578
FXUS61 KBUF 181610
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1210 PM EDT Sat May 18 2024

.SYNOPSIS...
A few showers or an isolated thunderstorm will continue to be
possible today. Dry weather returns areawide tonight which lasts
through Tuesday. It will also become unseasonably warm with
temperatures climbing well above normal. Unsettle weather returns by
mid-week and turning progressively cooler.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Low clouds and some lingering pockets of fog (mainly along the Lake
Erie shoreline and out into the lake) will gradually improve
through this afternoon. This will allow for limited instability
to build with advertised 300-700 J/kg. With lingering moisture
and effects from a trough we could see a few showers or even a
thunderstorm develop this afternoon. The best chance to see a
shower or storm will be found across Western NY (Southern Tier)
into the Finger Lakes, and along any subtle boundary. Highs this
afternoon will be found in the 70s for most locales.

Tonight...any lingering showers will quickly diminish with the loss
of daytime heating. After that...generally quite and dry weather
will take hold. That said...with lingering low-level moisture due to
the recent rains some fog formation will be possible overnight.

Otherwise...a pleasant night is expected with lows found in the 50s.

&&

.SHORT TERM /6 AM SUNDAY MORNING 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 /16Z SATURDAY THROUGH WEDNESDAY/...
Pockets of 1-2K foot stratus will slowly lift the rest of the
morning. More breaks will develop this afternoon with most areas
going VFR by 18z. A few showers or even an isolated thunderstorm
possible this afternoon across Western NY. Mainly focused across the
Southern Tier, and along any subtle boundary with low confidence
in any storm impacting TAF sites.

Tonight...any lingering showers will diminish with the loss of
daytime heating. 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. A chance of showers and thunderstorms.

&&

.MARINE...
The only thing to contend will this afternoon will be some
patchy dense fog on Lake Erie this afternoon (mainly west of
Silver Creek).

A highly saturated air mass will continue over the lower Great
Lakes tonight allowing for additional for fog and low 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...AR/TMA
SHORT TERM...JM
LONG TERM...JM
AVIATION...AR/TMA
MARINE...AR/TMA