195
FXUS61 KBUF 012304
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
704 PM EDT Sat Jun 1 2024

.SYNOPSIS...
Dry weather will continue through tonight as high pressure across
the region drifts to the east coast. Weakening low pressure will
move into the Ohio Valley Sunday, bringing a chance of a showers and
a few thunderstorms, especially across Western NY from late morning
through the afternoon, and across the Finger Lakes during the
evening. Dry and warm weather will follow early next week.

&&

.NEAR TERM /THROUGH SUNDAY/...
Quiet weather will continue through tonight as a mid level ridge
across the region drifts to the east. High clouds will continue to
thicken and gradually lower overnight. The clouds and ongoing warm
advection will limit radiational cooling, with lows in the 55-60
degree range in most areas, with low 50s limited to the coolest
Southern Tier valleys and North Country.

A weakening mid level shortwave trough will cross the eastern Great
Lakes Sunday. An associated weak surface low over lower Michigan in
the morning will move into Western NY during the afternoon and wash
out as forcing continues to weaken. Weak large scale ascent in the
DPVA and height falls ahead of the trough will support a few showers
with uneven coverage Sunday. Expect rain chances to start increasing
in Western NY by late morning, then spread east across the Genesee
Valley and Finger Lakes during the afternoon and evening. Some
meager afternoon surface based instability develops, so an isolated
thunderstorm can not be completely ruled out.

Clouds will limit daytime warming some, with highs mainly in the
lower 70s across Western NY, and 75-80 along and east of the Genesee
Valley with a later arrival of thicker clouds and showers.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
Weakening mid level shortwave will exit east of the area Sunday
night, with any lingering scattered showers tapering off through the
first half of the night. Some patchy fog will be possible,
especially for areas that receive rainfall. Mild with lows mainly
mid to upper 50s.

Mid and upper level ridging will build over the region through the
first part of next week, while weak Canadian surface high pressure
ridges south over the area at the same time, with surface ridge axis
slowly shifting east across eastern NY and western New England by
Tuesday. As one would expect, this will provide mainly dry weather
across western and northcentral NY during this timeframe. Exception
will be along and inland of any lake breeze boundaries during the
afternoon/early evening hours as instability ramps up owed to strong
diurnal heating. This will be the case mainly across areas south of
Lake Ontario where a modest increase in low level moisture advection
will occur, bringing about the chance for a few isolated
showers/possible rumble of thunder across these aforementioned
areas. Otherwise, it will start to `feel` like summer again as both
temperatures and humidity see a day-to-day rise Monday into Tuesday.
Nothing oppressive as far as humidity levels go, although may start
to `feel` a touch on the muggy side by Tuesday as dew points start
to creep up into the low 60s. Temperatures on the other hand will be
above average and on the warm side. Highs Monday mid to upper 70s,
with some low 80s. By Tuesday, much of the area will climb into the
low to mid 80s, with upper 70s reserved for the higher terrain.
Monday night lows, mid 50s to low 60s.

Ridging surface and aloft will shift east across New England Tuesday
night, while a deepening upper level trough that will impact our
area later in the forecast period, starts to take shape across the
Canadian Prairies. More on that in the long term portion of the
discussion. In between these features, a weak mid level shortwave
will ride north over the central Great Lakes along the back side of
the mid level ridge. This will bring the chance for a few
showers/rumble of thunder to areas mainly south of Lake Ontario,
best chances across western NY closer to the shortwave. Humidity
levels will continue to increase with a muggy night on tap as lows
only fall back into the low to mid 60s for most of the area.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Broad mid and upper-level ridging extending from the southeastern
states to New England at the start of this period will gradually
give way to a negatively-tilted upper trough digging southeastward
across the Great Lakes Wednesday into Thursday...with this trough
then likely to cut off into a closed low that will take up residence
across our region Friday and Saturday. While the medium range
guidance packages unsurprisingly continue to struggle with the
details of this transition this far out...this will generally result
in our weather becoming much more unsettled as we push through the
middle and latter portions of the week...with initially above normal
temperatures also settling back to near to slightly below average by
Friday and Saturday.

Digging a little deeper into the forecast details...on Wednesday the
front flank of the approaching trough will start to approach far
western New York as we push through the course of the day. Combined
with daytime heating of our moderately humid airmass...this should
allow for the development of some scattered showers and thunder-
storms...with the greatest chances for these found from the Genesee
Valley westward. Further east pcpn chances should diminish with
increasing eastward extent... with it quite possible that the North
Country could remain mainly dry. Otherwise notably above normal
temperatures will continue for one more day...with highs ranging
from the mid-upper 70s across the higher terrain to the lower to mid
80s across the lower elevations.

Wednesday night and Thursday the elongating upper trough will
continue to expand its way southeastward across the Great Lakes...
with its attendant surface low over Northern Ontario likely pushing
a weakening warm frontal segment across our area Wednesday night...
followed by a prefrontal trough and trailing cold front between
Thursday and Thursday evening. Consequently...pcpn potential looks
to increase to the likely range (and likely the greatest levels of
the period) later Wednesday night and Thursday in concert with the
approach/passage of the above boundaries. Meanwhile a warm and humid
Wednesday night will be followed by high temps pulling back some to
the mid and upper 70s on Thursday due to the expected increase in
cloud and precipitation coverage.

Following the passage of this system`s cold front...notably cooler
and less humid air attendant to the upper low will then overspread
our region through the remainder of the week. This will result in
daytime highs pulling back into the mid 60s to lower 70s for both
Friday and Saturday...and nightly lows also settling back into the
lower to mid 50s. Meanwhile the presence of the upper level low/cool
pool aloft will support the potential for additional scattered
showers and storms Friday and Saturday...with chances for these
generally peaking each afternoon with daytime heating/increased
diurnally-driven instability.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
VFR will prevail through Sunday morning with mid/high clouds
thickening and lowering from west to east. A weakening mid level
trough and associated weak surface low will cross the eastern Great
Lakes Sunday. Ascent associated with this system will support a few
showers, starting late morning in Western NY then spreading east
across the Genesee Valley and Finger Lakes during the afternoon.
Expect spotty/uneven coverage of showers with isolated VSBY
restrictions in any moderate showers that develop. Meager
instability may support a few isolated weak thunderstorms in the
afternoon. CIGS will continue to lower, with MVFR developing across
Western NY during the afternoon as the low levels start to saturate.

Outlook...

Monday and Tuesday...VFR.
Wednesday...Mainly VFR with a chance for showers.
Thursday...Restrictions likely with showers and thunderstorms.

&&

.MARINE...
Quiet weather the rest of this weekend into early next week
with no marine headlines expected. A weak low moves northeast
from the Ohio Valley to just south of the lower Great Lakes late
tonight through Sunday with a chance of a few showers and
isolated thunderstorms. High pressure will then build into the
region Sunday night through Monday.

&&

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

&&

$$

SYNOPSIS...Apffel/Hitchcock/TMA
NEAR TERM...Hitchcock/TMA
SHORT TERM...JM
LONG TERM...JJR
AVIATION...Hitchcock
MARINE...Apffel/Hitchcock/TMA