128
FXUS61 KBUF 121021
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
621 AM EDT Wed Jun 12 2024

.SYNOPSIS...
Notably warmer weather is on the horizon as temperatures will climb
back towards normal today, then reach well above normal on Thursday.
While a cold front will bring chances for showers and put the brakes
on our warm up for Friday and Saturday, mid summer warmth is
guaranteed for early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A broad area of surface high pressure will slowly drift east of the
Great Lakes today and ensure quiet, warmer weather. There will
be some nuisance cloud cover to contend with as a weak upper-
level low over New England moves to the Canadian Maritimes and
an upstream mid-level shortwave moves across southern Ontario
later this morning and afternoon. The stubborn deck of stratus
courtesy of the cool airmass around the former continues to
linger across the Finger Lakes region and North Country early
this morning, while mid and high cloud cover continues to
increase across the western zones with the approach of the
latter. Partial clearing between the two features overnight has
allowed for a few areas of fog to develop across western NY,
especially down in the Southern Tier valleys.

While the fog across WNY should burn off within an hour or two
of sunrise and the skies should begin clearing out by late
morning, BUFKIT soundings indicate the lower hanging cloud cover
across the eastern zones not lifting and eroding away until
this afternoon. An isolated shower or sprinkle also can`t quite
be ruled out in these areas as the shortwave trough moves
through. Otherwise, temperatures today should be rather
pleasant, being some 5-10 degrees warmer than yesterday with
highs in the lower 70s, slightly cooler across the North Country
where the clouds are expected to linger.

High pressure will migrate off the East Coast tonight as an area of
deepening low pressure moves across southern Ontario. While the
forecast area will remain dry overnight under partly to mostly clear
skies...A tightening pressure gradient between the two features will
cause south-southwesterly flow to deepen, leading to warmer
overnight temperatures. Lows will bottom out in the low 60s across
far western NY and the upper 40s/low 50s across the higher terrain
of the North Country, with a range of 50s in between.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The pattern will amplify again across North America Thursday through
Friday, allowing a mid level trough to dig through Ontario and
Quebec, with the southern edge of the trough crossing the Great
Lakes and New England.

Thursday, a thermal ridge will briefly build into the eastern Great
Lakes just ahead of the trough. This will allow temperatures to
climb well into the 80s, along with an increase in humidity. There
will be some increase in clouds by afternoon, but most areas should
stay dry as warm air aloft provides capping and holds down the
chance of deep moist convection despite increasing diurnal
instability.

Thursday night through Friday, DPVA and height falls will spread
large scale ascent across the eastern Great Lakes in advance of the
trough. An associated cold front will approach Thursday night, then
cross the area early Friday. Forcing and a narrow axis of deeper
moisture along and ahead of the trough axis will support a few areas
of showers and scattered thunderstorms ahead of the advancing cold
front Thursday night through early Friday. Poor timing relative to
the diurnal cycle and generally weak forcing will keep the chance of
stronger convection low. Rain chances will end from northwest to
southeast through the day Friday as drier and more stable air
arrives behind the cold front.

Surface high pressure will build into the Great Lakes Friday night,
with associated dry air and subsidence allowing for a return to dry
weather and partial clearing. The arrival of a cooler/drier airmass
will allow temperatures to drop back into the low to mid 50s in most
areas, with 40s for some of the Southern Tier valleys and North
Country.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The main story through the long term portion of the forecast will be
building heat and humidity next week.

The brief trough incursion over the Northeast Friday through
Saturday will quickly fade as the longwave pattern across North
America flips. A Pacific trough will move into the western CONUS
early next week, forcing a strong downstream ridge to build across
the central and eastern CONUS. The building ridge, along with
persistent southwest low/mid level flow will pump heat and humidity
into the Ohio Valley and New England starting Monday, and lasting
much of next week.

Relatively cool temperatures Saturday (highs in the upper 60s to
lower 70s) will give way to mid-summer heat by Monday. Highs Monday
through Tuesday will likely reach the lower 90s for lower elevations
away from lake influences as 850MB temps climb to around +20C. The
heat will likely last most of next week given the strength and
breadth of the ridge. A southwest flow will likely keep the Buffalo
area a little cooler most days, with the Rochester area into Central
NY most likely to see numerous days of 90+ degree temperatures.
Dewpoints will move upward into the 65-70 range with time, bringing
a notable heat index by early next week.

The westerlies will remain north and west of the area early next
week, keeping the chances of convection low Monday through Tuesday
with warm temperatures aloft likely providing an effective cap.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
Mainly VFR conditions across the region for the 12z TAF cycle as
surface high pressure slowly moves east of the Great Lakes.

Stubborn deck of low VFR stratus east of KROC as of 11z will
continue to slowly lift and erode today. Partial clearing west of
this stratus deck has allowed patchy fog to develop early this
morning. Fog is most widespread down in the Southern Tier valleys
(KJHW), though localized fog has also formed in the vicinity of
KROC. Vsbys at these terminals should quickly improve after about
12z.

Partly to mostly clear VFR skies by this evening will persist
through tonight, with just passing mid and high clouds at times.

Outlook...

Thursday...VFR. Breezy southwest winds with gusts to 30kts possible
at KIAG and KBUF.
Thursday night and Friday...VFR/MVFR. Showers and thunderstorms
likely.
Friday night through Sunday...VFR.

&&

.MARINE...
High pressure will build across the Lower Great Lakes resulting in
light winds which will last through tonight.

A cold front will then move across the Lower Great Lakes late
Thursday night and early Friday. Southwest winds will increase ahead
of the front Thursday, with winds remaining elevated through Friday.
This will bring choppy conditions to both lakes. High pressure will
then build back across the waters with light winds and generally
favorable boating conditions during the weekend.

&&

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

&&

$$

SYNOPSIS...PP/RSH
NEAR TERM...PP
SHORT TERM...Hitchcock
LONG TERM...Hitchcock
AVIATION...PP
MARINE...Apffel/PP