778
FXUS61 KBUF 290607
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
207 AM EDT Mon Apr 29 2024

.SYNOPSIS...
A weak frontal boundary will stall over our area today, 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 TONIGHT/...
Early this morning, a warm frontal segment will lift across
southern Ontario, which may spark a few shower across our area
as it passes by. Meanwhile a frontal boundary at the surface will
sag southward roughly to I-90 from Buffalo to Syracuse. This
will result in some fog in parts of Western NY.

The frontal boundary will remain stalled today, resulting in a
sharp temperature gradient across our region. Temperatures will
range from the lower 60s in the Thousand Islands region and
along the south shores of Lake Ontario to the lower 80s across
the Southern Tier. This frontal boundary will meander a bit,
with Buffalo likely to be notably warmer than Rochester today.

Low level convergence and instability near or just south of the
boundary will result in scattered afternoon showers and
thunderstorms across the Western Southern Tier and Upper Genesee
River Valley. Ridging aloft will limit the areal coverage.

Tonight, 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
approach our region from the northwest. Most of this activity
should hold off until after midnight, then chances for showers
will increase, especially across the Eastern Lake Ontario Region
and Niagara Frontier.

&&

.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 /06Z MONDAY THROUGH FRIDAY/...
The main concern for the 06Z TAFS will be a frontal boundary
which will sag southward across Western NY overnight. This
boundary will produce an area of LIFR cigs and fog which will
impact the KIAG/KBUF/KROC TAF sites overnight. Increasing winds
behind the front should allow for improving conditions at KART
while KJHW is likely to remain south of the influence of the
boundary. A stray shower is possible across Western NY through
11Z.

Ceilings and visibility will improve to MVFR in the 13-16Z
timeframe, and the to VFR at most locations during the
afternoon. Scattered showers and thunderstorms possible this
afternoon, but these will be in the Upper Genesee Valley and
unlikely to impact any TAF sites.

Showers will approach the area from the west tonight, with
increasing chances for rain and lowering cigs from northwest to
southeast late tonight.

Outlook...

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 today.
This will likely result in small craft conditions 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...Apffel/RSH/Thomas
NEAR TERM...Apffel/RSH/Thomas
SHORT TERM...HSK
LONG TERM...AR
AVIATION...Apffel
MARINE...Apffel/Thomas