304
FXUS61 KBUF 021513
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1113 AM EDT Thu May 2 2024

.SYNOPSIS...
High pressure across the western Great Lakes will ridge across the
region, resulting in mainly dry weather through Friday morning.
A series of fronts will then slide across the Great Lakes Friday
night through Sunday bringing the next round of rain showers and
possibly a few rumbles of thunder.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Ridging will build in across western and central NY through this
afternoon. Meanwhile, the weak shortwave that passed by to our north
during the early morning hours will dive southeast across far
northeastern NY and New England, but should remain just far enough
to our northeast to keep areas toward the North Country dry.
Somewhat cooler air will filter in behind the front which will knock
our temperatures down a bit from yesterday with highs mainly in the
mid to upper 60s south of Lake Ontario, with upper 50s to low 60s
east of Lake Ontario. Still a bit above average for early May.

Surface high pressure slides east of the area while upper level
ridge crests overhead Thursday night. These features will keep our
weather dry with overnight lows mainly ranging through the 40s, with
low 50s possible along the Lake Erie shore northwest of the
Chautauqua Ridge/Boston Hills owed to a weak southeasterly flow
developing on the back side of the high.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The axis of a mid level ridge will drift east across NY/PA on
Friday, with 850MB temps soaring to +14C by afternoon across Western
NY. This will bring summer-like temperatures to Western NY, with
highs in the upper 70s to lower 80s in most locations. The North
Country will be a little cooler, being farther removed from the
thermal axis over Western NY, with highs in the upper 60s to lower
70s. An ENE flow over Lake Ontario will also keep the south shore of
Lake Ontario much cooler, especially west of Rochester.

Most of Friday will be dry. The ridge axis will begin to drift east
by late afternoon, with height falls and DPVA reaching Western NY by
the end of the afternoon. This will support increasing clouds later
in the day, and a few spotty showers and thunderstorms may develop
by late afternoon across Western NY. This would be most probable
just east of Lake Erie in the typical lake breeze convergence zone
from northwest PA into southwest NY mainly south/southeast of
Buffalo.

Friday night through Saturday night unsettled weather will return to
the region. The mid level trough upstream will drift east into the
eastern Great Lakes and then stall as the downstream pattern
stagnates in response to a closed low over the North Atlantic to the
east of New England. A plume of deep moisture will become situated
across the eastern Great Lakes, with numerous convectively augmented
vorticity maxima drifting through the mean southwest flow across the
region.

The combination of moisture and forcing will bring occasional rounds
of showers Friday night across Western NY, and then the entire
region Saturday through Saturday night. The best chance of thunder
will be on the front side of the system late Friday afternoon and
Friday night when instability is greatest. Cooler temperatures will
then restrict the thunder potential Saturday through Saturday night,
although there may still be a slight chance of a few spotty
thunderstorms if there are enough breaks in the rain and overcast.
The clouds and showers will keep highs in the mid 60s for lower
elevations and around 60 for higher terrain Saturday.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Sunday, the mid level trough axis stalled over the eastern Great
Lakes since Friday night will start to make some eastward progress,
and also weaken with time. Lingering weak forcing and moisture will
still support a few rounds of showers, with the greatest coverage
likely to be east of the Genesee Valley.

Surface high pressure and a bubble of drier air will then build into
the Great Lakes Sunday night and Monday, with a return to mainly dry
weather. Model guidance begins to diverge with the timing of the
next system by Tuesday, with the GFS faster in the return of
moisture and forcing while the ECMWF/GEM are slower. Given the
slower trend of the ECMWF/GEM, kept POPs on the lower end of the
chance range.

Rain chances will increase Tuesday night through Wednesday as low
pressure moves into the upper Midwest, with a downstream warm front
moving northeast across the Great Lakes region. Enough instability
may return to support at least a slight chance of thunder by the
middle of next week.

Temperatures will continue to run above average through the period,
with highs in the 60s Sunday and Monday giving way to 70s by Tuesday
and Wednesday.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Mainly VFR conditions generally light breezes expected for the
remainder of the day as high pressure builds in across western and
central NY in the wake of the cold frontal passage. The exception
will be toward the North Country (KART) where the southwestern edge
of better low level moisture associated with shortwave diving
southeastward across New England will just graze this area. These
low level decks may produce a brief period of MVFR/low VFR CIGS late
this morning through mid afternoon before this feature moves further
southeastward away from our area. Any rain shower activity should
remain across far northeastern NY and New England.

High pressure in control tonight providing widespread VFR conditions
through the end of the TAF period.

Outlook...

Friday...Mainly VFR with a chance of afternoon showers and
thunderstorms across western NY.

Saturday...MVFR to VFR with showers likely and possible
thunderstorms.

Sunday...Morning showers, then a chance of afternoon showers,
otherwise mainly VFR.

Monday...VFR.

&&

.MARINE...
Mainly weak pressure gradients are expected through the end of the
work week into this weekend across the lower Great Lakes supporting
winds to generally remain below 15 knots. While the remainder of the
work week will remain quiet, a few showers and thunderstorms will be
possible Friday night through Sunday.

&&

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

&&

$$

SYNOPSIS...EAJ
NEAR TERM...JM
SHORT TERM...Hitchcock
LONG TERM...Hitchcock
AVIATION...JM
MARINE...EAJ/JM