947
FXUS61 KBUF 230224
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1024 PM EDT Sat Jun 22 2024

.SYNOPSIS...
The end is near. That is...the end of the heat wave. While it will
be quite warm and humid through Sunday...a cold front will push
through Sunday afternoon with some fairly widespread showers and
drenching thunderstorms. Cooler and less humid air will follow to
start the new work week...but the relief will be relatively brief as
very warm weather can be expected Tuesday and Wednesday. The
temperature roller coaster ride this coming week will then head back
downhill to end the week with highs mainly in the 70s Thursday and
Friday.

&&

.NEAR TERM /UNTIL 6 PM SUNDAY EVENING/...
A stationary front is stretched west to east tonight...roughly along
the southern shore of Lake Ontario.

As we push through the night...the instability to the south of this
boundary will continue to diminish. Meanwhile...the surface boundary
will gradually be pushed north...courtesy of a surface low that is
strengthening over the central Great lakes. This will place more of
the region within a warm sector. While a shower or thunderstorm
cannot be completely ruled out to the south of the boundary (ie. wrn
counties)...the majority of any shower and possible thunderstorms
will be found across the North country. Otherwise...some patchy fog
may occur in areas which received rain during the day. Overnight
temperatures will be muggy and generally in the lower to mid 70s,
with some upper 60s across the Southern Tier and east of Lake
Ontario.

A VERY active weather day is then expected on Sunday, especially
during the midday and afternoon. A potent upper shortwave and
associated deepening surface cyclone tracking from the central Great
Lakes along the international border. A pre-frontal trough will work
into the region early in the day ahead of the main of the cold front
which tracks into the region late in the day.

There may be two rounds of convection, first with the pre-frontal
trough and then ahead of the cold front later in the afternoon.
Surface instability will certainly be present with SBCAPES forecast
to be near 2000 J/KG. Shear profiles become increasingly favorable
with around 35 knots of flow at 850 mb and near 50 knots at 500 mb,
with some turning with height allowing hodographs to lengthen with
time. SPC has maintained a Slight Risk for severe storms for much of
the area inland from the lakes. Main threat looks to be damaging
winds, with a lesser threat of large hail, but with the lengthening
hodographs could see an isolated supercell. Heavy rain potential is
there with high atmospheric moisture content, but the convection
should be progressive making the flash flood threat more limited.

&&

.SHORT TERM /6 PM SUNDAY EVENING THROUGH TUESDAY/...
A fairly fast quasi-zonal flow will be in place for the upcoming
work week, as the strong upper level ridge that brought the
oppressive heat and humidity to the region this past week is
suppressed over the southern half of the CONUS. Overall, there
looks to be bouts of comfortable temperatures along with periods
of more typical mid summer warmth ahead of a couple cold frontal
passages...one mid week and the second toward next weekend. This
will also translate to periods of dry time, with storm chances
ramping up along and ahead of the aforementioned frontal
boundaries. The details...

A few strong storms (gusty winds/heavy rain) will remain possible
into Sunday evening, mainly east of the Genesee Valley, as the lead
shortwave and accompanying surface cold front push into eastern NY.
However, a trailing shortwave will strengthen as it digs across the
central Great Lakes first half of Sunday night, then crosses the
lower Great Lakes later Sunday night and Monday. This will keep the
threat for at least scattered showers/isolated non-severe
thunderstorms in the forecast through the start of the new work
week. Likelihood for showers will be greatest east of Lake Ontario
closer to the better dynamics/lift and moisture associated with this
feature. Some gusty NW winds will also be possible on Monday as
boundary layer flow increases with the passage of the trough. There
is still some good news for those looking for a break from the
oppressive heat and humidity as a cooler and less humid airmass
moves into the region. Lows Sunday night will drop back into the
upper 50s to lower 60s for much of the area. Highs Monday will range
mainly from the upper 60s to mid 70s, with dew points dropping into
a more comfortable range, mainly in the mid to upper 50s.

High pressure is then slated to cross the area Monday night and
Tuesday bringing a brief period of well deserved quiet weather. A
comfortable Monday night with lows generally in the 50s, with some
low 60s closer to the lakeshores. Flow will then shift back to the
southwest on Tuesday as a return flow sets up on the back side of
the surface high as it slides southeast of the area. This will boost
high temperatures back into the low to mid 80s for the majority of
the region, although humidity levels will remain tolerable.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
As mentioned above, the quasi-zonal flow will continue with a
similar weather pattern to the Short Term expected through this
period. The details...

A weak mid level ripple will move across the area Tuesday night,
while a low level warm frontal segment moves northeast across the
region. PWATs increase to near 1.5 inches, however lack of forcing,
not expecting much more then some scattered showers/isolated rumble
of thunder overnight.

Next round of more significant weather looks to be centered around
the Wednesday timeframe as showers and storms accompany the next
cold frontal passage. Way to early to get into severe weather probs,
but will need to be monitored. Timing/etc still a bit in question as
well. Of more certainty is the return of mid summer warmth and
humidity. Highs will be upper 70s to mid 80s, with dew points
climbing into the mid and upper 60s.

High pressure then looks to build in bringing another much more
refreshing airmass back into western and northcentral NY for the
latter part of the work week. This should result in mainly dry
weather Thursday and Friday with highs low to mid 70s Thursday, then
tacking on several degrees for Friday as airmass starts to modify
with surface high moving east of our area. Dew points in the 50s
will mean very tolerable humidity levels for late June.

Mid summer warmth and humidity along with shower/storm chances then
look to return as we head toward the first half of next weekend as
the next frontal system approaches from the west.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
While VFR conditions will be in place overnight...some areas may
develop some fog where the thunderstorms moved through during the
evening hours.

Sunday will then be QUITE active across western and north central
New York...as a cold front will sag through the region with numerous
showers and drenching thunderstorms. Along and behind the frontal
boundary...CIGs will drop off to between 700 and 1500 ft. This will
generally take place after 15z.

Outlook...

Sunday night...MVFR to IFR conditions early with showers tapering
off from west to east...then LIFR to IFR Cigs late.
Monday...Mainly VFR. A chance for afternoon and evening thunderstorms
inland from the lakes.
Tuesday...Mainly VFR conditions.
Tuesday night and Wednesday...MVFR/VFR with a chance for showers and
thunderstorms.
Thursday...Mainly VFR.

&&

.MARINE...
Light winds and minimal wave action is expected to continue across
the lower lakes overnight.

A cold front will approach the region Sunday with increasing
southwest winds which will likely bring a period of small craft
conditions, especially on the east end of Lake Erie. A round or two
of thunderstorms Sunday will bring the potential for locally strong
winds and waves.

Northerly flow behind the cold front will then bring continued
choppy conditions to the lakes through Monday. High pressure builds
in late Monday with diminishing winds and waves for Tuesday.

&&

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

&&

$$

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