047
FXUS61 KBUF 271816
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
216 PM EDT Mon May 27 2024

.SYNOPSIS...
Low pressure will send a cold front east with chances for showers
and thunderstorms this afternoon into this evening. Some of the
storms may have the potential to generate strong gusty
winds...mainly across the Finger Lakes and Eastern Lake Ontario
regions. Unsettled weather will persist on Tuesday then a drying
trend and cooler conditions will take hold for the rest of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
Svr Wx wise its been quiet so far with just a few embedded
stronger cells (low top convection) within the shower activity.
The main batch of shower is moving east across the Finger Lakes
and eastern Lake Ontario region. However...there is more cells
firing in its wake this afternoon and will continue to monitor
the situation.

Svr Wx details can be found below...

A Svr thunderstorm watch has been issued for Wayne, N. Cayuga,
Oswego, Jefferson, and Lewis County until 9PM.

A potent shortwave will send a cold front east with additional
chances for showers and possibly some strong to severe storms this
afternoon into early this evening. The greatest threat for severe
storms will `likely` be from the Finger Lakes ENE into eastern Lake
Ontario region. That said...the `limiting` factor for SVR storms
will be the amount of available CAPE. HRRR and various other hi-res
guidance only show values around 1100 j/kg this afternoon. Even
so...there will be plenty of shear (40 knots 0-6km) to support
organized storms. SPC has placed the above mentioned areas in a
slight risk for SVR storms. The other thing that needs to be watch
is the potential for flash flooding. With a moisture rich
environment in place...PW values in the 1.7" to 1.9 range...any of
the stronger cells will produce localized torrential downpours.
Given this threat...a marginal risk for excessive rainfall blankets
our entire CWA.

Otherwise...one additional thing to mention outside of the storms
today is the gusty winds northeast of the lakes. We will `likely`
see breezy conditions with gusts up to 40 mph. Highs will peak in
the 70s for most locales.

Surface low pressure lifts off into western Quebec by this evening
with its trailing cold front entering and crossing the region. We
should see a notable down tick in showers activity and storms with
its passage for a chunk of the night. This will be courtesy of the
mid-level dry slot swinging into the region. However...this dry
period doesn`t last very long as a potent mid-level shortwave drops
towards the eastern Great Lakes overnight. All indications are that
we will once again see increasing chances for showers as we head
into Tuesday.

Tuesday...A robust shortwave with the cyclonic flow will rotate
across the region. This will be accompanied by the next surge of
deeper moisture. Again showers and some thunderstorms will be
possible...especially during the midday and afternoon hours. Highs
on Tuesday will `likely` peak in the 60s to near 70F. It will also
be quiet breezy with westerly winds gusting up to 35 mph at
times.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A potent trough and then a cold front will track across the area
Tuesday night into early Wednesday morning. As the trough tracks
across the area, showers will continue through the first half of the
night, before becoming less organized. Forcing from the trough will
provide the main focus for showers during the evening and early
overnight, while the cold front will move through and continue the
potential for showers. Have included sChc of thunder this update as
there could be just enough lingering instability early in the night
to support a few isolated thunderstorms, though this threat should
quickly wane through the night with the absence of diurnal heating.
Overall synoptic moisture ahead of the trough will be generally low
with PWATs of around an inch, and lowering some to around three
quarters of an inch after it crosses the area. With these lower
moisture values and weaker forcing from the cold front, showers that
do linger into the morning on Wednesday will be less organized. Most
areas can expect less than a tenth of an inch of rainfall, with the
greatest amounts east of Lake Ontario where forcing and moisture
will be slightly better. Temperatures on the night will be in the
upper 40s for the higher terrain to the low 50s for the lower
elevations.

Wednesday, showers will linger across the area, with the best chance
for showers southeast of Lake Ontario toward the NY/PA border.
Showers will taper off and track out of the area from northwest to
southeast. By the afternoon, showers should be limited to a general
area from the NY/PA border, to the Finger Lakes & to the western
ADKs. Northwest flow over the region will help keep temperatures
below normal, with highs in the mid 50s to upper 60s from the higher
terrain to lower elevations respectively.

Wednesday night, earlier showers should be out of the area, minus a
few sprinkles for the Southern Tier and for areas well southeast of
Lake Ontario. Clearing skies from northwest to southeast, along with
a mostly northerly flow will bring one of the cooler nights the area
has seen in a while with overnight lows dropping to the low to upper
40s.

The region will remain situated under broad, positively tilted upper
level troughing centered over the Canadian Maritimes Thursday. To
the west, a strong, progressive ridge of high pressure will be
building eastward over the Great Lakes region. The surface high from
this feature will "undercut" the initial upper level troughing to a
degree, so while it should be another day of cooler than normal
weather, it will be drier across the region compared to Wednesday.
There remains a very low chance (15-20%) chance of showers across
portions of the North Country Thursday afternoon, which will be
further removed from the stabilizing effects of the high to the west.

Cool, dry and tranquil weather then expected Thursday night as the
upper level trough axis quickly pivots away from the eastern Great
Lakes and into New England. Temps will again fall back into the 40s
overnight.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A large area of high pressure and stout ridge will build east into
the region during the long term period. The surface high and large
ridge will be centered over the region from Friday afternoon through
Saturday evening, ensuring fair dry weather.

There are some timing issues with the next incoming trough and how
quickly the large ridge weakens and/or moves east. Due to this, some
guidance is bringing in the potential for showers starting on Sunday
morning, but with the lack of certainty, left at most sChc POPs.
Rain chances increase some on Monday as another weak shortwave moves
across the Great Lakes region on the lee side of the building ridge.

Temperatures for the period will start out near normal values in the
upper 60s and low 70s Friday, though warm to around 5-10 degrees
above normal by Sunday and Monday.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
An area of moderate to heavy showers with embedded thunderstorms
will bring MVFR to IFR Cigs and lower Vsbys at KART and KGTB at
time this afternoon.

Elsewhere...expect VFR to MVFR Cigs with chances for showers and
thunderstorms at times.

The showers and residual thunderstorms this evening will taper off
from west to east...as a cold front will press through the region.

Tonight...a cold front will cross the region with showers and
thunderstorm diminishing in coverage. However...MVFR to IFR
CIGS will develop especially east of the lakes overnight.

Outlook...

Tuesday...Showers and thunderstorms possible with restrictions.
Wednesday...VFR to MVFR cigs with a chance of showers.
Thursday through Saturday...VFR.


&&

.MARINE...
Southerly winds have strengthen sufficiently enough to issue
small craft advisories for all area lakes.

There will be thunderstorms throughout the region...some of
which could become strong gusty winds. The highest risk for
significant convection will be over the eastern half of Lake
Ontario this afternoon and evening. Mariners should be extra
vigilant to any statements or warnings regarding this activity.

Moderate southwest winds will continue into tonight and become
westerly with small crafts in place on the lakes through
Tuesday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ020.
         Small Craft Advisory until 8 PM EDT Tuesday for LEZ040-041.

&&

$$

SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...PP/SW
LONG TERM...PP/SW
AVIATION...AR
MARINE...AR