500
FXUS61 KBUF 260649
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
249 AM EDT Wed Jun 26 2024

.SYNOPSIS...
Warm and mild again today with a better chance of showers and some
thunderstorms, especially in the Southern Tier in the afternoon.
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 into the for the
beginning of next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Regional radar show a broken line of showers and embedded thunder
with the cold front dropping southeast out of Ontario Canada.
This front is expected to enter the CWA between 07Z-09Z with
some limited chances for shower or an isolated rumble of
thunder. As was mentioned...the best shot for shower activity
will be found east of Lake Ontario.

Otherwise...modest southwest wind flow will keep temperatures up
with most locales only falling back into the mid/upper 60s to low
70s.

The weak cold frontal boundary will slow its forward progression and
stall out in the vicinity of the NY/PA line this morning. This
boundary is advertised to serve as the focal point for convection by
this afternoon. The coverage of thunderstorms and northern extend
for severe weather will greatly depend on the position of this
frontal boundary. That said...guidance continue to suggest that a
convectively enhanced wave will track along this boundary this
afternoon, along with a shortwave dropping out of the central Great
Lakes. These two feature could potentially enhance the SVR wx
potential. Sufficient shear looks to be present too, especially
along the Southern Tier, which lines up with the Marginal/Slight
Risk for severe storms issued by SPC in the Convective Outlook.

Overall...the greatest risk still remains across the Southern Tier
which lies closer to the track of the passing frontal wave. Outside
of the shower and thunderstorm chances, expect another day of temps
in the upper 70s to low 80s.

Tonight...showers and thunderstorm will decrease in coverage from
west to east. Northerly upslope flow and residual low-level moisture
behind the front will `likely` combine to keep much of the forecast
area blanked in a low stratus overnight. We even could see some fog
for areas that see precipitation. Outside of that...lows will be
found in the 50s to low 60s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Steadier showers and storms will continue into Wednesday evening
from the western Southern Tier into the Finger Lakes region as a
wave of low pressure moves northeastward along the slow-moving wavy
frontal boundary draped across this region. Scattered lighter
showers will also be possible for areas north of the boundary before
the frontal wave responsible for all of this activity exits east of
the area by the early overnight hours, allowing this initial wavy
cold front to finally press southward out of our area. Another
shortwave trough will then dive southeastward out of the upper Great
Lakes, crossing the eastern Great Lakes region late Wednesday night
and Thursday. This feature will also help force a secondary cold
front southeastward through western and northcentral NY late
Wednesday night through the midday/early afternoon hours on
Thursday. With deeper moisture associated with the initial wave
having departed to our east, not expecting more than some scattered
lighter showers/isolated rumble of thunder as the boundary passes
through the area, mainly from the Genesee Valley eastward. Depending
on the speed of the front, a few showers may linger across eastern
areas through late morning/early afternoon Thursday, with areas
toward the North Country/SL Valley continuing with at least the
slight chance for a few diurnally driven light showers through late
in the day as the southern periphery of the passing shortwave aloft
grazes northern NY. Otherwise, a much more refreshing airmass will
advect in across the region in the wake of the frontal passage as a
dome of high pressure builds in from the west bringing dry weather
through Friday with comfortable temperatures and humidity levels. In
fact, below normal temperatures are expected Thursday with highs
ranging from the upper 60s to low 70s. Similar to the first part of
the work week, high pressure then slides east of the area Friday
with a warming southerly return flow boosting temperatures back near
normal with highs mainly in the mid 70s to low 80s.

A weak mid level ripple and associated low level warm frontal
segment will cross the area Friday night, with increasing chances
for showers and a few thunderstorms from west to east as the night
wears on. Of note will be the very humid airmass that advects into
the area behind the frontal passage. Dew points mainly in the
comfortable low to mid 50s range late Friday will surge into the mid
60s to near 70 Saturday morning. This will keep lows Friday night on
the warm side, especially across areas south of Lake Ontario with
low temperatures only falling back into the mid and upper 60s, a tad
cooler across the North Country.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A well defined shortwave trough will cross the Great Lakes Saturday,
deepening an area of surface low pressure that will advance from the
northern Great Lakes through southern Quebec Saturday. A deep
southerly flow ahead of this trough will advance moisture northward,
increasing PWATs to nearly 2 inches across the eastern Great Lakes
region. Showers and thunderstorms are expected to form Saturday and
continue through the evening hours of Saturday before a cold front
crosses the region from west to east late. The timing of the cold
front, 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.

Behind the cold front a much drier airmass will settle upon the
eastern Great Lakes. We`ll still have to contend with a few showers
Sunday with the passage of the upper level trough, but drier air and
eventually cooler airmass (mid single digit Celsius 850 hPa
temperatures) will bring a cool night Sunday night with lows in the
mid 40s to mid 50s. Fair weather Monday, with comfortable dewpoints
in the 40s and 50s with high pressure nearby. Tuesday a return
southerly flow along with the approach of a shortwave from the west
may trigger a few showers or thunderstorms.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
A cold front will bring some showers or even an isolated rumble of
thunder this morning, which may bring some limited impacts for
terminals east of KROC to include KART. Ceilings will slowly lower
for a brief period this morning, with MVFR Cigs possible across the
S. Tier and east of Lake Ontario. Elsewhere, VFR is expected to
prevail.

The cold frontal boundary will stall across the region today, a wave
riding along this feature will then bring increasing chances for
showers and thunderstorms by this afternoon. Chances will be
greatest in the Southern Tier (KJHW) which may see periodic impacts
at terminals (MVFR to IFR). Confidence remains lower in shower and
thunderstorm coverage north of the S. Tier. Outside of the areas of
precipitation, VFR will prevail through the day.

Tonight...shower and storms will decrease in coverage but stratus and
fog may bring about MVFR-IFR Cigs and lower vsbys. This will
especially be the case across the higher terrain of the S. tier and
east of Lake Ontario.

Outlook...

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

&&

.MARINE...
Elevated south to southwest winds remain across Lake Erie and the
western end of Lake Ontario overnight and early this morning,
producing moderate chop on both lakes.

Lighter winds and wave action is expected by this afternoon but there
will be increasing chances of showers and thunderstorms.  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
NEAR TERM...AR
SHORT TERM...JM
LONG TERM...Thomas
AVIATION...AR
MARINE...AR