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715
FXUS61 KBUF 290252
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1052 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 Lake Ontario. 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 /UNTIL 6 PM MONDAY EVENING/...
-- Changed Discussion --
As a wave of shortwave energy pushes north of our forecast
tonight...a weak cold front will sag south from Lake Ontario.
This boundary could touch off a few inconsequential showers over
the Niagara Frontier 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.
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&&

.SHORT TERM /6 PM MONDAY EVENING 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 /03Z MONDAY THROUGH FRIDAY/...
For the 00Z TAFS a cold frontal boundary sagging southward across
the region is serving as a focus for rain showers, while also
allowing for a light northeast flow that will likely produce
widespread IFR flight conditions south of Lake Ontario tonight.
While a few hours of IFR ceiling heights are likely east of Lake
Ontario along the sagging front, the concentration of fog and
lower ceiling heights will be near KBUF, KROC and KIAG. Some
patches of fog are possible in the Southern Tier including KJHW.

Ceilings and visibility will improve to MVFR in the 13-16Z
timeframe. This frontal boundary will remain draped near the NYS
Thruway tomorrow. Increasing amounts of sunshine and instability
may allow for a shower or thunderstorm towards the south. Meanwhile,
overcast skies and stable conditions to the north will maintain
likely dry conditions. Some breaks in the MVFR ceilings to VFR
tomorrow afternoon are likely for KBUF/KIAG and KROC.

Outlook...

Monday night and Tuesday...VFR deteriorating to IFR/MVFR with
showers becoming likely along with a chance of thunderstorms.

Wednesday and Thursday...Mainly VFR.

Friday...Mainly VFR with a chance of showers and thunderstorms.

&&

.MARINE...
Increasing northeast winds will result in choppy conditions along
the central and western south shores of Lake Ontario Monday. This
will result in likely small craft conditions Monday on the central
and western waters of Lake Ontario. Otherwise no significant winds
or waves are expected throughout the week...with just periodic
showers or thunderstorms a few days.

&&

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

&&

$$

SYNOPSIS...RSH/Thomas
NEAR TERM...RSH/Thomas
SHORT TERM...HSK
LONG TERM...AR
AVIATION...Thomas
MARINE...Thomas