304
FXUS61 KBUF 132345
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
745 PM EDT Mon May 13 2024

.SYNOPSIS...
Showers associated with a passing warm front will move across the
north country through this evening with some thunderstorm also
possible. This front will usher in a period warm and unsettled
weather which will last through the middle of the week. After this,
a weak high pressure ridge will provide warm and mainly rain-free
weather outside of a few afternoon showers.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
Showers are found mainly across the eastern Lake Ontario area
currently, as a warm front pushes northeast across the region.
Showers will push north to the St. Lawrence Valley through the
evening. Current temperatures across the area are in the upper 60s
to low/mid 70s for most areas. The warmest temperatures are behind
the passing warm front, generally across WNY. Some cooler
temperatures down to the low 60s can be found in areas where showers
are in place.

The warm front will stall from the north shores of Lake Ontario
to the Saint Lawrence Valley tonight. Chances of showers will
linger near the boundary, while the bulk of Western NY will be
rain free. Temperatures will fall to the 50s tonight.

The frontal boundary to the north will slowly sag southward
during the day Tuesday. Limited diurnal instability will develop
across Western NY, with showers and a few thunderstorms
developing Tuesday afternoon. The greatest coverage will be
south and east of Lake Ontario with slightly lower chances on
and along its immediate shorelines. Precipitable water values
nearing 1.25" not too far above climatological normals, but weak
flow aloft will result in slow storm motion. The potential
exists for repeated rainfall which could be heavy at times with
any convective activity. Modest PWAT values lower the risk for
flash flooding, but the risk is non-zero.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
A 500 hPa trough will pass across the Ohio Valley and the mid-
Appalachians Wednesday and Wednesday night. While most of the
showers associated with this feature will be to our south, there
will be a easterly flow of Atlantic moisture into our region that
will bring scattered showers through the day Wednesday. Highest
chances for showers will be to our east, closer to the deeper
Atlantic moisture, but also along a convergent boundary. This
boundary, southeast flow around the trough aloft, and northeast flow
from a incoming area of high pressure, will serve as a boundary for
likely PoPs through the afternoon, and into the evening hours. The
light flow could lead to some patches of fog Wednesday night in
areas where daytime rain occurred.

Highs Wednesday will reach towards 70 near the Lakes, while inland
and under deeper moisture and rain showers...mid 60s. Temperatures
at night will dip down into the mid 50s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
A progressive flow aloft with impulses and shortwaves rippling
through will maintain chances for showers and thunderstorms this
period, with the best chances for showers and even a rumble of
thunder Friday night and Saturday with a trough passage.

To start this period, Thursday will be mostly dry, with low PWATS
and a narrow ridge of high pressure nearby...this between an east
coast low, and trough across the Plains. However there is a
possibility that a few showers from the east coast low sneak far
enough westward into our eastern CWA.

This western trough, and its additional lift, will push eastward,
likely in the Friday night to Saturday timeframe. Will place likely
PoPs with the trough passage, along with a slight chance for thunder
with MUCAPE values around 500 J/KG ahead of the trough. Behind the
trough lowering chances for precipitation, through a secondary
trough dropping out of Canada may bring chances for showers Sunday.
Temperatures Thursday through Saturday will average just above
normal, and then the final two days of this period, Sunday and
Monday will be even warmer with a milder airmass pushing northward.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Showers with the potential for a few embedded thunderstorms this
evening are found mainly east of Lake Ontario along a warm front
that will track north and east of the region this evening. Overall
widespread VFR flight conditions, except localized MVFR possible in
vsby restrictions in any showers or thunderstorms.

Dry weather for most locations tonight as the frontal boundary
lifts northward. Some showers may linger near KART which will be
closest to the boundary. Mainly VFR flight conditions for
tonight through Tuesday morning. Chances for showers and a few
thunderstorms increase with instability Tuesday afternoon.
Mainly VFR with localized IFR in heavier showers and
thunderstorms.

Outlook...

Tuesday night...MVFR/IFR in showers, stratus, and fog.

Wednesday...MVFR/IFR with a chance of showers, along with
lingering stratus. Improving later Wednesday and Wednesday night.

Thursday...VFR.

Friday...VFR. A chance of showers late.

Saturday...VFR/MVFR. A chance of showers.

&&

.MARINE...
Moderate southwesterly flow today, but winds will be strongest
on the land due to lake breeze enhancement. Winds on the waters
expected to remain below Small Craft criteria. After this, there
will be a relatively weak flow, with winds expected to remain below
15 knots through Friday.

&&

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

&&

$$

SYNOPSIS...Apffel/SW
NEAR TERM...Apffel/SW
SHORT TERM...Thomas
LONG TERM...Thomas
AVIATION...Apffel/SW
MARINE...Apffel