745
FXUS61 KBUF 120744
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
344 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, mostly dry, and warmer weather.
There will be a few minor nuisances to contend with as a weak upper-
level low over New England moves to the Canadian Maritimes and an
upstream mid-level shortwave moves out of Michigan then tracks
across our area 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 fog to
develop across the Southern Tier, especially down in the valleys.

As the shortwave to the west moves through today, expect partly to
mostly cloudy skies with a couple of isolated showers or sprinkles
possible. While WNY should begin to clear out by late morning,
BUFKIT soundings indicate the lower hanging cloud cover across the
eastern zones not eroding away until later this afternoon.
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 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 /08Z WEDNESDAY THROUGH SUNDAY/...
Mainly VFR conditions across the region for the 06z TAF cycle as
surface high pressure slowly moves east of the Great Lakes.

Stubborn deck of low VFR/MVFR stratus from about KOLE to KSDC as of
06z will continue to slowly erode and shrink eastward through the
pre-dawn hours. This partial clearing will allow localized fog to
develop down in the Southern Tier, which is expected to impact KJHW
through about 12-13z.

Widespread VFR is expected from KROC westward through the day
Wednesday, with some lingering low VFR/MVFR cloud cover across the
Finger Lakes and North Country. These should then clear out by
Wednesday evening with mainly clear skies overnight.

Outlook...

Thursday...VFR.
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