446
FXUS61 KBUF 141329
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
929 AM EDT Fri Jun 14 2024

.SYNOPSIS...
The first of two cold fronts will move through the region this
morning while producing a couple showers east of Rochester. A second
reinforcing cold front will move through late this afternoon and
evening with a shower ore two across the North country. The weekend
weather should be fantastic with fair dry weather comfortable
conditions. 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/...
A somewhat moisture starved cold front will complete its passage
across our forecast area during the late morning and midday hours.
While the majority of the region will experience partly to mostly
skies in the process...there will still be a couple showers
around...mainly east of Rochester. Otherwise...it should be
delightful this afternoon with low humidity and temperatures that
will mainly be in the 70s.

A second...reinforcing cold front will slip across the North country
late this afternoon and evening. This could result in a couple more
showers for that area...otherwise expansive high pressure
approaching from the Upper Great Lakes will provide us with moonlit
skies and cool overnight lows in the upper 40s to mid 50s.

The large area of high pressure will move directly over our region
on Saturday. This will support sun filled skies...although it will
be on the cool side of normal with afternoon temperatures only in
the 60s to near 70. Enjoy this pleasant weather now...as dangerously
oppressive heat and humidity is guaranteed for much of next week.

&&

.SHORT TERM /SATURDAY NIGHT 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. Lows Saturday night will be rather chilly with a
range of 40s across the interior and low 50s closer to the
lakes. Warmer for Sunday night with a range of 60s across the
region, possibly near 70 close to the Lake Erie shoreline.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
...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 /14Z FRIDAY THROUGH TUESDAY/...
While a cold front moving through the region could still allow for a
shower east of Rochester through midday...VFR weather will be in
place. The only exception will be across the Eastern Lake Ontario
region where some MVFR cigs will be possible through midday.

VFR weather with light winds will then be firmly ensconced across
the region tonight through Saturday.

Outlook...

Sunday through Tuesday...VFR.

&&

.MARINE...
A cold front will move across the lower Great Lakes this
morning. Westerly winds behind the 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