287
FXUS61 KBUF 021038
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
638 AM EDT Tue Jul 2 2024

.SYNOPSIS...
High pressure over New England will supply us with another nice day
as sunshine through high clouds will be accompanied by comfortable
temperatures and low humidity. A deepening southerly flow between
the exiting high pressure and an approaching cold front will then
allow mid summer heat and humidity to return on Wednesday. Showers
and thunderstorms...many with drenching downpours will then make
their way into our region later Wednesday and Wednesday evening.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
High pressure exiting across New England will guarantee us another
nice day. Unlike yesterday (Monday) though...cirrus blowoff from an
MCS over Wisconsin will shroud the sun with a fair amount of cirrus.
This will mainly be the case during the midday and afternoon with
the cirrus being the thickest near and east of Lake Ontario.

Otherwise...it will be a little warmer today...yet still quite
comfortable with continued low humidity. Weak warm advection will
allow our afternoon temperatures to return to within a couple
degrees of 80.

While fair dry weather will remain in place tonight...a warm front
will push through overnight. This will be marked by relatively thick
mid and high level cloud cover...once again focusing on areas near
and east of Lake Ontario. The frontal passage will guarantee a
noticeably warmer night. After two nights that were more typical of
early Fall...our mercury for most areas tonight will only drop into
the mid and upper 60s...an increase of roughly 15 degrees from
recent nights.

Wednesday is then GUARANTEED to be very warm and moderately humid...
as a deepening southerly flow ahead of an approaching cold front
will prompt Tds to return to the mid and upper 60s...while PWAT
values will surge to around 2 inches. This may sound like a broken
record from last week...as this increasingly sub tropical
environment will become ripe for afternoon convection. Forcing
the increasing chance for showers and thunderstorms...some with
drenching downpours and gusty winds...will be a pair of frontal
boundaries.

As is most often the case during the summer...the approaching cold
front will be preceded by a pre-frontal sfc trough. This will
help to initiate some thunderstorms over the Southern Tier and
western Finger Lakes during the afternoon...then more widespread
convection can be expected late in the day into the evening
with the passage of the actual cold front. Forecast bulk shear
of 40kts or so will increase the risk for organized convection
that could produce gusty winds...particularly over southern
areas. SPC highlights the most favored area for severe weather
to be well to our southwest...in the vcnty of the Ohio valley.

Temperatures on Wednesday will top out between 85 and 90...with the
higher end of that range expected for the lake plains where heat
index values will approach the mid 90s.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
A cold front will gradually drop across our region Wednesday night
and Thursday morning, with showers and thunderstorms through the
evening, then diminishing overnight as daytime instability
decreases. Greater instability does not arrive until the evening
hours maintaining thunderstorm chances and coverage area, of which
some could still be producing heavy downpours within a humid
atmosphere, and PWATs around 1.5 to 1.75 inches. The surface front
parallel to the convergent flow aloft could allow for training
cells, especially across WNY.

This front and deeper moisture drops to near the state line
Thursday. A few showers or thunderstorms near the state line,
otherwise much of the region will remain dry through the evening
hours. Winds Thursday night will be light, generally from the
northwest to west.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A mid level shortwave trough over the Midwest Friday and surface
low, will track across the Great Lakes and to southern Quebec
through Saturday night. A frontal boundary to our south will lift
back northward as a warm front, with showers and thunderstorms
forming within an increasing humid atmosphere ahead of the front.
Greatest coverage to convection will be Friday night and Saturday,
with the passing of the warm front, low level convergence on the
nose of a 35 to 40 knot LLJ that will reside under divergent flow
aloft, and broad scale lift ahead of the shortwave. Strongest storms
will likely be across eastern areas Saturday where lingering MUCAPE
values of 1000 J/KG and 0-6 km bulk shear values near 50 kts ahead
of a cold front could boost thunderstorms.

High pressure will settle across our region from the Ohio Valley
Sunday and Sunday night. From this direction, though humidity will
lower, it will not be that crisp autumn like feel to the air.
Falling heights, and southerly return flow Monday will give
potential for more showers and thunderstorms moving back into our
region.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
High pressure centered over eastern New York this morning will make
its way off the East coast this afternoon and evening. This will
support fair dry weather with wide open VFR conditions and light
winds through the TAF period.

Outlook...

Wednesday...VFR, then MVFR with showers and thunderstorms late
Wednesday afternoon and Wednesday night.
Thursday...Mainly VFR with a low chance of a shower or thunderstorm
across the western Southern Tier.
Friday and Saturday... Mainly VFR with a chance of showers and
thunderstorms.

&&

.MARINE...
High pressure exiting across New England will support light to
gentle winds featuring a primarily easterly component throughout the
Lower Great Lakes today...along with negligible waves. This will
favor good to excellent conditons for recreational boating through
the evening hours.

Winds will veer to the south and freshen somewhat later tonight and
Wednesday...as a cold front will approach the region. While fair
weather will remain in place through at least midday Wednesday...
there will be an increasing risk for thunderstorms Wednesday
afternoon and evening.

In the wake of the cold front...fair weather will return to the
region later Wednesday night with subsiding southwest breezes.

Looking ahead to the Fourth of July...gentle to moderate winds will
be in place throughout the region. These winds will be from the
southwest on Lake Erie and primarily from the west on Lake Ontario.

&&

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

&&

$$

SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...Thomas
LONG TERM...Thomas
AVIATION...RSH
MARINE...RSH