653
FXUS61 KBUF 181813
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
213 PM EDT Sat May 18 2024

.SYNOPSIS...
A few showers or an isolated thunderstorm will be possible this
afternoon inland from the lakes. Dry weather returns areawide
tonight which lasts through Tuesday. It will also become
unseasonably warm with temperatures climbing well above normal.
Unsettled weather returns by mid-week and turning progressively
cooler.

&&

.NEAR TERM /THROUGH SUNDAY/...
Breaks developing in cloud cover the afternoon across western New
York. Instability will continue to build inland from the lakes with
scattered coverage of showers and isolated thunder. The best chance
for convection will be from the interior Southern Tier through the
Finger Lakes. Overall cell motion will be slow within a weak flow so
heavy downpours are certainly possible.

Any lingering convection will quickly diminish with the loss of
daytime heating early this evening. After that, quiet and dry
weather will take hold. Lingering low-level moisture due to the will
allow for some fog formation overnight, especially across western
New York. Expect overnight lows in the 50s.

After some early morning fog and stratus, mainly dry weather is
expected Sunday as a mid and upper level ridge starts to build
overhead. There will be an outside chance for some diurnally
driven scattered showers across the Genesee Valley/Finger Lakes
with a weak lingering surface convergent boundary in place. High
temperatures should peak in the mid to upper 70s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Mainly dry weather expected this period as mid and upper level ridge
builds overhead, while elongated surface ridge remains anchored in
place, stretching from the Mid Atlantic coast to the New England
coast. With very weak synoptic flow in place, expect developing
onshore flow with lake breezes pushing inland both days that will
keep areas along and near the lakeshores a bit cooler than inland
areas.

The only small chances for any precip will be: Sunday during peak
heating with a weak lingering surface convergent boundary lying
across the Genesee Valley/Finger Lakes region where a few scattered
diurnally driven showers may bubble up. On Monday, humidity levels
start to rise a bit more with a deeper southwesterly flow becoming
established as mid and upper level ridge axis shifts just to our
east. Strong diurnal heating combined with the increased moisture
may be enough to spark a few showers along any aforementioned lake
breeze boundaries. Confidence is low at this point of this
occurring, so capped PoPs below SChc for now. Otherwise, most areas
remain dry through the period.

The main story will be the warmth. Rising heights aloft associated
with mid and upper level ridge building overhead, a continued
south/southwest low level flow, and a good deal of sunshine will
help boost temperatures to well above average levels by the start of
the new work week. Expect highs Sunday mainly in the mid to upper
70s, with upper 70s to mid 80s on Monday.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Unfortunately, the strong mid and upper level ridge will start to
weaken by Tuesday as successive shortwaves traversing the northern
periphery of the ridge start to knock it down. That said, outside of
any diurnally driven activity (mainly along and inland of any lake
breeze boundaries), which at this time looks to be minimal, better
chances for showers and storms will remain north of the Canadian
border where the better forcing will stay for time being. It will be
even warmer on Tuesday with increasing southwesterly flow promoting
better diurnal mixing, which will help boost afternoon highs into
the low to mid 80s across the bulk of western and northcentral NY,
with a few upper 80s not out of the question for the traditionally
warmer spots across the Genesee Valley and lake plains. It will be a
bit cooler along the lakeshores.

As is typical this far out in time, model guidance differs some on
the timing of the strong cold front that has been advertised to
impact the area in the mid to late week timeframe. At this point,
front looks to cross the area sometime Wednesday night or Thursday.
This will yield another very warm summer-like day on Wednesday, as
highs will once again soar into the 80s for much of the area. That
said, precipitation chances will increase Wednesday afternoon as a
lead shortwave and associated prefrontal trough approach the area
ahead of the actual cold front, with the best chances for showers
and storms across western NY during the second half of the day.

Unsettled weather can then be expected as waves of low pressure
moving northward along the slowly eastward progressing cold front
bring periods of showers and storms to our region for Wednesday
night and Thursday, before high pressure builds back in providing a
dry finish to the work week. As noted in the previous discussion, a
cooler airmass is expected to filter in across the northeastern U.S.
in the wake of the cold fropa, however there is still model
discrepancy in just how cool that airmass will be, as well as the
exact timing of its arrival. All this said, just using pattern
recognition alone lends to fairly high confidence that cooler
weather is on the way for the latter half of the work week and
potentially into the upcoming holiday weekend. Stay tuned.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A few showers or even an isolated thunderstorm will develop this
afternoon across Western NY. The convection will be mainly focused
across the Southern Tier into the Finger Lakes, with low confidence
in any storm impacting any TAF site.

Any lingering convection will diminish with the loss of daytime
heating early this evening. There will be some fog possible
overnight which may bring some impacts with LIFR-IFR conditions.

Outlook...

Sunday through Tuesday...mainly VFR.

Wednesday...VFR-MVFR. Showers and thunderstorms likely.

Thursday...Mainly VFRR. A chance of showers and thunderstorms.

&&

.MARINE...
A highly saturated air mass will continue over the lower Great Lakes
tonight allowing for fog and stratus to develop over the lakes. Poor
visibility conditions may redevelop and become widespread tonight
into Sunday morning on Lake Erie and the western end of Lake Ontario
with light flow.

Otherwise, light winds with minimal wave action expected on the
lakes through Monday.

South winds develop and begin to pick up by Tuesday as a cold front
near the eastern Great Lakes but conditions will likely remain below
small craft levels. The next chance at small craft conditions may
materialize by midweek as low pressure sends a cold front through
the lakes.

&&

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

&&

$$

SYNOPSIS...AR/TMA
NEAR TERM...TMA
SHORT TERM...JM
LONG TERM...JM
AVIATION...TMA
MARINE...TMA