454
FXUS61 KBUF 110547
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
147 AM EDT Sat May 11 2024

.SYNOPSIS...
Cool and unsettled weather will remain in place through the weekend.
Mostly cloudy conditions with a chance of showers will persist
across north central NY overnight through Saturday. Further west,
dry conditions will turn wet as a cold front moves through the
region Saturday afternoon. A few thunderstorms are possible Saturday
afternoon into Saturday evening. Showers will linger across
the region Saturday night into Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Satellite imagery shows mostly clear skies with patchy valley fog
across western NY late tonight. Quite the opposite on the east side
of the forecast area with clouds and showers east of the Genesee
Valley into the North Country.

While a progressive shortwave ridge will cross the Lower Great
Lakes. This scenario will be accompanied by a wedge of dry mid level
air that will bring an end to the rain in most areas while promoting
some clearing...mainly over the western counties. A ribbon of
vorticity along an inverted trough may bring an uptick in shower
activity toward daybreak east of Lake Ontario.

A robust shortwave and attendant sfc low will dive southeast across
the Upper Great Lakes on Saturday. A swath of deep moisture ahead of
this system will push across the western counties during the midday
and afternoon...then across the Eastern Lake Ontario region late in
the day and Saturday night. The resulting lift supplied by moderate
hgt falls...low level convergence and being in the proximity of the
left front quad of a nominal 90kt H25 jet with this scenario will
prompt a renewal in shower activity as the day matures. There could
even be a thunderstorm over the western counties.

The most widespread and persistent shower activity will be over the
western counties during the afternoon. Dry weather with some
sunshine can even be expected for the Finger Lakes before conditions
deteriorate. It will remain cool...as temperatures on Saturday will
top out within a few degrees of 60.

Showery weather will then linger through much of Saturday night...as
the core of a H5 low with its -24c temps will pass directly across
our region.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Shower will slowly diminish from west to east Sunday as the mid-
level low exits off to our southeast. Overcast skies will then
overtime begin to break up revealing some sunshine by late Sunday
afternoon. Otherwise...a cool day will be felt with highs in the
upper 50s across the higher terrain to low 60s.

Sunday night...shortwave ridge briefly builds in which should
deliver dry weather for much of the overnight hours. The next
feature of interest will be an occluded front approaching the
eastern Great Lakes from the northwest early Monday morning. This
boundary will slowly ooze into the forecast area with showers
becoming `likely`, and the potential for some rumbles of thunder. It
will not be quite as cool Monday with temperatures peaking in the
upper 60s to low 70s.

Monday night...this is where the forecast gets a bit more murky in
regards to the progression of the front through the region. It will
all depend on the interaction of a mid-level low spinning over the
Midwest and another low located over James Bay. At this
point...there are various model solutions ranging from very wet(GFS)
weather to it turning progressively drier by the middle of the week.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A closed mid-level low centered over the Hudson Bay Tuesday morning
will gradually rotate eastward into Wednesday. Meanwhile, ridging to
the west across the Upper Midwest and western Great Lakes Tuesday
night will build across the remainder of the Great Lakes into Friday
morning before the next trough dives southeast across the Central
Plains Friday.

Overall, with the mid-level closed low to the north of the area
Tuesday, its associated surface low over Quebec will support a cold
front to finish pushing southeast across the area Tuesday,
supporting widespread rain and a few rumbles of thunder to pass
across the area. Chances for showers will then continue across the
area Tuesday night through Wednesday due to the troughing overhead.

As the aforementioned mid-level ridging pushes east across the Great
Lakes, associated surface high pressure will also move into the
eastern Great Lakes, resulting in a period of dry weather Wednesday
night thorugh much of Thursday.

The next chance for showers will return Thursday night through
Friday as warm front approaches the area.

Expect a gradual warming trend throughout much of next week, with
subtle warming each day. By the end of the week the temperatures
will have rebounded to slightly above normal.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Mainly VFR conditions across western and north central NY late
tonight. Valley fog is developing across interior portions of the
western Southern Tier and Finger Lakes region and IFR conditions may
reach KJHW late tonight into Saturday morning. Further northeast,
ceilings should stay above 5k feet at KART overnight, however nearby
sites (KGTB) closer to the Tug Hill are MVFR.

A cold front will approach the region Saturday. Regional radar shows
an area of showers and thunderstorms across Lower Michigan late
tonight. This activity will likely expand as it moves into western
NY Saturday afternoon. Additional showers will develop across north
central NY Saturday ahead of the front. VFR conditions will
deteriorate as showers move into western NY Saturday afternoon.
Widespread MVFR conditions are most likely with IFR conditions
across the higher terrain including KJHW late Saturday evening. VFR
conditions will likely remain at KART for much of Saturday. Flight
conditions will likely become MVFR late Saturday evening.

Outlook...

Saturday night...MVFR cigs with showers gradually diminishing in
coverage.
Sunday...VFR to MVFR CIGS with scattered showers.
Monday and Tuesday...VFR/MVFR with the likelihood for showers and
possible thunderstorms.
Wednesday...Improving conditons with precipitation exiting.

&&

.MARINE...
Mainly light, variable winds (less than 10 knots) will be the rule
through the most of the weekend, before a more pronounced
southwesterly flow (10-15 knots) develops ahead of a warm front
approaching from the west toward the tail end of the weekend.

&&

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

&&

$$

SYNOPSIS...HSK
NEAR TERM...HSK/RSH/SW
SHORT TERM...AR
LONG TERM...EAJ
AVIATION...HSK
MARINE...JM/TMA