812
FXUS61 KBUF 270634
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
234 AM EDT Thu Jun 27 2024

.SYNOPSIS...
A secondary cold front will cross the region this morning along with
a few more widely scattered showers...with the best chances for
these found across the North Country. Otherwise high pressure will
drift from the western Great Lakes to the New England coastline
through Friday while providing us with dry and comfortable weather.
Low pressure tracking from the Upper Great Lakes to Quebec will then
bring a return to much more unsettled weather for Friday night and
especially Saturday...before high pressure and drier weather return
for later Sunday and early next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 0630z regional surface analysis shows a secondary cold front
draped from the Golden Horseshoe region of Southern Ontario to the
Saint Lawrence Valley...with some scattered showers noted across the
latter. Through the rest of the night this boundary will slip a bit
further south into western and North Central New York...and in the
process will bring a few more scattered showers to the North
Country...with an isolated light shower or sprinkle possible further
south and west. Otherwise conditions will be dry...with residual
moisture and developing upslope flow behind the secondary front
allowing for areas of lower stratus to continue to develop. Some fog
will also be possible within the Southern Tier River Valleys...
though the aforementioned cloud cover may help to keep this limited
in scope. Low temps will range from the mid 50s to lower 60s.

The secondary cold front will then finish sliding across our area
Thursday morning...with its weak nature and accompanying shallow
moisture field likely precluding this feature from generating much
more than a few additional widely scattered showers...with the best
chances for these again found across the North Country. Following
its passage...Canadian high pressure and cooler/drier air will build
across our region bringing largely dry and uneventful weather...with
early morning low clouds giving way to increasing amounts of
sunshine. Still can`t completely rule out another isolated pop-up
shower across the North Country Thursday afternoon as another
shortwave dives across Southern Ontario and Saint Lawrence
Valley...however probabilities for this appear lower than what was
previously seen the past couple of nights. The incoming cooler
airmass will also provide us with pleasant temperatures and humidity
levels...with highs mostly ranging from the upper 60s across the
higher terrain to the lower 70s elsewhere...and surface dewpoints
falling through the 50s through the course of the day.

The expansive surface high will then build directly overhead
Thursday night...before drifting east into New England on Friday.
This will provide us with continued fair dry weather to close out
the work week. Excellent conditions for radiational cooling will
allow Thursday night`s lows to settle into the mid-upper 40s across
the interior Southern Tier/North Country and to the lower 50s
elsewhere...with a little more patchy fog possible within the
Southern Tier Valleys overnight. On Friday...a developing
southeasterly return flow on the backside of the departing ridge
will then allow highs to recover to the mid 70s across the North
Country and the upper 70s elsewhere...while humidity levels will
still be quite comfortable with surface dewpoints remaining confined
to the upper 40s to mid 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 WEDNESDAY/...
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 /07Z THURSDAY THROUGH MONDAY/...
A secondary cold front will drop south across the area overnight and
early Thursday morning while producing a few more widely scattered
showers across the North Country...with an isolated light shower or
sprinkle possible elsewhere. Otherwise residual low level moisture
and increasing upslope flow behind the front will lead to areas of
MVFR to IFR stratus...with the lowest ceilings most likely across
the higher terrain. Across the Southern Tier some patchy valley fog
may also develop...though this may be remain limited in scope due to
the aforementioned lower cloud cover.

Behind the secondary front Canadian high pressure and drier air will
build into the region on Thursday...while helping to lift and mix
out any lower stratus and fog. This will result in a return to
widespread VFR conditions by late morning or midday.

The surface high will then settle directly overhead Thursday night.
This will result in tranquil VFR conditions for the most part...with
the lone possible exception to this being some Southern Tier valley
fog and attendant restrictions overnight.

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...VFR.

&&

.MARINE...
A secondary cold front will cross the Lower Great Lakes overnight
and early Thursday morning...with modest westerlies out ahead of the
front veering to northwesterly and increasing a little in its wake.
A general northwesterly flow will then back a bit to westerly again
during the course of Thursday...with winds across the eastern half
of Lake Ontario turning moderately brisk for a brief period in the
afternoon. This said...winds and waves are expected to remain below
SCA criteria.

Thursday night winds will lighten again and veer to easterly as the
axis of surface high pressure crosses the area...before freshening a
bit again out of the east on Friday as the high departs across New
England. Again though...winds and waves are expected to remain below
advisory criteria.

&&

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

&&

$$

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