173
FXUS61 KBUF 271809
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
209 PM EDT Thu Jun 27 2024

.SYNOPSIS...
High pressure will drift from the western Great Lakes to the New
England coastline tonight and Friday providing us with dry and
comfortable weather. Low pressure tracking from the upper Great
Lakes to Quebec will bring a return to much more unsettled
weather Friday night and especially Saturday with periods of
showers and thunderstorms. High pressure and drier weather
return later Sunday and early next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
A compact shortwave dropping southeast out of southeast Ontario
may bring a spotty shower or two to the North Country late this
afternoon or early this evening, if the ongoing activity can
hold together.

Surface high pressure centered over the upper Midwest and western
Great Lakes will build into the region tonight, before drifting
east into New England on Friday. This will provide the region
fair dry weather through Friday.

Mainly clear skies and light winds will allow for ideal conditions
for radiational cooling tonight with overnight low temperatures
dropping into the mid to upper 40s across the interior Southern
Tier/North Country to the lower 50s elsewhere. Some patchy fog
is possible within the Southern Tier Valleys overnight.

On Friday, a developing southeasterly flow on the backside of
the departing high will help send temperatures into the mid 70s
across the North Country and the upper 70s to near 80 elsewhere.
Humidity levels will remain comfortable with surface dewpoints
in the mid 40s to lower 50s.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
A closed mid level low currently over the Pacific Northwest will
track across the continent the next couple days to eventually
support a storm system that will plague the Lower Great Lakes for
much of the upcoming weekend. Unfortunately...this may put a damper
on some outdoor activities...especially during the first half of
the weekend when showers and possible thunderstorms will be most
common.

After two beautiful days to end the work week...a shortwave and
accompanying sfc warm front will make their way out of Ohio into our
forecast area Friday night. While the bulk of the night will be rain
free...some showers are forecast to blossom mainly over the western
counties late. It will be distinctly warmer than the previous as
well with temperatures forecast to bottom out in the mid to upper
60s for most areas...except across the North Country where mins will
be within a degree or so of 60.

Saturday will then likely be the most unsettled of the two weekend
days. A warm front will complete its passage across our region by
late morning with most areas picking up some showers and possibly a
thunderstorm in the process. In the wake of the front...the region
will then be immersed within a sub tropical airmass with Td`s
surging into the lower 70s and PWAT values in the vcnty of 2 inches.
The soupy airmass will be prime for heavy showers and drenching
thunderstorms during the afternoon and early evening...as a pre
frontal trough will plow through the region. Will further raise cat
pops from continuity. Otherwise...it will be noticeably more humid
on Saturday with southerly winds gusting to between 25 and 30 mph.

The showers and thunderstorms will taper off for a few hours
Saturday evening...as the deep sub tropical plume of moisture will
be peeled away. During the course of the overnight though...we
should experience an uptick in shower activity immediate ahead of an
approaching cold front.

The cold front will push across our region early Sunday morning with
scattered nuisance showers marking the passage. Diurnally induced
instability will then promote fairly steep low level lapse rates
within the cold advective pattern...and with elongated shortwave
energy rounding the base of a digging longwave trough...additional
scattered showers will be possible for the afternoon. Regardless...
the vast majority of Sunday should be pcpn free. Otherwise...Sunday
will be breezy...cooler and less humid with highs mainly in the 70s.

While the base of a progressive longwave trough will pass over the
region Sunday night...a wealth of dry air abv a robust cap at H85
will nearly guarantee dry weather. The fly in the ointment though
will be a northerly flow of chilly air over a `warm` Lake Ontario.
Yes...there should be some lake induced clouds near and southeast of
Lake Ontario.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
High pressure building in from the west will provide drier, cooler,
and more comfortable conditions with surface dewpoints falling back
into the mid 40s and 50s across the region on Monday, lasting
through Tuesday. Daytime highs will be in the upper 60s to mid 70s
on Monday.

High pressure will slide east of the area on Tuesday with a
southerly return flow boosting highs back up into the mid 70s
to low 80s, however very tolerable humidity levels will remain in
place for one more day.

Shower and thunderstorm chances start to ramp up again toward mid
week as the next frontal system approaches the area with a warm
frontal segment crossing the area, followed by another cold front.
Exact timing of these features will become better resolved as we get
closer in time. Also, expect a return to very warm and humid
conditions.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
High pressure centered over the upper Midwest/western Great Lakes
will build into the region tonight. Diurnal cumulus field will erode
this evening with mainly patchy cirrus level cloud crossing the
region. Between 22z and 02z, a shortwave moving southeast out
of southeast Ontario could bring a few spotty showers to northern
New York including KART, however restrictions are not expected.
Some Southern Tier valley fog may bring some restrictions to
KJHW between 07z and 11z.

Outlook...

Friday...VFR.
Friday night...Mainly VFR with a chance of showers.
Saturday...Localized restrictions likely in increasingly widespread
showers and scattered thunderstorms...some of which may produce locally
heavy rainfall.
Sunday...A chance of a leftover shower or two...otherwise mainly VFR.
Monday and Tuesday...VFR.

&&

.MARINE...
Winds on the lower Great Lakes tonight will become light and
variable as high pressure from the western Great Lakes builds into
the region. Mainly easterly winds at 12 knots or less will
develop Friday as the high departs across New England, but some
local onshore breezes will likely develop during the afternoon.

Southeasterly winds early Friday night will veer to southerly as
a warm front lifts into the lower Great Lakes. These southerly
winds may increase to over 15 knots Saturday, but wave heights
in US waters likely remaining 3 feet or less.

A cold frontal passage will bring scattered thunderstorms Saturday
afternoon and Saturday evening with the potential for locally
gusty winds and higher waves. Behind the frontal passage,
westerly winds will strengthening to near 20 knots with a period
of advisory conditions possibly developing Sunday on both Lake
Erie and Lake Ontario.

&&

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

&&

$$

SYNOPSIS...JJR/TMA
NEAR TERM...TMA
SHORT TERM...RSH
LONG TERM...JM
AVIATION...TMA
MARINE...TMA