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864
FXUS61 KBUF 200536
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
136 AM EDT Fri Sep 20 2024

.SYNOPSIS...
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High pressure will remain centered over Quebec through tonight, with
a ridge extending back towards the eastern Great Lakes providing
another day of dry and warm weather. A mid level disturbance will
then cross the area Saturday through early Sunday morning, bringing
showers and a few thunderstorms with uneven coverage of rain. A
narrow ridge of high pressure will bring a brief return to dry
weather for much of Sunday and Sunday night. A slow moving area of
low pressure will then bring several days of rain showers starting
Monday and lasting much of next week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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IR satellite imagery and surface observations showing clear skies
across the region early this morning, with areas of fog developing
from the Southern Tier river valleys east across the Finger Lakes to
areas east/southeast of Lake Ontario. The fog will continue through
mid morning before burning off.

Surface high pressure centered over eastern Quebec will remain in
place today, with a weaker ridge surface and aloft extending back
across the eastern Great Lakes. This will provide another dry and
warm day with mostly sunny skies outside of some modest increase in
high clouds from west to east, and a few diurnal cumulus along and
inland of the lake breeze boundaries. Highs will be similar to
yesterday, with lower 80s for the lower elevations and mid to upper
70s for higher terrain and the immediate lakeshores.

Tonight, weak surface high pressure will remain in place across the
eastern Great Lakes. A mid level trough over the upper Great Lakes
will advance ESE overnight, with height falls and DPVA starting to
spread into southern Ontario just upstream of Western NY. This will
bring an increasing and lowering mid level cloud deck overnight, but
showers should remain west of the area until around or just after
daybreak Saturday. The increase in clouds and an uptick in southerly
flow should keep fog formation to a minimum.
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&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Heading into Saturday, a broad mid-level trough will lie across much
of the western two-thirds of the CONUS, while a ridge continues to
lie across the Northeast. With the aforementioned trough, a
shortwave trough will be in the midst pivoting northeast across the
western and central Great Lakes. With this the surface ridge in
place across the Northeast throughout much of the week will weaken
some Saturday and allow for some precipitation and afternoon
thunderstorms to drop southeast across western New York. While it
doesn`t look like a complete wash out, expect a few hundredths
across the Niagara Frontier with the best location for rain across
the southern Tier with a little over a tenth of an inch possible.

Surface high pressure over the Canadian Maritimes will then drop
southeast across the Northeast into the Lower Great Lakes Sunday,
supporting one more day of dry weather.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The pattern becomes more amplified next week with the eastern Great
Lakes region under southwest flow between a trough centered across
the Upper Mid-West and a ridge over New England. Unsettled weather
is possible as moisture increases across the forecast area.

The upper level ridge axis will shift eastward while a shortwave
trough moves across the Upper Mid-West region Monday. There is low
confidence in the place of low pressure ahead of the trough, however
a southwest flow will likely increase moisture across the region
Monday into Monday night. Shower chances increase from west to east
by late Monday across western NY and across the entire region Monday
night. Details become fuzzy Tuesday and on as certainty lowers with
the evolution of another shortwave trough and the duration of a dry
slot between systems. Looking at the ensemble means of the large
scale pattern, the main trough should stay to the west of the
forecast area, opening the door to increasing moisture and other
organized systems moving from the Ohio Valley into the eastern Great
Lakes region. Low to medium chances for showers continue Tuesday
through Thursday. A few thunderstorms are possible if favorable
conditions come together.

Temperatures remain slightly above normal next week with highs
averaging in the low 70s across the lake plains to the upper 60s
across the higher terrain.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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Clear skies and light winds will promote an expansion of fog through
the early morning hours, with areas of MVFR/IFR. The fog will be
most prevalent from the river valleys of the Southern Tier through
the Finger Lakes to points southeast of Lake Ontario. KJHW, KART,
and KROC all may see a few hours of IFR in fog around daybreak,
although confidence is not particularly high for any of those
airfields.

The fog will burn off by 14Z, leaving VFR to prevail for the rest of
the day with just a modest increase in high clouds from west to
east, and a few diurnal cumulus along and inland of the lake breeze
boundaries. Dry weather and VFR will continue to prevail tonight
with mid level clouds increasing and lowering from west to east. The
increase in clouds and increasing southerly winds should keep fog
formation to a minimum.

Outlook...

Saturday...VFR/MVFR with showers likely and a chance of
thunderstorms, especially across Western NY.
Sunday...VFR, except for patchy early morning fog with local IFR
across the Southern Tier and east of Lake Ontario.
Monday and Tuesday...VFR/MVFR with showers likely and a chance
of thunderstorms.
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&&

.MARINE...
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High pressure will remain over eastern Quebec and the Canadian
Maritimes through the weekend. The pressure gradient to the west of
this high will start to increase east to northeast winds on Lake
Ontario today with a light chop, and moreso over the weekend with a
moderate chop developing. Winds will generally be lighter on Lake
Erie through the weekend.
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&&

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

&&

$$

SYNOPSIS...Hitchcock
NEAR TERM...Hitchcock
SHORT TERM...EAJ
LONG TERM...HSK
AVIATION...Hitchcock
MARINE...Hitchcock