622
FXUS61 KBUF 141800
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
200 PM EDT Fri Jun 14 2024

.SYNOPSIS...
A weak cold front could touch off a shower or two across the North
Country late this afternoon and evening...otherwise high pressure
moving in from the Upper Great Lakes will supply us with fantastic
weather for the weekend. Oppressive heat and humidity will then
DOMINATE our weather next week with dangerously high apparent
temperatures...peaking in the upper 90s to low 100s Tuesday and
Wednesday.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
Delightful weather with wall to wall sunshine will be in place for
the remainder of the afternoon...although a weak cold front sagging
south from the Ottawa valley could support a passing shower or two
across the North country.

Tonight...expansive high pressure centered over the Upper Great
Lakes will slowly drift to the southeast towards our region. While
some clouds wil be found across the North country to start...this
scenario will promote moonlit skies tonight with temperatures
dipping to below normal levels. Mins will range from the mid 50s in
most areas to the mid and upper 40s across much of the Srn Tier and
also across Lewis county.

The large area of high pressure will move directly over our region
Saturday and Saturday night. This will support mainly clear skies...
although it will be on the cool side of normal with Saturday
afternoon temperatures only in the 60s to near 70. Mins Sat night
will be similar to those of tonight...if not a degree or two lower.

Enjoy this pleasant weather now...as dangerously oppressive heat and
humidity is guaranteed for much of next week.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Superb weather for the weekend as an expansive ridge will build
over the Great Lakes. This will keep the area dry, and outside
of a few passing mid/high clouds Sunday, under mostly clear skies.

As the surface ridge crests east of the region Sunday and moves
off the East Coast by Sunday night, temps will get a boost into
the mid/upper 70s, likely a few readings in the 80s across far
western NY.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
...Dangerous Heat Wave To Impact The Region Next Week...

A very strong 500mb ridge will anchor itself across much of the
eastern CONUS and western Atlantic through much of the week, which
will dominate the sensible weather across the eastern Great Lakes.
NAEFS ensemble guidance continues to indicate this ridge will be of
anomalous strength with 500mb heights in the 99th percentile, if not
exceeding the maximum climatological values for the Northeast for
nearly the whole week. Latest runs of the deterministic ECMWF in
particular continue to forecast overhead 500mb heights reaching
600dam, with coincident 850H temps near +24C at times. Deep
anticyclonic flow around the resultant Bermuda High will cause hot,
humid air to surge across the eastern CONUS. Given the strong signal
from nearly all available long range guidance packages, confidence
is high in a prolonged stretch of oppressive summer heat and
humidity lasting through much of the week.

Forecast thinking has not changed much from previous updates in
regards to expected temps and heat indices next week. Daytime highs
Monday will feature widespread upper 80s and lower 90s, remaining a
bit cooler across the North Country in the upper 70s to mid 80s as
slightly cooler airmass initially lingers in the region. By Tuesday
and Wednesday, widespread high temperatures in the low to mid 90s
are expected. Highest temps will be in the interior valleys, while
cooler temps will be found 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 90s to lower 100s. Temps are expected to be a
few degrees lower on Thursday, back down into the upper 80s and low
90s. For context, daytime highs average the upper 70s for Buffalo,
Rochester, and Watertown during the days of June 17-21.

Even though heat indices will peak in the afternoon hours each day
next week, nighttime will offer very little (if any) relief. Low
temperatures from Monday night onwards are expected to only be in
the low to mid 70s, with high humidity likely making for VERY muggy
sleeping weather.

Otherwise...The primary forecast uncertainty through much of next
week continues to be on convective potential. Guidance continues to
indicate a series of "ridge rider" showers and storms periodically
cresting over the ridge and into the eastern Great Lakes region, the
first batch of which could potentially arrive as early as Monday
night. In addition, with dewpoints climbing into the upper 60s and
low 70s, daytime surface based instability will likely be present
each afternoon...Though the strong ridge should preclude much of the
diurnal convective potential with strong capping expected to be in
place. Given the low confidence in shower and storm timing and
coverage, PoPs values remain on the low side (15-30%) through
Thursday.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
While a weak secondary cold front could touch off a shower across
the North country late this afternoon and evening...fair VFR weather
with light winds can be expected through the TAF period.

Outlook...

Sunday and Monday...VFR.
Tuesday through Wednesday...VFR, but a slight chance for afternoon
thunderstorms inland from the lakes.

&&

.MARINE...
Westerly winds behind a front should remain below 15 knots today,
before becoming more northerly and weakening tonight. High
pressure will 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
NEAR TERM...RSH
SHORT TERM...PP
LONG TERM...PP
AVIATION...RSH
MARINE...AR/RSH/TMA