-- Discussion containing changed information from previous version are highlighted. --
835
FXUS61 KBUF 250525
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
125 AM EDT Sat May 25 2024

.SYNOPSIS...
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While Saturday will not be a complete wash out...showers and gusty
thunderstorms will develop during the midday and afternoon in
response to a pair of fronts moving through the area. It will be
noticeably more humid as well. Weak high pressure will allow fair
weather to return later Saturday night with the finest weather of
the weekend slated for Sunday. A complex storm system over the Upper
Great Lakes will then support very unsettled weather for Memorial
Day...including the potential for drenching thunderstorms.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Fair weather will continue overnight as a mid level ridge axis
moves into the region and surface high pressure drifts to the
east coast. Mid and high clouds will start to increase from west
to east late tonight ahead of an approaching warm front.

Warm frontal segment drifts through the region Saturday placing
much of the area with the warm sector, ahead of an approaching
mid level shortwave trough and associated cold front. The risk
for showers and scattered thunderstorms will increase within the
warm sector, especially during the afternoon during peak
heating. Shear profiles not overly impressive, but SBCAPE values
expected to exceed 1000 J/kg could be supportive of some
stronger storms with the potential for strong winds and hail.
SPC has maintained a marginal severe risk for a good portion of
the area. Some risk for localized heavy rainfall with
precipitable water values near or exceeding 1.25". Mesoscale
guidance suggests the greatest risk for heavy rain and strong
thunderstorms is across the Western Southern Tier, however it
can`t completely be ruled out at any locations. Within the warm
sector, temperatures should reach the upper 70s to lower 80s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
The best lift and moisture will be across the eastern half of the
forecast area Saturday night. Showers and a few thunderstorms will
remain possible from the Finger Lakes region to the eastern Lake
Ontario region overnight. Showers will end from west to east across
western NY Saturday evening. Surface high pressure will build into
the region overnight. Patchy fog is possible for places that
decouple and clear out into Sunday morning. The greatest chance is
across the western Southern Tier and Niagara Frontier.

Ridging aloft and surface high pressure will be in place Sunday and
make for a pleasant, dry day across western and north central NY.
Fair weather won`t last long as a series of robust shortwave troughs
move across the Upper Great Lakes region and Ohio Valley Sunday
night into Monday. Initially, a warm front will move from southwest
to northeast across the forecast area. A 40kt low level jet combined
with a plume of moisture will lead to showers spreading across the
region overnight. Elevated instability and strong forcing at the
nose of the jet may result in a few thunderstorms. Surface
temperatures will fall Sunday evening before holding steady or
rising into Monday morning as southerly flow increases across the
region. The forecast area will be situated in a warm, moist airmass
Monday. Surface heating will increase surface based instability
especially across western NY Monday. Showers and thunderstorms will
increase in coverage as a cold front enters western NY Monday
afternoon. The combination of high PWATS, a strong low-level jet,
and a moderately-high freezing level will make for heavy rain in any
thunderstorms. Forecast soundings show drier air in the mid-levels
across western NY Monday afternoon which cuts down on the heavy rain
threat. On the contrary, saturated forecast soundings to 25k feet
are present east of Lake Ontario limiting surface-based instability
but increasing heavy rain potential. The cold front will gradually
move through the forecast area through Monday night and showers and
thunderstorms will diminish in coverage especially across western
NY. The heavy rain threat will last into Monday night east of Lake
Ontario.

Temperatures remain above normal Saturday night through Monday
night.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Broad mid-level trough will lie across the eastern Great Lakes and
Northeast throughout much of this next week and allow a few embedded
shortwave troughs to round its base. Overall this will support a few
rounds of rain showers. Due to the multiple shortwave passages,
timings of showers are difficult to pinpoint down this far out.

Also with the troughing overhead temperatures will be on the cooler
side with highs ranging in the 60s, and near 70s a few days. Lows
will dip down into the 40s each night.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
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Fair...VFR weather with light winds will persist through daybreak.

While VFR conditions can be expected for the vast majority of
Saturday...the passage of a pair of frontal boundaries will support
some gusty thunderstorms during the midday and afternoon. The
greatest risk for the convection over the western counties will come
between 15 and 21z...and for sites east of Lake Ontario between 18
and 00z.

Convection from the afternoon will move out of the area during the
evening hours. While this will leave primarily VFR conditions in
place through 06z...clearing skies will lead to some areas of fog
and stratus that will result in fairly widespread MVFR to IFR
weather through daybreak Sunday.

Outlook...

Sunday...Improving to VFR.
Monday...Restrictions likely with showers and thunderstorms.
Tuesday and Wednesday...Restrictions possible with showers.
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&&

.MARINE...
Winds will become south-southeasterly tonight on Lake Erie at 10
knots or less as a warm front lifts northward into the region.
Farther removed from the approaching warm front, winds turn
easterly on Lake Ontario and increase to 10 to 20 knots with
the stronger winds on the west end of the lake with possible
choppy conditions developing.

Winds on the lower Great Lakes will become more variable Saturday as
the warm front drifts through the region and the flow becomes light
enough for lake breeze circulations to develop. A few gusty
thunderstorms are possible during the afternoon ahead of an
approaching cold front with the potential for locally higher winds
and waves.

With the cold frontal passage winds turn east-northeasterly
generally under 10 knots Sunday, as high pressure briefly builds in
across the lower Great Lakes.

More notable winds will occur on Monday into Tuesday with increasing
southerly winds early Monday taking on a more west-southwesterly
component Monday afternoon into Tuesday. Winds could nudge into the
15 to 25 knots range with possible small craft headlines needed
during this time period. Scattered gusty thunderstorms will also be
possible Monday.

Boaters should continue to monitor the forecast, especially
given the holiday weekend which will likely increase boating
activity. This will especially be the case on Monday as
conditions on the lower Great Lakes will likely deteriorate.

&&

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

&&

$$

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