314
FXUS61 KBUF 291817
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
217 PM EDT Sat Jun 29 2024

.SYNOPSIS...
Showers and thunderstorm will possible through this evening which
could produce torrential downpours and gusty winds. A cold front
will cross the region tonight, with additional chances for showers
or a thunderstorms. The passage of the front will bring in less
humid conditions and drier weather. High pressure builds in on
Monday with dry weather through Tuesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
Beneficial rains so far...with many locales reporting over 1.25 to
1.5 inches of rainfall through 06Z. The overall lack of instability
has really kept the SVR potential at bay this afternoon. That
said...it wouldn`t take much for storms to fire up given ample shear
(0-6km 50 knts) across the region. So far the main concern has been
the heavy rain that has fallen in many spots. Given the above
mentioned rainfall totals....it wouldn`t take much for flash
flooding to occur if any additional thunderstorms fire up.

Otherwise...showers and thunderstorms will briefly dwindle in
coverage from west to east beginning this evening. After that...the
cold front will approach from the WNW late tonight and early Sunday
morning. There is some indications we might see a round of showers
with the front...but not all guidance is bullish on this idea. Right
now...the most widespread showers coverage appears to be east of
Lake Ontario.

With the passage of the initial cold front it will become quite
breezy Sunday, with increasingly more comfortable conditions due to
the tumbling Td`s. Interestingly enough...our high temperatures are
advertised to peak in the low to mid 70s by midday/early afternoon
then slowly falling thereafter. This is unusual for this time of
year... so this gives you a semblance of how strong the cold
advection will be in the wake of the first cold front. MaxTs Sunday
will generally be found in the 70s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
Sunday night the core of the upper level trough and secondary cold
front will slide south across our region. Coupled with upsloping and
lake influences (the latter owing to rather cool 850 mb temps
falling to around +5C to +6C)..the above should generate a fair
amount of cloud cover along with some scattered showers...with the
greatest pcpn potential lying east and southeast of Lake Ontario.
With this in mind have increased both PoPs and cloud cover notably
from blended guidance...which appears to be handling these rather
poorly. Otherwise it will be a much more comfortable night for
sleeping...with lows ranging from around 50 across the interior
Southern Tier and North Country to the mid 50s across the lake
plains.

Sprawling Canadian high pressure and plentiful dry air will then
slowly meander its way from the Upper Great Lakes to the mid-
Atlantic coastline Monday and Tuesday...while low-amplitude upper
level ridging builds across the region aloft. This will provide us
with fine weather to start off July...with highs in the upper 60s to
lower 70s Monday warming to the upper 70s and lower 80s on Tuesday
as a southerly return flow of warmer air develops around the
backside of the departing ridge. In between...ideal conditions for
radiational cooling will allow Monday night`s lows to range from the
mid-upper 40s across the interior of the Southern Tier/North Country
to the lower to mid 50s elsewhere. Humidity levels will also remain
comfortable throughout...with surface dewpoints only inching up into
the 55-60 range by later Tuesday.

Tuesday night the surface ridge will slip a little further
offshore...while the next mid/upper level trough and surface low
pivots across Manitoba and Ontario Provinces. With our region firmly
embedded within the deepening/strengthening southerly flow in
between these two systems...it will be a much warmer night than the
preceding two...with readings generally ranging through the 60s.
Meanwhile humidity levels will remain tolerable...as surface Td`s
will linger in the 55-60 range.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Wednesday and Thursday the aforementioned trough and surface low
will continue to make its way eastward to Labrador...and in the
process will ease a weak trailing cool front across our area
Wednesday night and early Thursday.

Out ahead of this boundary heat will build on Wednesday...with 850
mb temps surging into the upper teens...thereby supporting highs
climbing back to the mid 80s to lower 90s in most areas. Humidity
levels will also be on the increase...with surface dewpoints
climbing into the mid-upper 60s and lending a decidedly muggy feel
to the afternoon. As the cool front impinges upon this sultry
airmass later Wednesday afternoon and especially Wednesday
evening...it should help to set off at least some scattered
convection...which could prove problematic for any holiday fireworks
displays scheduled for Wednesday evening.

Convection should then tend to diminish in coverage from northwest
to southeast later Wednesday night and Thursday as the passing cool
front slips off to our south and ushers in a slightly cooler and
less humid airmass...though cannot rule out some spottier showers
and storms lingering into Thursday afternoon near the NY/PA border.
Otherwise slightly cooler highs in the lower to mid 80s are expected
for Independence Day...though humidity levels will likely remain
elevated.

The weak cool front then looks to stall out not far to our south
Thursday night and Friday...as a weak wave of low pressure develops
and ripples eastward along the boundary. While the medium range
guidance packages unsurprisingly exhibit differences on the timing
and strength of this wave...a rough consensus would currently
suggest a largely dry evening on July 4th...followed by a renewed
potential for scattered showers and storms later Thursday night into
Friday...with the latter greatest near the Pennsylvania border. This
being said it`s pretty early...with changes to this overall scenario
certainly possible over the coming days. Otherwise...it will likely
remain warm and on the humid side through the end of the week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A cold front nearing the region will bring showers and thunderstorms
this afternoon and evening which will likely produce periods of MVFR
to IFR conditions.

The showers and thunderstorms will taper off from west to east by
late this evening and tonight...MVFR to IFR cigs will likely remain
across area terminals.

Outlook...

Sunday...VFR/MVFR with scattered showers.
Monday and Tuesday...VFR.
Wednesday...VFR/MVFR with showers and thunderstorms likely.
Thursday...Mainly VFR with a chance of a shower or thunderstorm
across the S. Tier.

&&

.MARINE...
It will be quite unsettled today...as a broad storm system centered
north of the SOO will push several frontal boundaries across the Lower
Great Lakes. This will result in widespread showers and possibly some
gusty thunderstorms. Meanwhile...moderate to fresh southerlies will
direct the greatest wave action into Canadian waters. The exception
will be the far east end of Lake Ontario where waves will be
significant enough to warrant a small craft advisory for sites north of
Mexico Bay. Otherwise...expect fairly choppy conditions...especially
well offshore.

Winds will weaken somewhat tonight while veering to the southwest. This
should allow the headline for eastern Lake Ontario to expire.

Fresh to strong westerlies can then be expected in the wake of a cold
front on Sunday. This will likely lead to a fresh round of headlines
for at least the eastern half of Lake Ontario...while choppy conditions
will be found elsewhere.

Looking further ahead...high pressure drifting across the region Monday
and Tuesday will offer fine conditions for recreational boating with
generally light winds and negligible waves.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for LOZ045.

&&

$$

SYNOPSIS...AR/RSH
NEAR TERM...AR/RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...AR/RSH
MARINE...AR/RSH