NWS Area Forecast Discussion

000
FXUS61 KBUF 110921
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
521 AM EDT Thu Aug 11 2022

.SYNOPSIS...
A cold front will trek through the region today with chances for
showers and a couple of isolated thunderstorms. High pressure
building across the Great Lakes will otherwise yield mainly dry
conditions through Friday and into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Water vapor satellite imagery this morning depicting a deepening mid-
level trough shifting from Hudson Bay to Quebec. A cold front tied
to this trough of low pressure is crossing the lower Great Lakes and
will bring increasing cloud cover through daybreak. Patchy fog that
developed overnight in the valleys of the Southern Tier will
dissipate within a few hours of sunrise.

A few nuisance showers are expected to develop along the cold front
as it sweeps through the area today, with a couple of isolated
rumbles of thunder possible. Shower/tstorm chances will be greatest
east of Lake Ontario and across the St. Lawrence Valley in closer
proximity to the right entrance region of a +100kt H250 jet. Any
lingering showers will taper off later this afternoon as a cool and
dry airmass works in behind the front. Daytime highs will top out in
the mid to upper 70s across the region.

Expansive high pressure will build across the Great Lakes region
tonight. H850 temps dropping to +7C/+8C with shallow low level
moisture in place will be enough to generate some lake effect
clouds, with a few sprinkles possible southeast of Lake Ontario
early in the night. With a northerly flow off the lakes, overnight
lows will range from the upper 50s near the lakeshores to the upper
40s across the hilltops of the Southern Tier and North Country.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A strong mid/upper level ridge will remain parked over the central
Rockies and central High Plains Friday through the weekend, with a
downstream trough over the Great Lakes and New England. This will
maintain a relatively cool pattern across our region, with
temperatures running a little below average for the period.

Friday surface high pressure will center over the Upper Great Lakes,
with northerly boundary layer flow over the eastern Great Lakes.
850MB temps around +8C in northerly flow over the warm lake waters
will yield areas of lake effect clouds south of Lake Ontario during
the morning. By afternoon the influence of the lake will flip from
enhancing to suppressing, with morning lake effect clouds yielding
to expanding stable lake shadows south of the lakes in the
afternoon. Meanwhile, a remnant low level moisture field and cool
air aloft will support rather extensive cumulus fields across the
higher terrain south of the NY Thruway and east of Lake Ontario in
the afternoon. Highs will reach the mid 70s in most areas, around 70
on the hills.

Friday night high pressure will settle over the lower Great Lakes.
The cool/dry airmass coupled with clear skies and light winds will
promote radiational cooling, with lows dropping into the low to mid
50s on the lake plains and mid to upper 40s for the cooler Southern
Tier valleys and Lewis County. Expect some patchy river valley fog
across the Southern Tier later Friday night and early Saturday
morning.

Dry weather will continue Saturday and Saturday night as high
pressure remains over the lower Great Lakes and weakens with time.
There will be some increase in mid/high clouds from west to east
later Saturday and Saturday night ahead of a shortwave and surface
low moving into the upper Midwest. Temperatures will warm nicely
Saturday after a cool start, with highs in the 75-80 degree range in
most locations.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The western ridge/eastern trough pattern across North America will
continue through next week with heat in the west and relatively cool
temperatures in the east. A series of shortwaves will move through
the eastern trough Sunday through early next week, eventually
supporting the development of a mid level closed low over New
England or southeastern Canada by Wednesday. Models show some
divergence with the evolution of the pattern and placement of the
closed low by this time, with forecast confidence of day to day
details lowering with time next week.

Sunday, weak low pressure will move from southern Lake Michigan into
the Ohio Valley, weakening with time. The GFS remains faster and
stronger with this feature and subsequent rain chances than the
ECMWF/GEM. With this in mid, maintained a low chance of showers
across Western NY Sunday and Sunday night, with a dry forecast for
the North Country.

Monday and Tuesday several more shortwaves will cross the Great
Lakes, with each feature supporting a chance of a few showers at
times. A closed low is then forecast to evolve somewhere over the
Northeast by Wednesday. A farther south and west closed low (ECWMF)
would keep a greater chance of rain in our area, while a farther
northeast closed low position (GFS,GEM) would bring lower rain
chances. Given the uncertainty, continued with chance POPS for now.
Temperatures will run a little below average during the early to mid
week period.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
VFR cloud cover is increasing from the northwest along an
approaching cold front this morning. Patchy fog in the Southern
Tier valleys may encroach on the KJHW airfield for a period
before fog dissipates within a couple hours of sunrise.

The aforementioned cold front will move across the area today. This
will mainly result in clouds with bases around 4-5k feet, though a
few scattered showers may develop along the front, with greatest
chances east of Lake Ontario including KART. A couple of isolated
thunderstorms may develop across the North Country which will be in
closer proximity to the right entrance region of a +100kt 250mb jet.

Any lingering showers will end by mid-afternoon, with VFR flight
conditions expected as clouds scatter out at most locations.

Outlook...
Thursday night...VFR.
Friday through Saturday...VFR.
Sunday...Mainly VFR. Chance of a shower or an isolated
thunderstorm.
Monday...Mainly VFR. Chance of showers and thunderstorms.

&&

.MARINE...
A cold front will pass through the region today with a strengthening
northwest breeze. Winds and waves may approach SCA criteria with a
moderate chop building along the southern shores of the lakes by
this afternoon and evening respectively.

&&

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

&&

$$

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

NWS BUF Office Area Forecast Discussion