925
FXUS61 KBUF 082223
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
623 PM EDT Wed May 8 2024

.SYNOPSIS...
Lingering showers will wind down through the evening east of Lake
Ontario, otherwise dry weather returns later tonight, then it`ll be
an unsettled weather pattern Thursday through the weekend with a
series of low pressure systems crossing the region.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
Winds will continue to come down with breezy conditions lasting
through early to mid evening. Dry weather is found from the Finger
Lakes westward early this evening. However, final shortwave now
moving across eastern Lake Ontario will keep lingering showers going
there into this evening, with dry weather returning for the entire
area later tonight.

The shortwave trough will move east of the region tonight with
lingering showers ending by midnight. Associated cold front will
move across the area resulting in mostly cloudy skies however rain-
free conditions will prevail for the rest of the night. Overnight
lows will range through the 40s.

Latest guidance is slower and further south with a convectively
augmented wave of low pressure on Thursday. It now appears it will
remain rain-free Thursday morning, with increasing chances for
showers across western New York late Thursday afternoon. Some
showers will likely move across the area Thursday night, but these
will be weaker producing nominal rainfall amounts. This also will
leave our area firmly in a stable northeast surface flow, with
little to no risk for thunderstorms. Following this, Thursday will
be a much cooler day with highs ranging from the mid 50s to lower
60s.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
High confidence for BELOW normal temperatures during this period...
particularly by day when the mercury is only forecast to reach into
the upper 50s to near 60. That will be a solid 5 to 8 degrees below
mid May normals. Meanwhile...it will generally be unsettled with
perturbations in the mean longwave trough supporting some showers
and thunderstorms. As for the details...

A shortwave will drive across the Lower Great Lakes on Friday...as a
wavy sfc frontal boundary will stretch across the Tennessee valley to
the Mid Atlantic region. The resulting DPVA and minimal height falls
will couple with a deep cyclonic flow and wealth of moisture to
warrant chc to likely pops over the far western counties and cat
pops over the Finger Lakes region and portions of the Srn Tier
where a change will be made in the wording from showers to rain.
There could be several hours of widespread/steady rain for that
area. Finally...H5 temps of -20c will enhance the instability
aloft...the mid levels will be stable enough to preclude the risk
for thunder.

A weak shortwave ridge will scoot across the forecast area Friday
night. While spotty showers may persist east of Lake Ontario...this
scenario will bring an end to the pcpn over the western counties.

Saturday...another robust shortwave will drop through the longwave
trough and pass just to the west and south of our forecast area...
along with a loosely organized sfc reflection. Unlike the previous
shortwave passage the day before (Friday)...this will focus the
associated forcing over the western counties. Will raise pops for
the Srn Tier to categorical...but being largely convective (H5 ~
-24c)...will maintain the wording of showers. The mid levels will be
more unstable as well...so will add slgt/chc wording for tstorms for
the western counties. Given the mean trough axis will cross the
region Saturday night...will maintain at least chc pops for showers.

A nominal 70kt H5 jetlet will dig into the base of the
aforementioned longwave trough over the region on Sunday and
encourage it to close off across New England. The slow exit of the
trough will keep at least scattered showers in place...particularly
over the Finger Lakes and Eastern Lake Ontario regions. Low single
digit H85 temps will keep the cool weather in place with the mercury
struggling to make it out of the 50s.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
A closed low and associated deep longwave trough centered in the
vcnty of Hudson Bay at the start of this period will rotate out
across Quebec during the course of the week. This will result in
height rises across the Lower Great Lakes that will lead to
temperatures finally returning to ABOVE normal levels.

While this general pattern will favor fair weather for the majority
of the period...another shortwave will push a cold front through the
region later Monday and Monday night. This will result in scattered
showers and a minimal risk for thunderstorms.

Dry weather should prevail with a passing shortwave ridge Tuesday
and Tuesday night...then energy in the southern stream will help to
support a storm system that should pass to our south on Wednesday.
Being on the northern fringe of this system...there will be the
potential for showers.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR flight conditions for areas south of Lake Ontario, with areas of
IFR/MVFR CIGS and lingering rain showers east of Lake Ontario this
evening. Gusty winds will continue to come down through the evening.

Increasing clouds and lowering CIGS tonight across all of western
and northcentral NY as low level moisture increases following the
passage of a cold front. No precipitation, but this will lower CIGS
to mainly MVFR with areas of IFR across higher terrain tonight.

Low clouds will gradually dissipate during Thursday, but mid and
high clouds will expand across the area from the south. Also a
chance of showers late in the day.

Outlook...

Thursday night and Friday...Mainly MVFR. Showers likely and MVFR
stratus.

Saturday through Monday...VFR/MVFR. A chance of showers.

&&

.MARINE...
Winds and wave action will continue to come down on Lake Erie where
Small Craft Advisories remain in effect into this evening.
Elsewhere, choppy...but sub-advisory conditions can be expected.

Winds will shift to the northeast and diminish tonight, with a
general northeast flow through Thursday night. This will result in
choppy conditions along the south shores of the Lakes, with
conditions approaching advisory criteria on Lake Erie.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LEZ020.
         Small Craft Advisory until 11 PM EDT this evening for
         LEZ040-041.

&&

$$

SYNOPSIS...Apffel/HSK/JM
NEAR TERM...Apffel/HSK/JM
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...Apffel/JM
MARINE...Apffel/JM