193
FXUS61 KBUF 281539
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1139 AM EDT Sun Apr 28 2024

.SYNOPSIS...
A weak frontal boundary will sag southwards from Lake Ontario
tonight...and this could touch off a few showers...especially near
or east of the lake. The front will remain stalled over our area on
Monday with afternoon temperatures ranging from the lower 60s north
of the boundary to the lower 80s across the Southern Tier. While
there can be an afternoon shower or thunderstorm well south of
Buffalo and Rochester...most areas will be rain free. Temperatures
this week will average well above normal...especially Thursday and
Friday.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
An arm of loosely organized shortwaves extending to the east from
the Upper Great Lakes will lift northwards across our region this
afternoon. While this will certainly be enough to support scattered
to likely pops for showers and `garden variety` convection...the
vast majority of the afternoon will be rain free. As we press
through the mid and late afternoon...the activity over the Southern
Tier will peeter out with some clearing possible.

Otherwise...this afternoon will be somewhat humid with
temperatures that will be close to 70 with widespread mid and
even upper 70s across the Genesee valley and Finger Lakes region.

While the wave of shortwave energy will push north of our forecast
tonight...a weak cold front will sag south from Lake Ontario. This
boundary could touch off a few inconsequential showers...mainly near
and east of Lake Ontario...but more noticeably it will set the stage
for a duality in temperatures. The bisecting nature of the front
will lead to overnight lows that will range from the mid 40s across
the North country to between 55 and 60 across the Southern Tier.
Along with more shower activity to the north of the stalling
boundary...there will also likely be some fog.

On Monday...the aforementioned west to east oriented frontal
boundary will be stalled across our forecast area. Low level
convergence in the vcnty of the boundary that could result in some
afternoon showers and thunderstorms well south of Buffalo and
Rochester...otherwise impressive ridging aloft with relatively dry
air in the mid levels should prevent widespread pcpn from breaking
out. The bisecting frontal boundary will keep a large temperature
range over our region with max temps ranging from the lower 60s in
the Thousand Islands region to the lower 80s across the Southern
Tier.

Monday night...a negatively tilted mid level trough over the Upper
Great Lakes will shove its associated cold front across Lower
Michigan and southern Ontario. While this in turn will push our
stalled frontal boundary out of our region...we will have to turn
our attention to the showers and thunderstorms that will be
targeting our region from the northwest. Most of this activity
should hold off until after midnight. Unfortunately...this scenario
will most certainly set the stage for unsettled weather on Tuesday.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A surface cold front will slowly make its way east across New
York State on Tuesday...and in the process will generate fairly
widespread showers along with some scattered thunderstorms.
Given current timing projections for the frontal passage...the
best instability and therefore the best chance for any
thunderstorms will lie from interior sections of the Southern
Tier northeastward across the Finger Lakes and North Country.
While some shear will be in place...the currently expected
amount of cloud and shower coverage will likely help to keep
available instability across our region weak to modest...with
the better instability (and therefore the best chances for any
stronger storms) likely remaining confined to our south and
east. Meanwhile PWATs of 1.25-1.50" will probably support at
least some potential for some locally heavier downpours. As for
temps...highs will mostly range from the mid 60s to mid
70s...with the warmest readings across the upper Genesee Valley
and interior portions of the Finger Lakes.

By Tuesday evening...the increasingly wavy frontal boundary
will lie to the east of our region. A lingering potential for
some showers along our southeastern periphery of this slowly
departing system Tuesday evening will eventually give way to a
return to drier weather overnight and especially Wednesday as a
weak bubble of high pressure over the central Great Lakes builds
east across our region and gradually strengthens...with dry
weather then continuing through Wednesday night as the high
drifts across New England. Even with at least a somewhat cooler
airmass in place temps should still easily remain above average
for the last 36 hours of this period...with lows Tuesday and
Wednesday nights mostly in the upper 40s to lower 50s...and
highs on Wednesday generally running in the upper 60s to mid
70s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Moving into the long term portion of the forecast...the medium range
guidance packages are in good agreement on the axis of broad upper
level ridging sliding across our region on Thursday...with a nice
southerly low-level return flow in place in between high pressure
along the New England coastline and low pressure over the nation`s
midsection. This should result in a summerlike day with fairly
widespread highs in the 70s to lower 80s. Cannot completely rule out
a shower or two along our northwestern periphery later on in the day
as a warm front attendant to the Plains system snakes toward our
region...however at this point the day appears to be largely dry.

After that...our weather should remain rather warm but should also
begin to trend more unsettled through Friday as the aforementioned
storm system lifts across the Upper Great Lakes and swings its
trailing cold front toward our region. The most unsettled conditions
of this period then look to come Friday night/Saturday as the cold
front crosses our region and provides our next chance for showers
and a few thunderstorms...with the increased pcpn and introduction
of somewhat cooler air also allowing temps to pull back a bit for
Saturday (though these should still remain above normal).

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
A warm frontal segment will move ENE across the area this afternoon.
This will produce some showers with scattered thunderstorms. Fairly
widespread MVFR cigs are expected with this, with brief/localized
IFR vsby in downpours and thunderstorms possible. Coverage expected
to be very sparse and brief so did not include this in TAFs.

Frontal boundary will meander south tonight, resulting in lower
cigs and some fog tonight. IFR flight conditions are likely to
develop along this boundary, with areas of vsby 1SM or less in fog
at times. Fog and low cigs will mainly impact KBUF/KIAG/KROC/KART
with KJHW remaining south of the boundary.

Outlook...

Monday...VFR/MVFR with a chance of showers and thunderstorms.
Monday night and Tuesday...MVFR/VFR with showers becoming likely
along with a chance of thunderstorms.
Wednesday and Thursday...Mainly VFR.

&&

.MARINE...
A general weak southwesterly flow today. This will result in
conditions remaining below advisory criteria. This being said, a few
thunderstorms will become possible today with locally higher winds
and waves possible. Increasing northeast winds will result in choppy
conditions along the south shores of Lake Ontario late tonight into
Monday.

&&

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

&&

$$

SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...Apffel
MARINE...Apffel/Hitchcock