065
FXUS61 KBUF 171822
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
222 PM EDT Tue Jun 17 2025

.SYNOPSIS...
Showers and thunderstorms continue throughout the Western New York
region today before receding overnight, with showers and
thunderstorms forming slightly further East on Wednesday as well. A
cold front will move through on Wednesday night into Thursday,
bringing the potential for severe weather Thursday. Building high
pressure across the Great Lakes late this weekend will bring
unseasonably warm temperatures and increased humidity through the
start of the week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
Partly cloudy skies blanket western and north central New York early
this afternoon. Additionally, a few scattered showers are starting
to pop up southwest of the New York State line in Pennsylvania due
to a warm front lifting northeast across the lower Great Lakes today
and a passing convective shortwave trough. This being said, with the
passage of the convective shortwave trough during peak heating this
afternoon, showers and thunderstorms will continue to blossom. With
the lack of wind shear, thunderstorms will not build to great height
and therefore be just garden variety storms. However, as the better
lift from the passing shortwave intersects the axis of better
moisture across the Southern Tier, a few heavier downpours will be
possible.

The loss of daytime heating and therefore corresponding instability
and weakening lake breeze circulations will support convection to
taper down through the evening. However, incoming frontal boundary
and ample low level moisture will support a few spotty showers
throughout the overnight period, especially from the Southern Tier
northeastward across the Finger Lakes and eastern Lake Ontario
region. Additionally with the lingering moisture and cooling
temperatures toward the dewpoint tonight, patches of fog are likely
to form across the terrain of the Southern Tier.

A mid-level trough will then push east into the Great Lakes
Wednesday as a cold front crosses the central Great Lakes towards
the lower Great Lakes, placing the forecast area beneath the warm
sector ahead of the front. Increasing warmth and humidity along with
diurnal instability will support the chances for showers and
thunderstorms again Wednesday afternoon and evening, mainly inland
from the lakes. Similar to today, thunderstorms should be of the
garden variety as shear values are unfavorable however, heavy
downpours will be possible due to ample moisture.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A prefrontal trough and cold front push through the area Wednesday
night into Thursday morning, with an additional round of showers and
thunderstorms. Unfavorable timing should limit severe threat, but
precipitable water value over 1.5" suggests the potential for
locally heavy rainfall. Some guidance tracks a weak secondary sfc
low along the front, increasing the potential for heavier showers.
There may be enough instability for the eastern half of the forecast
for some strong to severe thunderstorms. The greatest potential for
severe thunderstorms is for far eastern Lewis County, where SPC has
a `Slight Risk` for severe thunderstorms. There is also a `Marginal
Risk` for excessive rainfall from WPC for the entire forecast area
on Thursday as well, with the heaviest rainfall expected along and
ahead of the front. Convection will gradually diminish late Thursday
as the cold front exits. Some guidance continues a few showers
through the night on Thursday with the trough axis of the larger
scale trough over the region.

Friday, some showers will be possible with the remnants of upstream
convection and a shortwave trough within a northwest flow. Guidance
is starting to back off some on the potential for showers/storms, but
this will be closely monitored.

Temperatures will reach the mid 70s to near 80 across much of the
area for the period. With the passing front on Thursday,
temperatures will be coolest to warmest from west to east. On
Friday, as temperatures start to warm some, the coolest areas will
be across the North Country, where cooler air will be slowest to
warm.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The next stout upper level ridge will slide across the Gulf States
Saturday before amplifying northeastward Sunday and into the start
of next week. This upper level feature will bring steady increasing
heat and humidity into the region for the weekend and into the start
of the new work week. However, an ill-timed shortwave ridge-runner
will support the possibility for a few rounds of showers and
thunderstorms Saturday through Sunday before surface high pressure
then dominates overhead for the start of the week. As alluded to
previously, the combination of 500 mb heights building to near 600dm
over the Ohio Valley and lower Great Lakes would support very hot
and humid conditions with heat index values climbing well into the
90s starting Sunday, and continuing through the rest of the forecast
period.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
A mix of VFR to MVFR ceilings are spread across the forecast area
from a blanket of clouds associated with a northeastward lifting
warm front. As this front approaches this afternoon and evening,
chances for showers and a few thunderstorms will increase as a
convective shortwave trough passes across the region. The best
chances for thunderstorms will occur across the Southern Tier and
Upper Genesee Valley.


Ceiling heights will settle back to lower terrain MVFR and higher
terrain IFR tonight. Additionally, some patches of fog are likely to
form tonight, especially in areas that received a shower
today due to increased surface moisture.

Outlook...

Wednesday and Thursday...VFR/MVFR with showers and thunderstorms
likely.

Friday...Mainly VFR. A chance of showers and thunderstorms,
mainly east of KROC.

Saturday...Mainly VFR. Increasing chances for showers and
thunderstorms.

Sunday...Mainly VFR.

&&

.MARINE...
Light southeast to southerly flow this afternoon due to a stable
regime of cool lakes and warm inland temperatures. This flow will
become slightly stronger and more defined tonight as the airmass
cools and lake breeze circulations weaken. The wind flow will become
more southwesterly tomorrow, but wind speeds will likely remain
below small craft advisory criteria.

By Thursday, a cold front will be drawing upon our region and a
tightening pressure gradient ahead of the front will allow for
southwest winds to increase to possible SCA criteria on both lakes.
This flow will also increase the waves on the lakes especially the
eastern half of Lake Ontario by Thursday evening where waves may
breach the 4-foot mark.

&&

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

&&

$$

SYNOPSIS...ACI/EAJ
NEAR TERM...EAJ
SHORT TERM...SW/TMA
LONG TERM...EAJ
AVIATION...EAJ
MARINE...EAJ/Thomas