366
FXUS61 KBUF 281905
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
305 PM 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 THURSDAY/...
An upper level ridge across the Northeast region early Tuesday will
move off the east coast through the afternoon. A cold front will
extend from Georgian Bay to central Lake Erie and into central Ohio
Tuesday morning. Most of the forecast area will be in the warm
sector in the morning, with the exception of the North Country/Saint
Lawrence Valley where they remain on the cool side of a warm front.
The combination of deep moisture and an approaching cold front
increases confidence that showers will be entering far western NY
around daybreak Tuesday. The risk for lightning is low, however not
non-zero. There is good agreement that the cold front will move
across the forecast area Tuesday, however confidence is medium that
showers will stay intact and move across the entire forecast area
through Tuesday afternoon. The best chance for showers and
thunderstorms will be across interior portions of the forecast area
where daytime heating will increase the probability of showers and a
few thunderstorms. Locations across the Niagara Frontier may only
see showers Tuesday morning and they stay dry the rest of the day.
The risk for strong to severe storms is low due to the timing of the
front Tuesday. Most of the forecast area will be behind the front by
Tuesday afternoon and result in instability further east. Any
thunderstorms will be capable of heavy rainfall due to anomalously
high PWATS for late April. High temperatures will range from the
upper 60s to low 70s across western portions of the forecast area to
the mid to upper 70s across the Finger Lakes region.

The front will move east of the forecast area Tuesday night. Showers
will diminish across north central NY Tuesday evening. Mostly dry
weather expected across western NY overnight. Lows will fall into
the upper 40s to low 50s.

Surface high pressure will move into the region Wednesday through
Thursday and dry weather is expected. Temperatures will remain above
normal with highs in the 70s both days, cooler conditions expected
near the lakeshores.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Largely dry weather Thursday night will encompass much of the
forecast area overnight. However....we will need too keep an eye on
a warm frontal boundary extending east from a low pressure system
tracking across the Midwest into the Great Lakes region. This would
mainly be for the North Country where we have kept low end PoPs (20%
or less) for a shower or stray thunderstorm. After that...increasing
moisture will be drawn up ahead of an approaching cold front. This
will once again bring increasing chances for showers by Friday
evening which potentially lasts into the day Saturday. That
said...there remains a bit of uncertainty regarding how fast this
whole system (cold front) clears the eastern Great Lakes. Given
that...have held onto low end chances for additional showers on
Saturday but it could end up being dry.

High pressure briefly builds into the Lower Lakes Saturday night
which will bring any remaining showers to and end. Dry weather will
likely last through much of the day Sunday but there is a moisture
starved cold front that approaches the region. We could see some
showers towards the end of the day but chances are low.

Overall...above normal temperatures will more than likely persist
through this entire period.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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...HSK
LONG TERM...AR
AVIATION...Apffel
MARINE...Apffel/Hitchcock