061
FXUS61 KBUF 120255
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1055 PM EDT Sat May 11 2024

.SYNOPSIS...
A weakening area of low pressure will slowly cross our region
overnight, resulting in areas of showers. The precipitation will
gradually taper off during the day Sunday as weak high pressure
noses into the area. While noticeably warmer weather will move in
for Monday, it will also once again become unsettled with
increasingly widespread showers and thunderstorms that will persist
into Tuesday.

&&

.NEAR TERM /UNTIL 6 PM SUNDAY EVENING/...
A mid level shortwave and attendant weak surface low will slowly
cross the region overnight. A swath of deep moisture ahead of this
system that produced widespread showers across western NY, is now
slowly pushing northeast into central NY and the eastern Lake
Ontario region.

The aforementioned area of weakening low pressure will then slowly
push across the forecast area overnight. While the bulk of the
associated showers will be found along and immediately ahead of an
attendant occlusion in the area of strongest low level convergence,
the precipitation will tend to broaden out during the course of the
overnight. Working into the second half of the night, the showers
will tend to give way to areas of light rain showers with some
patchy fog, mainly under the stacked low itself. Rainfall amounts
will generally range from a tenth to a quarter inch. Lows tonight
will range from the low 40s across the higher terrain to the mid and
upper 40s elsewhere.

The stacked low will further weaken on Sunday with its mid level
support briefly `opening up` enough to allow the mid level system to
exit across New England. Unfortunately, it appears even though the
surface low completely falls apart over our area, a weak surface
convergence boundary will linger, and looks to set up in the
vicinity of the Genesee Valley/Finger Lakes region. This will mean
as most areas dry out Sunday afternoon, some showers will continue
across this aforementioned area into the afternoon, finally tapering
by off late in the day. Otherwise, for the remainder of western and
north-central NY, a low amplitude shortwave ridge will build across
Lower Michigan to southern Ontario in its wake. Drying in the mid
levels will accompany the associated subsidence so that the
precipitation will completely end from west to east with enough
clearing to allow for some afternoon sunshine and a decent ending to
the weekend. Daytime highs will range from the mid 50s to low 60s.

A warm front will work its way northeastward across our forecast
area Sunday night. While this should only result in an increase in
cloud cover, there will be the chance for some showers over the
Niagara Frontier and possibly the Thousand Islands region by
daybreak. Lows will again range from the low 40s across the higher
terrain to the mid and upper 40s elsewhere.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Very active weather during this time frame with periods of showers
and also chances of thunderstorms.

The mid-level low spinning near James Bay will direct a cold front
towards the eastern Great Lakes Monday morning with increasing
chances for showers. There will also be some thunderstorms with this
boundary, especially as diurnal instability increases in the
afternoon. That said...another mid-level low over eastern Kansas
will begin to advance east towards the Mississippi river valley
by late Monday afternoon. As it does so...it is advertised to
interact with the front over our region. There is some indication
that it will nudge the front back north as a warm front. This would
place us again back in the warm sector with a brief period of
decreasing showers and storms by Monday night. However...it does not
appear to last very long as the eastward advancing low draws the
front back south by Tuesday with accompanying deeper moisture. We
should see our fair share of showers Tuesday but there is some level
of uncertainty as the southern stream low begins to tracks into the
mid-Atlantic region.

Tuesday night...the speed and track of the low will determine
weather we continue to see wet weather areawide or a slow but
gradual drying trend.

Overall...near to a tad bit above normal max temps with highs in the
upper 60s to low 70s. Lows will generally be found in the 50s.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
A weakening mid-level low centered over the northern Quebec
Wednesday morning will continue to pull northeast into the Canadian
Maritimes by Thursday morning. Meanwhile, ridging to the west across
the Upper Midwest and western Great Lakes Wednesday will build
across the remainder of the Great Lakes into Thursday night before
the next trough dives southeast across the Central Plains Thursday
night into the start of the weekend.

With weakened low and associated mid-level trough overhead overhead
of the area Wednesday, rain showers associated with the cold front
the crossed the area Tuesday, will gradually end from northwest to
southeast Wednesday.

As the aforementioned mid-level ridging pushes east across the Great
Lakes, associated surface high pressure will also move into the
eastern Great Lakes. This will result in a period of dry weather
Wednesday night thorugh much of Thursday.

The next chance for showers will return Friday and last into the
start of the weekend as warm front pushes across the area. Model
guidance this far out remains differed with the placement and track
of the upper level features and low level features. Therefore, kept
rain shower chances on the lower end due to the lack in confidence.

Expect a gradual warming trend throughout much of next week, with
subtle warming each day. By the end of the week the temperatures
will have rebounded to slightly above normal.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A stacked area of weakening low pressure will approach from
southwestern Ontario Province late this evening before moving across
the area overnight. This will continue the slow degradation of
flight conditions from west to east through this evening. Most low
decks are currently SCT/BKN in the low VFR range (3-5kft). Exception
is across the western Southern Tier (KJHW) where MVFR CIGS continue
to be observed.

A swath of showers ahead of this system will continue to work across
the eastern half of our area through the overnight hours. The
precipitation will be accompanied by CIGS that will lower to MVFR
levels across the remainder of the area, mainly from late this
evening into the overnight when IFR CIGS will become common for most
areas south of KBUF and KROC. A period of IFR CIGS will also become
possible across far western NY (KBUF/KIAG) later tonight into the
first part of Sunday morning. Expect at least scattered showers with
some patchy fog across the region in the wake of the steadier
precipitation as the mid level low moves across the area overnight.

IFR/MVFR CIGS over the region Sunday morning will then gradually
improve to VFR levels from west to east through the afternoon hours
as drier air associated with weak high pressure moves in across the
area. Lingering light showers will continue through midday or so.

Outlook...

Monday and Tuesday...VFR/MVFR with the likelihood for showers and
thunderstorms.
Wednesday...Improving conditions with precipitation exiting.
Thursday...VFR weather.

&&

.MARINE...
Mainly light, variable winds (less than 10 knots) will be the rule
through Sunday night, although southwest winds becoming northwest
later tonight may approach 15 knots between Dunkirk and Ripley
producing some moderate chop in this area. A more pronounced
southwesterly flow (10-15 knots) will develop on eastern Lake Erie
Sunday afternoon ahead of a warm front approaching from the west
that will bring some light to moderate chop, but waves should mainly
be less than two feet.

Southwesterly winds on Lake Erie/western Lake Ontario and southerly
winds across eastern Lake Ontario will freshen on Monday with near
Small Craft Advisory conditions possible across these aforementioned
areas. Otherwise, winds and waves are expected to remain well below
Small Craft conditions with just some light chop at times through at
least Tuesday.

&&

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

&&

$$

SYNOPSIS...JM/RSH
NEAR TERM...JM/RSH
SHORT TERM...AR
LONG TERM...EAJ
AVIATION...JM
MARINE...JM