046
FXUS61 KBUF 180715
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
315 AM EDT Thu Jul 18 2024

.SYNOPSIS...
Behind a cold front, a much drier airmass will settle upon our
region today and through much of the weekend. A stray shower this
afternoon east of the Lakes as a secondary surface trough passes
through the region, but no widespread rain showers until the middle
of next week when summer`s humidity returns.

&&

.NEAR TERM /THROUGH TONIGHT/...
A drier airmass begins to build across our region this morning
behind a cold front that is exiting our eastern zones. Water Vapor
imagery displays a well defined mid level trough over the central
Great Lakes, advancing towards the eastern Great Lakes. The axis of
this mid level trough will cross our region today.

At the surface this morning fog is filling the valleys of the inland
Southern Tier. Temperatures this morning are about 10 degrees
cooler than 24-hours ago.

While the drier airmass over our region will limit precipitation
there is still a small chance for a few stray showers east of the
Lakes. With lift along a secondary surface trough, and steepening
mid level lapse rates with the passage of the mid level trough axis,
strato-cumulus clouds will expand across portions of the region,
with perhaps enough lift for a stray shower east of both Lakes.
Variable cloudiness will remain through the afternoon before early
evening cooling, the continued advection of drier air and subsidence
behind the mid level trough clear skies tonight.

With light winds on the leading edge of an area of high pressure to
the west, we will have good radiational cooling tonight with lows
ranging through the 50s with comfortable levels of humidity. Some
valley fog is again possible in the valleys of the Southern Tier.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure at the surface and troughing aloft will be across the
region Friday. This will lead to an outstanding day with high
temperatures in the mid to upper 70s, low humidity and plentiful
sunshine. Mainly clear skies and light winds will lead to ideal
radiational cooling conditions Friday night, allowing temperatures
to fall into the 50s along with some patchy Southern Tier valley
fog.

A transition to zonal flow aloft with surface high pressure sliding
to the east should maintain fair weather Saturday and Saturday
night, although there is some hint of a few light showers possibly
sneaking into the Saint Lawrence Valley and northern New York
Saturday evening. Despite this, soundings indicate dry air in low
levels therefore will continue to leave the forecast dry areawide.
Flow becomes more southerly behind the departing high with warmer
temperatures expected Saturday with highs building back into the
80s.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Mid-level low pressure centered over Quebec, Canada will amplify
Sunday as a shortwave trough rounds its base. At the surface, high
pressure spread across the area Saturday will remain mostly in place
Sunday, however a backdoor cold front will slide southeast across
New York state. This front looks to be moisture starved, and
therefore a low chance for a few spotty showers. In the wake of this
front, surface high pressure will re-establish itself across the
lower Great Lakes for the start of the week, continuing dry weather
Monday and Monday night.

Uncertainty remains for Tuesday and Wednesday with a broad, weak
trough over the Plains moving slowly east into the Mississippi
Valley. This will support a diffuse area of moisture and general low
pressure drifting northeast across the Ohio Valley. Depending on the
northward extent of the moisture Tuesday, chances for showers will
be possible, and remain likely south of the forecast area. As the
moisture further creeps northward Wednesday, the chances for showers
will continue.

Otherwise, temperatures will warm this weekend with highs slightly
above average for the end of the weekend and the start of next week.
Highs will range in the low to mid 80s.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
For the 06Z TAFS VFR flight conditions are found across the region
as drier air builds over TAF sites behind an east bound cold front.
Fog is filling the river valleys of the inland Southern Tier this
early morning, and this fog may expand westward towards KJHW as
there is still low dewpoint depression.

Otherwise dry weather is expected across the TAF region today and
tonight. A secondary surface trough may develop a low VFR deck of
clouds east of the Lakes later this morning and through the
afternoon. Light northwest to north winds today will become light
and variable tonight as surface high pressure to the west expands
across the region. Again some valley fog is possible in the Southern
Tier.

Outlook...

Friday through Monday...VFR.

&&

.MARINE...
High pressure over the Upper Mississippi valley this early morning
will slowly settle across all of the Great Lakes region today and
through the weekend. There is a light northwest to north flow over
the Lakes this morning, with waves a foot or so on the southern and
southeastern shores of the lower Great Lakes.

This flow will become light and variable tonight, with waves under a
foot on the Lakes. The weak surface pressure gradient with the
surface high will bring gentle to moderate breezes and negligible
wave action through the weekend.

&&

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

&&

$$

SYNOPSIS...Thomas
NEAR TERM...Thomas
SHORT TERM...TMA
LONG TERM...EAJ
AVIATION...Thomas
MARINE...Thomas