232
FXUS61 KBUF 192045
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
445 PM EDT Fri Jul 19 2024

.SYNOPSIS...
Sprawling high pressure will remain across the Great Lakes through
Saturday. This will provide fair weather and comfortable conditions
through at least the first half of the weekend, then a weak moisture
starved cold front will fall apart over our region on Sunday. Our
next chance for widespread shower activity will come Tuesday and
Wednesday of next week when mid summer humidity will return.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
High pressure will remain across the area through most of Saturday,
then a moisture starved cold front will approach from the north late
Saturday night. Visible satellite imagery shows diurnal cumulus
continuing late this afternoon inland of lake influences, with nice
lake shadows setup around the periphery of the eastern Great Lakes.
These diurnal cumulus will dissipate through the evening hours with
the loss of daytime heating, leaving clear skies and light winds.
Good radiational cooling conditions, with some patchy Southern Tier
valley fog developing again later tonight. Lows will range through
the 50s.

Slightly warmer air aloft on Saturday, which should reduce the
amount of diurnal cloud cover for most areas. The exception is
across the upper Genesee River Valley where there will be a bit more
moisture and cloud cover. Near normal highs in the upper 70s to
lower 80s.

A weak frontal boundary may spark an isolated shower across the St.
Lawrence Valley late Saturday night, otherwise it will be rain-free.
Lows will range from the mid 50s to low 60s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A weak shortwave trough will traverse through the midlevel longwave
over northern Quebec Sunday, supporting a backdoor cold front to
slide southeast across the forecast region Sunday afternoon. Along
this front, clouds will gather within a ribbon of deeper 850-700 hPa
moisture, however despite this a few spotty showers can`t be ruled
out, especially across the Niagara Frontier.

This front will then stall across New York State Monday. While the
area will remain mostly dry, a few afternoon showers will be
possible with the frontal boundary overhead. The better activity
Monday lies across the southeastern portions of the area from
Allegany County to the Finger Lakes.

Temperatures will be near to slightly above normal with the base of
a longwave trough over our region.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A weak broad, positively tilted trough will drop south from central
Canada into the Great Lakes region this week. This trough will allow
a gradual northward advection of GOMEX based moisture into the
Northeast.

Translating this pattern for the weather across the lower Great
Lakes, the increasingly unstable environment will allow for a return
to a much more unsettled pattern with chances for showers and
thunderstorms Tuesday through Thursday. In general, chances will be
highest across the interior in the afternoon hours each day when
diurnal heating is at its strongest, while diminishing overnight and
into the morning hours. PWATs near or exceeding 1.7" within this
increasingly humid airmass will allow for periods of heavy rain,
though there remains typical long range model discrepancies on how
exactly the trough across the East will evolve which limits
certainty in timing, placement and amounts.

Temperatures Tuesday will top out in the low to mid 80s in most
spots, while reaching the upper 70s and low 80s Wednesday and
Thursday though with increased humidity. Overnight lows with range
in the 60s each night.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
Surface high pressure will remain across the region through
Saturday, resulting in predominantly VFR flight conditions. Diurnal
cumulus late this afternoon will have VFR bases around 5-7kft. These
will dissipate through the evening hours. Patchy valley fog will
develop again in the Southern Tier tonight and may cause
localized IFR conditions, however it did not make it into KJHW
last night, thus will continue to keep it out of the terminal
later tonight at this point. VFR flight conditions on Saturday
with weak lake breeze circulations developing in the afternoon.

Outlook...

Saturday night through Monday...VFR.

Tuesday and Wednesday...Mainly VFR/MVFR. Showers and thunderstorms
possible.

&&

.MARINE...
High pressure will remain across the Great Lakes through Saturday. A
weak cold front will wash out as it drops southward across the
eastern Great Lakes early Sunday. This will result in a weak
pressure gradient only supporting gentle to occasionally moderate
breezes and negligible waves through the weekend.

&&

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

&&

$$

SYNOPSIS...Apffel/RSH/TMA
NEAR TERM...Apffel/JM
SHORT TERM...EAJ/Thomas
LONG TERM...EAJ/PP
AVIATION...Apffel/JM
MARINE...Apffel