988
FXUS61 KBUF 190523
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
123 AM EDT Fri Jul 19 2024

.SYNOPSIS...
Sprawling high pressure centered near Chicago will gradually build
over our region through Saturday. This will provide us with
beautiful 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/...
Most areas will be able to enjoy moonlit skies tonight, but a
northwest flow of 10c H85 air over a 23/24C lake will be JUST
chilly enough to support some lake effect cloud cover between
ROC and SYR. Yes, tis the season when we are switching from
lake stabilized air to nocturnal instability at times over the
lakes. In any case, light winds and general clear skies
overnight will allow temps to drop through the 50s. In fact,
some of the normally cooler areas of the western Southern Tier
and in Lewis county could experience readings in the upper 40s.
These same areas could also see patchy valley fog.

High pressure will continue to build across the region Friday.
Daytime heating and low level moisture will result in cumulus cloud
development, however there should be less coverage than today,
Thursday. Highs will reach the mid to upper 70s across the region.
It will be another night of light winds and mostly clear skies, with
high clouds entering the forecast area into Saturday.

Troughing occurs across the Great Lakes Saturday. A southwest flow
in the mid-levels will bring increasing moisture and warm air across
the region. Dry conditions are expected with temperatures rising
back into the 80s across most of the region.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
Mid-level low pressure centered over the northern portions of the
providence of Quebec Saturday night will continue to deepen and
rotate eastward toward the Canadian Maritimes Sunday and Monday. At
the surface, high pressure overhead of the region will continue to
exit east toward the Atlantic coastline Saturday night, maintaining
dry weather.

A weak shortwave trough will traverse through the aforementioned
longwave pattern Sunday, supporting a backdoor cold front to slide
southeast across the forecast region Sunday afternoon. This front
continues to look moisture starved, 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.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
The longwave pattern across the CONUS will gradually shift moving
further into the new workweek. This will come as a deep closed low
slinks out of the Gulf of Alaska and towards the Pacific Northwest,
causing a deeper amplification of the ridging over the Desert
Southwest while downstream troughing remains over the Mississippi
Valley. Reinforcing shortwave energy will concurrently propagate
southeast out of central Canada and into the Great Lakes region,
resulting in a broad, positively tilted trough replacing the zonal
flow over much of the eastern half of the the Lower 48. This trough
will allow a gradual northward advection of GOMEX based moisture
into the Northeast.

In terms of how this will impact the sensible weather across the
eastern 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 /06Z FRIDAY THROUGH TUESDAY/...
Surface high pressure will build across the region overnight through
Saturday. Light winds and mostly clear skies will result in VFR
conditions through Saturday morning. Patchy fog is possible, mainly
across valley locations and may approach KJHW and KOLE overnight.
Confidence is low that it will reach the airports at this time.

Outlook...

Friday through Monday...VFR.
Tuesday...Showers and thunderstorms possible. Mainly VFR/MVFR.

&&

.MARINE...
High pressure over the Upper Mississippi valley will slowly settle
across all of the Great Lakes region through the weekend. This
resulting weak sfc pressure will then only support gentle to
occasionally moderate breezes and negligible waves THROUGH the
weekend.

&&

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

&&

$$

SYNOPSIS...RSH/TMA
NEAR TERM...HSK/RSH/TMA
SHORT TERM...EAJ
LONG TERM...PP
AVIATION...HSK/RSH
MARINE...RSH