163
FXUS61 KBUF 060845
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
445 AM EDT Mon May 6 2024

.SYNOPSIS...
A cold front will exit the eastern Lake Ontario region this morning,
with showers coming to an end. Early morning fog and low clouds will
give way to partly sunny skies today as high pressure builds into
the region. Dry weather will last through Tuesday before a warm
front crosses the region Tuesday night through early Wednesday with
a chance of showers and thunderstorms. Unsettled weather will then
last the rest of the week as a trough of low pressure slowly crosses
the Great Lakes.

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold front will move east of the area by mid morning. An area of
showers east of Lake Ontario early this morning will exit to the
east by mid morning. Areas of low stratus and fog will continue
through early morning. Most of the fog is being driven by advection
as a warm/moist airmass crosses the cold lakes. Fog will be most
prevalent east of Lake Erie and Lake Ontario. Much drier air is
poised just upstream across southern Ontario, and forecast soundings
show low level moisture rapidly depleting around daybreak. Expect
quick improvement around daybreak in most areas, with fog lasting
the longest across the western Southern Tier and near the east end
of Lake Ontario.

Once the fog and low stratus dissipates, high pressure building into
the Great Lakes will bring a return to dry weather. A fair amount of
cirrus will stream across the region today downstream of a mid level
trough drifting east across the Ohio Valley. This will yield partly
sunny skies in most areas today as sunshine filters through the high
clouds. Temperatures will continue to run a little above average,
with highs in the 65-70 degree range. Light northwest flow will keep
the southern and eastern shores of Lake Ontario much cooler.

Tonight high pressure will drift east from the Great Lakes into
Ontario and Quebec, maintaining dry and quiet weather across our
region. Extensive cirrus in the evening will clear overnight. The
mainly clear skies and light winds will allow for strong radiational
cooling, with lows in the low to mid 40s in most areas.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Tuesday, a weakening ridge and an elongated sfc high stretching into
the region from Canada will provide for mainly fair weather for the
day. A few scattered showers/sprinkles may reach far sw NY by the
late afternoon. Above normal temperatures will continue with
afternoon highs reaching the low to upper 70s for most areas, except
the higher terrain east of Lake Ontario where afternoon temperatures
will reach the mid 60s.

Tuesday night, a few different weak sfc lows and shortwave troughs
will traverse along a weakening occluded front that is tracking east
across the Great Lakes and Ohio Valley by this time. As these
features track toward the region Tuesday night, shower potential
will increase from southwest to northeast through the night across
the entire forecast area. A few embedded thunderstorms will also be
possible with these showers as there will be some instability,
mainly south of I90. This scenario is similar in some ways to the
setup earlier this past weekend with an occluded front and the
models bringing in more rain than what occurred. Models are starting
to come in a little drier overall for the Tuesday night into
Wednesday time frame, so will need to keep an eye on how the models
handle things. Showers should mostly be done by around daybreak for
the western third of the forecast area, with increasing shower
potential toward the east during the a.m. commute.

Wednesday, showers will linger through most of the morning for the
eastern Lake Ontario area before tracking east, and out of the area.
Wednesday is starting to look a little drier for most areas during
the day with WNY remaining mostly rain free and the eastern half of
the forecast area only having a few scattered showers/sprinkles
during the afternoon. A bit cooler for the day with highs in the low
60s for the higher terrain east of Lake Ontario to the mid 70s for
the lower elevations south of I90.

Wednesday night, shower potential increases later in the night as an
area of low pressure develops over the mid-Mississippi Valley ahead
of a trough and tracks toward the region. Showers will track once
again from southwest to northeast through the second half of the
night. Some guidance is pushing better organized shower activity
farther south and across Pennsylvania, so will need to see how that
evolves.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The sfc low from Wednesday night will continue to strengthen and
increase in size as a trough amplifies over the central CONUS and as
a few rounds of vorticity advection move through the trough.

As the trough moves east and the main sfc low tracks ahead of it, a
mid level low will develop over the eastern Great Lakes. The
combination of the sfc & mid-level low will cause showers to cover
most of the forecast area for Thursday into Friday. Showers will
mostly taper off from west to east late Friday afternoon into the
night as the sfc low tracks east. However, some lingering showers
will be possible Saturday morning, especially east of Rochester with
a cyclonic flow lingering over the northeast. An incoming ridge for
later Saturday will eliminate any remaining showers that may exist
across the area.

Another trough dropping southeast out of Canada and across the Great
Lakes will increase the shower potential starting Saturday night,
BUT there is still very much uncertainty among the models as to
track and timing of showers associated with the system. Currently
going with chance for showers for most of Sunday, but that can
certainly change either way.

Temperatures for the long term period will generally be near normal
for most of the period, except for Friday, which still looks cooler
than normal.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A cold front will exit the eastern Lake Ontario region by mid
morning, with showers mainly east of Lake Ontario coming to an end.

The bigger impact will be fog and low stratus through early to mid
morning with areas of IFR/LIFR. Most of the fog is being driven by
advection, with a warm/moist airmass crossing the cold lake waters.
Off Lake Erie, the current area of fog directed towards KBUF/KIAG
will continue for a few more hours before moving south into the
western Southern Tier (including KJHW) by daybreak. Forecast
soundings show drier air quickly arriving at KBUF/KIAG by around 09Z
with quickly improving conditions for the busy morning push. The fog
will last through 12-13Z at KJHW before improving.

Some fog and low stratus will also form over and east/southeast of
Lake Erie through early morning, with some of this possibly
impacting KROC and KART briefly.

All of the fog and low stratus will scatter out by mid morning as a
much drier airmass moves into the eastern Great Lakes behind the
departing cold front. VFR will then prevail for the rest of today and
tonight with areas of cirrus.

Outlook...

Tuesday...VFR.

Tuesday night and Wednesday...VFR/MVFR. A chance of showers and
thunderstorms.

Thursday...VFR/MVFR. Showers likely with a chance of thunderstorms.

Friday...MVFR. Showers likely.

&&

.MARINE...
Negligible winds and waves will continue through Wednesday. There
will be some marine layer fog over Lake Erie and Lake Ontario
through early to mid morning as a warm/moist airmass overlays the
cold lake waters. A much drier airmass will move into the area
today, ending the marine layer fog.

&&

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

&&

$$

SYNOPSIS...Hitchcock
NEAR TERM...Hitchcock
SHORT TERM...SW
LONG TERM...SW
AVIATION...Hitchcock
MARINE...Hitchcock