Tonawanda Town, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

552
FXUS61 KBUF 041031
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
631 AM EDT Mon May 4 2026

.WHAT HAS CHANGED...
Increased winds and gusts a bit further for today, particularly
across areas northeast of Lake Erie.

&&

.KEY MESSAGES...
1) Warmer and breezy/windy conditions into Tuesday, with much cooler
temperatures returning by midweek.

2) Increasingly active weather returns tonight and Tuesday, with
another soaking rainfall expected later Tuesday into Wednesday.

&&

.DISCUSSION...
KEY MESSAGE 1...Warmer and breezy/windy conditions into Tuesday,
with much cooler temperatures returning by midweek.

Through Tuesday...reloading longwave troughing over central Canada
will gradually dig southeastward across the Upper Great Lakes...with
an associated surface low making its way from western Ontario
Province to northern Quebec...and its trailing cold front slowly
easing its way southeastward across our region Tuesday afternoon and
evening. Prior to the passage of this boundary...our region will
remain embedded within the deep southwesterly flow found between the
surface low/cold front and high pressure over the western
Atlantic...which will act to pump progressively warmer air across
our region through early Tuesday.

With 850 mb temps climbing to between +7C and +10C by later today
and then peaking around +10C later tonight and early Tuesday...it
should certainly feel a lot more like May between now and Tuesday
morning. Given good mixing along with increasing amounts of sunshine
today...the above should support highs mostly in the upper 60s to
mid 70s...with downsloping leading to the warmest readings across
the Genesee Valley and Finger Lakes. Lows tonight will then range
through lower 50s across the North Country to the mid-upper 50s
elsewhere. Given some continued uncertainty in the exact timing of
the cold front and its associated pcpn...there is some corresponding
uncertainty and resultant forecast bust potential with respect to
both the magnitude and timing of our high temps on Tuesday...with an
earlier fropa/pcpn onset favoring cooler temps and a later timing
favoring warmer readings.

With a relatively tight pressure gradient in place between the
surface low/cold front to our northwest and ridging over the western
Atlantic...we can also expect fairly breezy to windy conditions to
persist up until the cold frontal passage. Prior to that time a few
low level jet segments will also brush/slide across our northwestern
periphery...thereby leading to some periods of windier conditions
northeast of the lakes. The strongest overall winds may actually
come today northeast of Lake Erie...when good diurnal heating should
help to more effectively mix higher momentum air aloft associated
with a passing 30-40 knot LLJ segment down to the surface. As such
expect surface winds to gust to as high as 40 mph or so across the
Niagara Frontier...with some 30-35 mph gusts extending as far east
as Rochester/the Lower Genesee Valley. As we move into tonight...the
loss of heating and continued warm advection should help to better
inhibit the mixing of winds from another...stronger passing LLJ
segment down to the surface...though breezy conditions will still
persist. Renewed diurnal warming may then allow for another period
of windier conditions to develop downwind of the lakes Tuesday...
though the exact magnitude and timing of this remains in question
given the uncertainty in the timing of the cold front mentioned
above. For now...have capped gusts on Tuesday to the 30-35 mph range
given this uncertainty.

Following the passage of the cold front...upper-level troughing and
much cooler air will overspread our region again Tuesday night
through Friday...then will remain in place through at least the
upcoming weekend. This will result in another round of below normal
temperatures throughout this time frame...though these may not be
quite as cool as what we just experienced last week.

KEY MESSAGE 2...Increasingly active weather returns tonight and
Tuesday, with another soaking rainfall expected later Tuesday into
Wednesday.

While the passage of a weak shortwave trough may produce a few
more showers early this morning (mostly from Lake Ontario
northeastward across the North Country)...conditions should mostly
be dry today. This will start to change tonight into Tuesday morning
though...when the passage of another warm frontal segment will bring
the potential for some additional scattered to numerous showers...
with an isolated weak thunderstorm or two also possible given the
presence of some weak to very modest instability. Things will then
trend more markedly downhill Tuesday afternoon into Wednesday as
the cold front slows down and becomes increasingly wavy as it passes
through/just to the east of our area. Increasing deep-layer ascent
attendant to these features and PWATs climbing to around/a little
over 1 inch will support the development of widespread showers Tuesday
afternoon into Tuesday evening...when some weak to modest instability
may also support the potential for some isolated to scattered
thunderstorms...particularly from the Southern Tier northeastward
across the Finger Lakes and into the North Country. As we get into
the cooler air on the backside of the front and a surface wave ripples
by just to our southeast...the showers will then tend to evolve into
more of a stratiform rain later Tuesday night into Wednesday morning...
with the rain then tapering off Wednesday afternoon/night following
the passage of this wave.

All of the above will add up to another widespread soaking rainfall
from Tuesday through Wednesday...with 36-hour basin-average rainfall
amounts still looking to range on the order of 0.75"-1.25" per the
latest suite of guidance...and locally higher amounts remaining
possible if any localized convective enhancement can develop. That
said...with this next shot of rain coming some 5-7 days after our
last soaking rainfall...such basin-average amounts would be unlikely
to cause any hydrologic issues.

Finally...given the relatively fast low-mid level flow that will be
in place out ahead of the cold front...there may actually be a low-
end risk for a few strong to marginally severe storms Tuesday
afternoon/evening provided enough instability can develop. This will
mainly be the case from parts of the Finger Lakes northeastward
across the North Country...where instability should be the greatest,
and where SPC has introduced a Marginal Risk area in their latest
Day 2 Convective Outlook. Should this materialize...strong wind
gusts would be the primary severe weather threat...with large hail a
secondary risk given sufficiently cool temps well aloft.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR flight conditions will prevail through today as a warm front
brings periods of mid level clouds. A few showers are possible, but
VSBY restrictions are expected to remain AOA 6SM. A persistent low
level jet will maintain southwest wind gusts of 15-25 knots through
today. These gusts will increase to near 35 knots at KBUF and KIAG
after 16z.

Outlook...

Tonight...VFR/MVFR. Increasing chances for showers.

Tuesday...MVFR. Coverage of showers increases, with a few
thunderstorms possible in the afternoon

Tuesday night...Mainly IFR with widespread rain.

Wednesday...Improvement to MVFR/VFR possible with steady rain
tapering off. Low-end chance for showers lingers.

Thursday...VFR/MVFR with a chance of showers.

Friday...Restrictions possible with increasing chances for showers
in the afternoon.

&&

.MARINE...
Through Tuesday high pressure will slide across western Atlantic
while low pressure tracks across northern Ontario and Quebec...with
a slow-moving cold front crossing our region Tuesday afternoon and
evening. Periods of moderately brisk southwesterly flow are expected
at times out ahead of this front...bringing the likelihood for
rounds of near-SCA to SCA conditions. These are most likely across
Lake Erie, the Upper Niagara River, and the eastern end of Lake
Ontario given the onshore wind component.

A few thunderstorms and locally higher winds/waves will also be
possible on Tuesday with the approach and passage of the cold front.

&&

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

&&

$$

DISCUSSION...JJR
AVIATION...TMA
MARINE...JJR/PP