818
FXUS61 KBUF 291031
AFDBUF

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

.SYNOPSIS...
A 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 may 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 showers across the
Eastern Lake Ontario region as it passes by. Meanwhile a
frontal boundary at the surface will sag southward roughly to
I-90 from Buffalo to Syracuse.

The frontal boundary will remain stalled today, resulting in a
sharp temperature gradient across our region. Temperatures will
range from the upper 50s to 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/...
Mid-level ridge axis will lie across the Northeast into the Mid-
Atlantic while the next trough pivots across the Great Lakes Tuesday
morning. Meanwhile at the surface, a cold front will extend from the
Georgian Bay to central Lake Erie and into central Ohio. A good
majority of western New York and the Finger Lakes region will lie
within the warm sector, while the North Country/Saint Lawrence
Valley will remain on the cool side of the warm front. This being
said, the combination of increasing moisture along with the
approaching front will support rain showers and a few rumbles of
thunder to enter the area by day break Tuesday. As the day
progresses, chances for showers and thunderstorms will push from
west to east with the best chances for thunderstorms will lie across
the interior portions of the forecast area where diurnal heating
will support the increased probability. The risk for severe storms
Tuesday continues to remain low due to the early timing of the
frontal passage, and thus resulting in most of the convection to lie
east of the area. Additionally, any thunderstorms will be capable in
producing some heavy rainfall due to anomalously high PWAT values
for late April.

The front will then move east of the area Tuesday night, causing
showers to diminish across the North Country Tuesday evening. Then,
mostly dry weather is expected across western New York overnight.

Surface high pressure will then push across the region Wednesday
through Thursday supporting dry weather for the middle portion of
this week. Temperatures will remain above normal for early May, with
highs in the 70s each day and cooler conditions along the shorelines
of the Lakes.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
The next surface low will be in the midst of passing northeast
across the Upper Great Lakes into Ontario, Canada Thursday night.
While surface high pressure will lie across the region Thursday
night into Friday, the aforementioned low pressure will support a
warm front to sweep north across the Great Lakes. While this frontal
passage may bring a few showers to the region, the forecast area
will primarily remain dry Thursday night through Friday.

As this front continues to exit northeast, its associated surface
cold front will cross from west to east across the Great Lakes
Friday night through Saturday night. There continues to remain some
uncertainty with the exact timing and therefore held PoPs to just a
chance for now.

Brief surface high pressure will then slide across the Great Lakes
Sunday, causing any lingering showers to gradually deplete from west
to east.

Overall, temperatures will continue to remain above average through
the end of the week and into the weekend.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
The main concern for the 12Z TAFS will be a frontal boundary
which will sag southward across Western NY. There will be some
fog and areas of IFR or lower cigs near this boundary.

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 cigs lowering to 3-4k feet from
west to east 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,
where Small Craft headlines were issued. Winds will diminish
tonight. 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...Small Craft Advisory until 11 PM EDT this evening for LOZ042.
         Small Craft Advisory until 8 PM EDT this evening for
         LOZ043.

&&

$$

SYNOPSIS...Apffel/RSH
NEAR TERM...Apffel/RSH
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...Apffel
MARINE...Apffel/Thomas