960
FXUS61 KBUF 131351
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
951 AM EDT Thu Jun 13 2024

.SYNOPSIS...
Temperatures will trend warmer today with highs in the 80s. A
passage of a cold front tonight will support some showers and
possible thunderstorms into Friday along with cooler conditions.
Mid summer heat and humidity will take hold for early next week when
apparent temperatures will soar into the 90s.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Weak mid level ridging will be over the region today...as surface
high pressure will remain along the East Coast. This will result in
a southerly low-level flow advecting in a warmer air mass with 850
mb temperatures rising to around +15C. This along with sunshine
through high clouds will support afternoon temperatures in the lower
to mid 80s.

An upper-level trough and slow moving cold front will work into the
region tonight. This will bring some showers and possibly a few
thunderstorms. Rainfall amounts should average from a quarter to a
third of an inch along and north of the Thruway, tapering to
less than a tenth of an inch along the western Southern Tier.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Surface low pressure initially across eastern Quebec will shift
northeast into Labrador through the course of the day Friday. The
system`s elongated cold front will gradually sag southward through
the eastern Great Lakes as it does so, with the greatest threat for
showers and a few storms moving in tandem just out ahead of the
boundary. A lingering convective wave moving out of the Ohio Valley
will likely move into the region and ripple along the front Friday
morning, slowing its progress while causing a few moderate to
locally heavy showers and/or thunderstorms to blossom across
portions of the Southern Tier and western Finger Lakes region. While
the steadier shower activity should be mainly southeast of the
forecast area by the afternoon, diurnal heating and residual
moisture ahead of the system`s parent upper level trough axis could
cause a few additional lighter showers or an isolated thunderstorm
to redevelop across western NY. Chances for this look to be slightly
better up in the North Country where a weak secondary shortwave will
move through, though subtle differences in the timing of the upper
trough axis are noted among the latest 00z suite of guidance so will
shy away from higher PoPs at this juncture. Otherwise, the cold
front will knock daytime temperatures back to near normal values
Friday with highs in the low to mid 70s, a few readings in the 60s
across the hilltops.

A strong ridge of high pressure at all levels will build back across
the Great Lakes in the wake of the trough Friday night. The center
of the surface high should move directly overhead by Saturday night,
then shift east and migrate off the East Coast by the end of the day
Sunday. This will result in dry, tranquil weather across the
forecast area through the weekend with pleasant temperatures. Highs
Saturday will be on the cooler side mainly in the upper 60s to low
70s as the region remains within the post-frontal airmass. With the
onset of warm air advection on the backside of the high Sunday,
temps should top out in the upper 70s to low 80s with low humidity.
Nighttime lows Friday and Saturday night will be cool, dipping into
the 50s across the lower terrain and mid/upper 40s across the
interior of the Southern Tier and North Country.

While the weekend will feature superb weather for outdoor
activities...It will also present the perfect opportunity for
anyone who has yet to put in their AC units to finally do so
BEFORE the heat and humidity surges next week. More on that in
the long term section below.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
...Headline Worthy Summer Heat Expected This Period...

The longwave pattern across the CONUS next week will be dominated by
broad troughing west of the Rockies and an expansive ridge across
the east. This ridge is expected to become abnormally strong, with
overhead 500mb heights potentially climbing to near 600dm (2-3SD
above normal compared to climatology) by the middle of the week. The
resultant Bermuda High will anchor itself over the western Atlantic,
with deep anticyclonic flow around the high causing a warmer airmass
to surge across the eastern CONUS. 850H temps over the forecast area
within this airmass are expected to quickly reach or exceed +20C by
Monday and stay within this range through the remainder of the 7 day
forecast, and potentially beyond.

In terms of sensible weather, what this will translate to at the
surface will be a prolonged stretch of oppressive summer heat and
humidity. Daytime temperatures Monday will feature widespread upper
80s and lower 90s, though remaining a bit cooler across the North
Country with low/mid 80s where a slightly cooler airmass will
linger. By Tuesday and Wednesday, widespread high temperatures in
the low to mid 90s are expected, hottest in the interior valleys and
coolest just northeast of both lakes (including the Buffalo area) as
a persistent southwest flow advects cooler marine air off the lakes.
This heat comes as dewpoints climb into the low 70s, which will
cause overall heat indicies in the afternoon to climb into the mid
to lower 100s.

It will not only be the impressive level of oppressive midday and
afternoon heat to contend with, but the cumulative impacts of only
having the mercury settle to near 70 for the overnights (Monday
night and beyond), thereby extremely limiting any relief.

While the added heat and humidity will also force a degree of
daytime instability next week and lead to some extent of diurnal
shower and storm development outside of the stable lake shadows.
There remains uncertainty in the position and orientation of the
upper ridge, as well as shortwave ripples expected to crest over it,
and the degree of the subsidence capping likely to be in place on
any given day. Thus PoP values remain low (15-20%) as confidence is
low in coverage and intensity of any potential convection that
develops or moves into the region next week.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
VFR conditions will be in place through this evening. The only
potential issue will be gusty sfc winds today. Winds of 15 to 25
knots will be fairly common through the afternoon...with some gusts
to 30 knots for the IAG Frontier (KIAG and KBUF).

A slow moving cold front will press through the region later tonight
and early Friday. While VFR flight rules are forecast to persist...
the front will support at least scattered shower and thunderstorm
activity.

Outlook...

Tonight and Friday...VFR/MVFR. Showers and thunderstorms likely.
Friday night through Monday...VFR.

&&

.MARINE...
A cold front will move across the lower Great Lakes late tonight and
early Friday. Southwest winds will increase ahead of the front
today, 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...RSH/TMA
NEAR TERM...TMA
SHORT TERM...PP
LONG TERM...PP/RSH
AVIATION...RSH
MARINE...AR/RSH/TMA