-- Discussion containing changed information from previous version are highlighted. --
968
FXUS61 KBUF 301857
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
257 PM EDT Tue Apr 30 2024

.SYNOPSIS...
A slow moving cold front will make its way across the region this
afternoon and evening while generating some showers and possibly a
thunderstorm or two. The highest chance for thunderstorms will be
east of the Genesee valley. Fair dry weather will then return
tonight and persist through at least Friday morning. Meanwhile...
temperatures will remain solidly above normal for the foreseeable
future.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
A negatively tilted mid level trough will exit the Upper Great Lakes
to central Ontario this afternoon...while an associated cold front
will slowly cross our forecast area through the first half of
tonight. A 60 mile wide band of generally light showers will move
across the region during the remainder of the afternoon. The
exception will be across the IAG Frontier where the showers are
already in the process of tapering off.

The showers will become more widespread east of the Genesee valley
where...with the help of some diurnally induced instability...there
may even be a few thunderstorms. The greatest chance for any storms
will be over the Finger Lakes region and points east where there
will be a small risk for some stronger storms that could generate
locally heavy rain and wind gusts to 45 mph. Otherwise...basin
average rainfall will be UNDER a tenth of an inch or less.

The showers will continue to taper off from west to east later this
afternoon and early evening. While the showers will come to an
end...a light flow aloft will enable much of the cloud cover to
persist for the greater part of tonight. The exception to this will
be across the Southern Tier where clearing seen on VSB/IR imagery
over northwest Ohio should make its way into the area.

The clearing will continue Wednesday morning...as a progressive mid
level shortwave ridge and associated weak sfc high will cross our
forecast area. The fair dry weather on Wednesday will be
accompanied by max temps that will range from the mid 60s across the
Eastern Lake Ontario region to the low and mid 70s over the western
counties.

A compact shortwave will pass by to our north Wednesday night. This
will drive a moisture starved cold front through our region. While
there will be slgt to low chc pops near and east of Lake Ontario...
the passage will be marked by nothing more than patchy clouds and
subtle wind shift to mark the occasion.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
The period will start out mostly dry as a ridge builds into the
region from the west on Thursday. There may be a few showers across
the north country as weakening sfc low and trough pass by the area
on Thursday morning. Dry weather is expected through most of Friday
afternoon before an area of showers approaches from the west.

A large occluding sfc low tracking northeast into western Ontario
from the upper Midwest on Friday into Saturday will push a cold
front toward the region late Friday. A new weaker sfc low will
develop over the Tennessee/Ohio Valleys and track northeast along
the cold front. Showers will increase from west to east later Friday
into early Saturday as the cold front and secondary sfc low track
toward the area, along with the warm front of the secondary sfc low.
Some embedded thunderstorms will be possible as the warm sector with
the sfc low moves over the region. Still some timing differences
among guidance with slower guidance around 3 to 6 hours slower than
some of the faster guidance. Rainfall through Saturday night should
range from a few hundredths of an inch for the north country to a
few tenths of an inch for far western NY.

Temperatures during the period will warm to well above normal with
highs on Thursday in the upper 50s to low 70s. Fridays high
temperatures will reach at least 15 degrees above normal, warming
into the mid 60s to near 80 for the day. Some uncertainty for
Thursday temperatures as some guidance has come down a bit on maxT`s
across the area, due to slower warm air advection, so made some
adjustments down, but still a warm day.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
A vertically stack low pressure system located over NW Ontario
Canada will slowly drag a cold through the eastern Great Lakes. Due
to the slow progression of this front, and then a potential
secondary front have kept low end PoPs across much the the forecast
area into Sunday. We should see a fairly widespread area of rain
Saturday move from west to east, which then gives way to chances for
showers into Sunday. Brief surface high pressure builds into the
Great Lakes Sunday night, causing any lingering showers to gradually
deplete from west to east.

Dry weather looks to persist through much of Monday but yet again
another warm frontal boundary will begin to approach from the
southwest. This will introduce a chance of shower either late Monday
night or during the day Tuesday. Still some timing issues to work
out but have once again added chance PoPs reflecting the front
nearing and entering the region.

Overall, temperatures will continue to remain above average through
the weekend and into next week.
-- End Changed Discussion --

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
MVFR to IFR cigs across far western New York early this afternoon
will give way to VFR weather towards this evening. Meanwhile...a
swath of light to occasionally moderate shower activity will push
east across the remainder of the region. Cigs will drop to IFR
levels as this pcpn moves through.

As we work through tonight...VFR weather will return to the Southern
Tier. For the majority of the region though...a period of VFR
weather will once again give way to IFR cigs as we work through the
overnight.

On Wednesday...IFR to MVFR cigs in the morning will give way to VFR
weather regionwide.

Outlook...

Thursday...VFR.
Friday...Mainly VFR with a chance of afternoon showers and
thunderstorms.
Saturday...MVFR to VFR with showers likely and possible
thunderstorms.
Sunday...Morning showers otherwise mainly VFR weather.

&&

.MARINE...
A quiet week is expected on the lower Great Lakes as the pressure
gradients remains weak. Winds will generally remain 15 knots or
less. There will periodic showers or thunderstorms today before
dry weather returns for the mid week period.

&&

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

&&

$$

SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...SW
LONG TERM...AR
AVIATION...RSH
MARINE...TMA