641
FXUS61 KBUF 140555
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
155 AM EDT Tue May 14 2024

.SYNOPSIS...
Showers associated with a passing warm front will remain along the
northern fringe of the north country through most of the night. 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/...
A frontal boundary will stall from the north shores of Lake
Ontario to the Saint Lawrence Valley overnight. Chances of
showers will linger near the boundary, while the bulk of Western
New York will be rain free. Temperatures will fall to the 50s
overnight.

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 /TUESDAY NIGHT 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 /06Z TUESDAY THROUGH SATURDAY/...
Dry weather for most locations tonight as a frontal boundary lifts
northward. Some showers will linger close to the boundary, but will
not impact any TAF sites. Mainly VFR flight conditions overnight
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...
A light southerly flow will continue through Tuesday morning ahead
of a cold front. The cold front will sink south across the lower
Great Lakes Tuesday afternoon with winds become more variable
on the lakes, before becoming northeast by Wednesday. These
northeast winds do pick up late Wednesday, but should stay
below 15 knots with some choppy contains developing, especially
on the west end of Lake Ontario. The flow turns southerly by
Friday and remains from that direction through the weekend with
conditons to remain well under headline criteria.

&&

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

&&

$$

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