898
FXUS61 KBUF 262300
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
700 PM EDT Wed Jun 26 2024

.SYNOPSIS...
Showers and thunderstorms will end from west to east this
evening. Cooler and less humid conditions expected Thursday and
Friday. Active weather returns Saturday as a cold front crosses
the region. Dry weather return Sunday as high pressure builds
in for the start of the new work week.

&&

.NEAR TERM /THROUGH THURSDAY/...
A frontal boundary near the NY/PA state line has divided more
unstable air to its south from a relatively stable environment
to its north. 7 p.m. LAPS CAPE depicts this well with virtually
no SB CAPE in Western NY north of the boundary. As a result,
a large slug of showers with embedded thunderstorms due to
elevated instability is moving across Western NY early this
evening. This slug will exit from west to east during this
evening. After this,a cold front will move through, and this
will generally bring scattered showers and possibly a
thunderstorm to Western NY overnight. Northerly flow and
residual low-level moisture behind the front should allow for
some lower stratus to develop overnight. Some fog is possible
for area which sees rainfall through this evening.

A secondary cold front will finish crossing the area Thursday
morning, bringing a few additional showers. A weak shortwave will
dive across southern Ontario and the Saint Lawrence valley Thursday
afternoon behind the passage of the front bringing the potential
for a few instability showers across the North Country. Otherwise
generally dry weather is expected Thursday, with early morning
low clouds giving way to increasing amounts of sunshine as high
pressure and cooler/drier air builds in. The incoming airmass
will also lead to cooler temperatures and lower humidity levels.
High temperatures ranging from the upper 60s across the higher
terrain to the lower 70s elsewhere with surface dewpoints
falling through the 50s.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
Surface high pressure will crest across our region Thursday night
through Friday evening, providing comfortable levels of humidity and
fair weather. Patchy fog is possible across SW NYS.

Behind the surface high deep southerly flow will transport moisture
northward, with Pwat values peaking near 2 inches by Saturday
afternoon.

Showers, first within isentropic lift along a warm front extending
across our region Friday night and Saturday morning will become more
numerous Saturday afternoon and evening within the deepening
moisture and passage of a subtle shortwave. The evening timing of
the pre-frontal trough, cloud cover holding instability back to
around 750 J/KG or less and poor mid level lapse rates under 6 C/KM
are not favorable for strong to severe storms. However, 0-6 km bulk
wind shear values 35 to 45 kts could aid in strength to the storm if
any taller storms can develop. In addition the very moist atmosphere
will allow for localized heavy rainfall to develop. Training cells
within a SW flow could bring localized ponding of water through
Saturday mid- overnight. Actual cold front will remain off to our
west through the night, leaving a still humid, warm atmosphere with
prospects for fog in place.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
On Sunday the surface low will slide across east-central Quebec to
the Gulf of Saint Lawrence with a mid level shortwave and its
associated initial cold front crossing our area during the morning.
This will be followed by the passage of the main mid-level trough
axis and an associated weaker secondary boundary later Sunday/Sunday
night. Of note with the second cold front will be the much cooler
airmass that gets ushered in behind it with 850Ts dropping back into
the mid single digits C. The passage of these features will support
the potential for some additional scattered showers into at least a
portion of Sunday night (especially eastern areas), and (during
Sunday) a couple more isolated storms. Otherwise 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, lasting through Tuesday. Daytime
highs will be in the mid to upper 70s Sunday and the upper 60s to
mid 70s on Monday. High pressure slides 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. Comfortable overnight lows ranging through
the 50s Sunday night and Monday night.

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 /00Z THURSDAY THROUGH MONDAY/...
Steady showers will end from west to east this evening, with
some thunderstorms embedded in this large area of rain showers.
Mainly VFR outside of areas of MVFR or lower vsby in locally
heavy rains. After this, a cold front will move across the area
overnight, with increasing low level moisture and a risk for
MVFR or lower cigs. Across higher terrain in the Southern Tier,
there may be IFR cigs. Fog may also develop there, especially if
clouds scatter out at all.

Any fog or stratus will lift and scatter during the day
Thursday, giving way to widespread VFR flight conditions by
mid-day.

Outlook...

Thursday night and Friday...Mainly VFR.
Saturday...Localized restrictions with shower likely and a chance of
thunderstorms.
Sunday and Monday...Mainly VFR.

&&

.MARINE...
A period of light, variable winds across the lakes will precede
increasing northwesterly winds behind a cold front tonight,
though winds and waves are expected to remain below SCA
criteria.

&&

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

&&

$$

SYNOPSIS...AR/TMA
NEAR TERM...Apffel/TMA
SHORT TERM...Thomas
LONG TERM...JM
AVIATION...AR/Apffel/TMA
MARINE...AR/Apffel/TMA