326
FXUS61 KBUF 121838
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
238 PM EDT Sun May 12 2024

.SYNOPSIS...
A weakening area of low pressure will slowly move across our region
this afternoon, resulting in some showers. High pressure will then
move across the area bringing dry weather during the first half of
the night. A warm front will move across the area late tonight into
Monday and this will usher in a period warm and unsettled weather
which will last through Tuesday.

&&

.NEAR TERM /THROUGH MONDAY/...
A weak upper level low will gradually slide east across New England
this afternoon. Before the trough completely departs, weak surface
based instability will support some showers, and possibly an
isolated thunderstorm. The best chance for showers is in the Genesee
Valley/Finger Lakes regions. Further west, a shortwave ridge will
suppress convection and allow some breaks of sunshine.

The mid level ridge will move across the area during the first half
of the night. For those with an eye on the skies tonight, this will
provide at least a partial clearing with considerable breaks in the
cloud cover at times tonight.

Later tonight, a warm frontal segment and 40 knot LLJ will move
across the area as the ridge departs to the east. This is likely to
bring some showers with its passage late tonight and into Monday.
After this, increasing moisture and diurnal heating will result in
instability. This could also support some afternoon thunderstorms
However, the southwesterly flow will also result in drier weather
across the Niagara Frontier due to lake shadowing. Temperatures
tomorrow afternoon will be about 10 degrees warmer with highs in the
upper 60s to mid 70s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Unsettled weather will be the predominate theme during this period
with chances for showers and thunderstorms.

Monday night...there appears to be a brief lull in most of the
shower activity but still can`t say it will be completely dry
overnight. Have low end PoPs (less than 30%) for much of the region.
Closer to the frontal boundary to our north-northwest for locations
along the south shore of Lake Ontario and North Country will see the
greatest potential for showers. Overall a mild night with lows found
in the 50s for most locales.

The nearly stationary frontal boundary to our north and northwest
Tuesday will draw closer or even sag into the region. Guidance
continues to advertise several waves traversing this front which
will `potentially` bring numerous showers and thunderstorms through
Tuesday. Given that PW values will be hovering in the 1.15"-1.35"
range, and overall light flow (small MBE vectors) any convection may
produce periods of heavy rain at times. We will need to keep an eye
on this potential. As was mentioned...severe weather still looks
very limited with unfavorable shear profiles and the lack
instability. Now for temperatures...the challenge here will be the
position of the front and overall precipitation coverage. Still
thinking we will see highs in the upper 60s for most locales but
some spots could even climb into the low 70s.

Tuesday night through Wednesday...the speed and track of the
eastward advancing low will determine weather we continue to see wet
weather or a slow but gradual drying trend.

Wednesday night...still looks like there will be some lingering
showers but an overall drying trend does take place.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A progressive flow aloft will maintain chances for showers and
thunderstorms this period. Thursday may end up 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 will push eastward, likely in the Friday to
Saturday timeframe...with still a good deal of model spread to
narrow down it`s passage. Behind the trough lowering chances for
precipitation, through a secondary trough dropping out of Canada may
bring chances for showers to the North Country. Temperatures will
average above normal, especially Friday ahead of the trough, and
again on Sunday when a milder airmass begins to push northward.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Some lingering MVFR cigs and showers during this afternoon, mainly
across the Southern Tier and upper Genesee Valley. VFR elsewhere.
A mid-level ridge will move across the area this evening,
resulting in more widespread VFR flight conditions for at least
the first half of the night.

After this, a warm frontal segment will move across the area from
west to east late tonight and into Monday. This will produce some
showers, and possibly a period of MVFR cigs or vsby restrictions.
It`s associated 40 knot LLJ will also result in a period of wind
shear as it moves through.

Outlook...

Monday night and Tuesday...VFR/MVFR with the likelihood for showers
and thunderstorms.
Wednesday...Improving conditions with precipitation exiting.
Thursday...VFR.
Friday...VFR. A chance of showers late.

&&

.MARINE...
Southwesterly winds will increase following the passage of a warm
front late tonight and into Monday. Winds and waves may support
small craft headlines for Lake Erie on Monday with winds not as
strong on Lake Ontario. Otherwise, winds and waves are expected to
remain well below Small Craft conditions with just some light chop
at times through at least Tuesday.

&&

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

&&

$$

SYNOPSIS...Apffel
NEAR TERM...Apffel
SHORT TERM...AR
LONG TERM...Thomas
AVIATION...Apffel
MARINE...Apffel/JM