144
FXUS61 KBUF 181849
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
249 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 TUESDAY NIGHT/...
A mid and upper level ridge will become anchored over our region
this period, with mainly fair weather and building warmth.

A shortwave trough will ripple through this ridge over Canada Monday
night, possibly bringing a shower down into the Saint Lawrence
Valley. Otherwise moisture left behind this shortwave may aid in
development of a few spot showers or thunderstorms along a
strengthening lake breeze boundary Tuesday afternoon. Subsidence
with the ridge aloft should keep any activity isolated.

The southwesterly flow will steadily increase temperatures aloft at
850 hPa, such that at the surface most areas will see day to day
warming of a degree or two. By Tuesday, 850 hPa temperatures of +14
to +16 will yield widespread 80s, and perhaps a few 90 degree
readings in the Genesee Valley. The exception will be northeast of
Lakes Erie and Ontario where the southwest flow off the cool Lake
waters will hold back the heat for metro areas of Buffalo and
northern Watertown.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Low pressure tracking from Lake Superior to Hudson Bay will place
our region in the warm sector for much of the day Wednesday. With
SSW downslope flow will hedge on the warm side of guidance with
highs 85 to 90 across lower elevations, including Buffalo and
Rochester. 12Z model consensus brings a cold front through Thursday
evening, with a chance of showers and thunderstorms ahead of the
front Wednesday afternoon and showers and thunderstorms likely
Wednesday night with the frontal passage.

Possibly a lingering shower behind the front on Thursday with
afternoon temperatures still slightly above normal despite the cold
frontal passage. After this, weak high pressure will build across
the region resulting in mainly rain-free weather Thursday night
through Friday night. A secondary cold front will approach the
region Thursday night, and may pass through all or part of the area
Friday and into the weekend. Lower confidence in temperature
forecast for this time period, with forecast highs in the mid 60s to
mid 70s representing a consensus of model guidance. These could be 5
or more degrees warmer or cooler depending on the position of the
front. Chances of showers with the front will remain low, but a
stray shower can`t be ruled out on Saturday.

&&

.AVIATION /19Z 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 VFR. 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...Thomas
LONG TERM...Apffel
AVIATION...TMA
MARINE...TMA