035
FXUS61 KBUF 141406
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1006 AM EDT Wed Aug 14 2024

.SYNOPSIS...
High pressure centered over the Great Lakes will build east and
support mainly dry weather through Thursday night, although there
could be a few hit and miss showers east of Lake Ontario. Notably
higher chances for showers and thunderstorms will arrive Friday and
into the weekend. Temperatures will become gradually warmer as the
week goes on.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure will remain across the Great Lakes today...
guaranteeing plenty of sunshine. 850 mb temperatures forecast to be
around +14C will result in afternoon temperatures peaking in the
upper 70s to lower 80s, perhaps a few mid 80s. Subtle trough working
through New England and eastern New York could bring the outside
chance a shower to the eastern Lake Ontario region this afternoon.

Mainly clear skies tonight will result in favorable radiational
cooling with valley fog forming overnight. Low temperatures in the
lower 60s along the lake plains to the mid 50s for interior sections.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Ridging remains in control for areas south of Lake Ontario, while a
trough of low pressure lingers across eastern NY and New England on
Thursday resulting in a mainly dry day. Although a stray shower is
possible for areas along and inland of any lake breeze boundaries
across western NY during the second half of day, chances for a
widely scattered shower or storm will be a bit better across inland
areas east of Lake Ontario during the afternoon closer to a weak
surface trough lingering across northern NY and cool cyclonic flow
aloft associated with the western fringe of the upper level trough
across New England. Dry weather is expected Thursday night as a
transient upper level ridge crosses the region, while surface high
pressure moves east across New England.

Temperatures will increase a bit more with highs Thursday ranging
from the upper 70s to mid 80s. A light southeasterly return flow
will develop Thursday night as the surface high slides east into New
England. This will result in warmer overnight lows with the bulk of
the area bottoming out in the low to mid 60s, with some upper 50s
found across the inland higher terrain.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
An amplifying upper level ridge across the Rockies and central CONUS
will help promote a large scale downstream upper level trough to dig
across the eastern Great Lakes and New England that is expected to
persist through most, if not all of the long term period. This will
result in unsettled weather for our area with bouts of showers and
storms expected.

Transient upper level ridge will move east over New England, while
surface high pressure slides off the New England coast Friday. In
its wake, a longwave trough will then slowly encroach on the
forecast area from the west while digging southward from
southeastern Canada into a good portion of the eastern third of the
CONUS. A sharpening, cyclonically curved jet rounding the base of
this trough will allow for a steady transport of deeper GOMEX
moisture into the eastern Great Lakes region with increased humidity
and PWATs quickly rising to between 1.5-1.8" from west to east
Friday. Combined with the increased synoptic forcing and large scale
height falls aloft, expect chances for showers and thunderstorms to
increase in tandem Friday, with precipitation chances making it as
far east as the Genesee Valley by late in the day. The greatest
potential will be across far western NY closer to the approaching
warm front. Deeper moisture and better forcing then move into our
area Friday night bringing the likelihood for a period of showers
and storms, some of which could be heavy at times.

Very unsettled weather persists across the entire forecast area
through the weekend and possibly into Monday as the stacked trough
of low pressure partially closes off north of the region, while at
the same time Ernesto churns northward through the western Atlantic
along the eastern periphery of the trough. The combination of these
factors will cause a slowing eastward progression of the system.
Expect the greatest chances for showers and thunderstorms Saturday
through Monday to be during peak diurnal heating hours in the
afternoon each day, though this activity could persist through the
overnight periods with the main trough axis remaining upstream until
sometime later Monday. There will be some dry time built in as well,
but timing is very difficult to pin down this far out as is
typically the case. Given the high PWATs in place, some of this
convection could result in the continued threat for localized heavy
rainfall during this period.

Once the trough axis and associated surface cold front finally shift
east of the area, surface high pressure will begin to slowly build
back into the region from the west Monday night into Tuesday. There
could be enough wraparound moisture present to spur the development
of a few additional showers, though we should see much more in the
way of dry weather.

Temperatures will be above average for the finish of the work week
into the start of the weekend, before slowly falling to near or even
a little below average by the tail end of the period as
progressively cooler air associated with the trough settles across
the region.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
Widespread VFR conditions will be in place today...as high pressure
centered over the Great Lakes will drift east. There is an outside
chance of an afternoon shower, but unlikely that any TAF sites will
be impacted.

Mainly clear tonight with valley fog developing across the Southern
Tier with vsby restrictions likely from KJHW to KELZ.

Outlook...

Thursday...VFR.
Friday...Mainly VFR. Chance for showers late.
Saturday and Sunday...MVFR to IFR with showers and thunderstorms likely.

&&

.MARINE...
High pressure across the eastern Great Lakes will maintain quiet
conditions on Lake Erie and Lake Ontario through Thursday. The light
flow will favor the development of afternoon lake breezes through
Thursday. A southeasterly flow will develop by Thursday night and
Friday as a warm front approaches the region, but speeds should
remain less than 15 knots. A general south-southwest flow develops
behind the warm frontal passage for the weekend period as low
pressure meanders north of the lower Great Lakes.

Speeds could exceed 15 knots both Saturday and Sunday afternoons,
so cannot completely rule out the potential for marine headlines
this weekend. The risk for thunderstorms increases on the lower
Great Lakes Friday through Sunday.

&&

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

&&

$$

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