience
patchy frost.
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&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
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There is high confidence that we will experience ABOVE normal
temperatures through this period...and while there will be the
potential for some showers...the BULK of the time will be RAINFREE.

A zonal flow will be in place across the country on Sunday...while
sfc based ridging will be centered along the Southeast coast. This
will maintain a modest southwest flow of warm air into our region
with temperatures climbing to between 75 and 80. Again...while
mainly dry weather is expected...a shortwave passing just to our
south could support scattered showers and isolated thunderstorms...
mainly across the Srn Tier.

A weak amplification in the otherwise zonal upper level flow will
direct a subtle ridge over the Lower Great Lakes Sunday night and
Monday. This will favor fair dry weather...although diurnally driven
shower activity/isolated tstorms will be possible across the Srn
Tier.

There is relatively low confidence in the overall pattern for
Tuesday...as the next shortwave could push a cold front through the
area. This would support scattered showers...and possibly some
thunderstorms...but will hold off on inserting the latter for now
due to the uncertainty expressed in the guidance. In any case...
Tuesday should be a warm and humid day with forecast max temps found
well in the 80s with Td`s ranging from 60 to 65.
-- End Changed Discussion --

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
For the 06Z TAFS, a secondary cold front will drop across the region
today, sparking a few showers across WNY south of the NYS Thruway.

While ceiling heights will largely lower to MVFR in the deeper
moisture ahead of the front this morning, higher terrain of the
Southern Tier, including KJHW will likely drop to IFR. Some patchy
fog is possible near KIAG before sunrise, but confidence is low as
MVFR clouds aloft may keep this fog from forming.

Behind this cold front, a much drier airmass will scatter out clouds
with all areas VFR by late afternoon.

High pressure slowly nosing its way eastward will bring clear skies,
light winds and VFR flight conditions tonight.

Outlook...

Thursday through Saturday...VFR.
Sunday...Mainly VFR with a slight chance for showers.

&&

.MARINE...
Ahead of an area of surface high pressure slowly building eastward
today will continue a light northerly flow on the Lakes today and
into Thursday morning, with a modest chop along the south shorelines
of the Lakes.

Winds will back to westerly later Thursday...and eventually become
light and variable by Saturday morning as the surface high crests
over the Lakes.

&&

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

&&

$$

SYNOPSIS...Thomas
NEAR TERM...Thomas
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...Thomas
MARINE...Thomas