Irondequoit, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

309
FXUS61 KBUF 011042
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
642 AM EDT Thu May 1 2025

.SYNOPSIS...
A warm front will push its way across our region today and tonight,
with a noticeable milder day today...that will feature showers and
thunderstorms later this afternoon and evening. Strong to severe
storms featuring damaging wind gusts and hail over western New York
will wane tonight with the loss of daytime instability, but a
stalling cold front near our region will maintain chances for
showers Friday and Saturday, with a return of Atlantic moisture
through the weekend and early next week maintaining unsettled
conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
This early morning a surface low is located across the mid-
Mississippi Valley, with a warm front extending eastward across the
Ohio Valley. Isentropic lift and increasing moisture this morning
may yield a sprinkle near Lake Erie this morning, but largely our
region will remain dry until instability builds through the
afternoon and lift ahead of a shortwave trough nears our region.

An axis of MUCAPE values of 500 to 1000 J/KG will be oriented across
Lake Erie and into southern Ontario Canada this afternoon, and here
is where the stronger storms will be found. As lift ahead of a
shortwave trough nears our region this evening, increasing flow
aloft will increase moisture as well as the 0-6 km bulk shear
values to over 45 knots such that upstream clusters of stronger to
severe storms are expected to advance into our region, with activity
focused upon and south of a warm front that will be draped across
SW NYS. Damaging wind gusts will be the primary threat with these
storms, but MUCAPE values centered in the 9-11K feet range will also
lend to a hail potential. This hail potential will be greatest south
of Buffalo, and will continue to mention the small hail potential in
the forecast.

While the elevated instability will not be impacted by the cold Lake
Erie waters, the loss of daytime heating will allow for storms to
weaken through the evening hours...with the severe risk becoming
lower deeper into the evening hours and as storms advance eastward.

The center of a +2SD PWAT anomaly will be centered upon WNY with
storms later this afternoon and evening containing drenching
downpours. The flow aloft should keep storms moving, but any
training of storms as flow becomes parallel ahead of the late night
arrival of a cold front could bring ponding water and poor drainage
flooding. As the warm front lifts into the North Country later
tonight showers will expand to areas east of Lake Ontario, though
diminishing instability will keep the thunder potential to just a
slight chance. The southerly flow, with gusts into the 20 mph range,
will keep air temperatures mild tonight.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
A positively tilted upper level trough will dig across the upper and
central Great Lakes for the end of the work week. This will help
send a cold front attendant to low pressure moving through southern
Quebec close to or possibly into western NY Friday afternoon. This
will bring the next likelihood for showers and scattered
thunderstorms. With regard to severe weather, shear profiles are
decent, however better instability will be to our south and
southwest. Exact timing and position of the cold front along with
questions on amount of cloud cover will keep forecast confidence low
at this time. SPC does have areas from the Genesee Valley/Finger
Lakes region in a Day 2 Marginal Risk. With shear being the
principal driver, main threat would be the possibility for gusty
winds with any stronger storms that possibly develop Friday
afternoon into the early evening hours. Above average temperatures
with highs mainly in the upper 60s to mid 70s.

Upper level trough over the upper/central Lakes will sharpen through
the first half of the weekend, however make very little in the way
of eastward progress. Similarly at the surface, the cold front will
slowly sag across our area and become pretty much stationary while
gradually washing out Friday night through Saturday. Unfortunately,
while in the process of weakening, wave after wave will use this
boundary as a conduit bringing round after round showers and
embedded thunderstorms during this time. That doesn`t mean it will
rain all the time, so expect some periods of dry time in between
waves. Temps dip a bit below average Saturday with clouds and
showers, along with cooler air filtering in with the cold front.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Model consensus continues to trend more unsettled over western and
north-central NY for the long term period.

Initially Saturday night, what is left of the decaying cold front
will sag southeast and completely wash out, This may bring a brief
period of drying overnight, with the best chances across
northwestern areas furthest from the boundary. Meanwhile, forecast
confidence continues to increase on a large upper low cutting off
and wobbling about the Ohio Valley later Saturday night through
Monday night. Our area will remain on the northeastern periphery of
this feature, however now appears several pieces of shortwave energy
pinwheeling about the upper low may bring periods of showers across
our area through Monday night as they pass overhead. Similar to the
short term period, expect some periods of dry time built in. 01/00Z
medium range deterministic guidance showing fairly good consensus on
this scenario for the second half of the weekend into the first part
of the new work week. Further boosting forecast confidence, ensemble
guidance is also trending in this direction. Being that this is
quite the change and that we`re talking about a cutoff upper level
low 4 to 5 days out...which history shows that models have a
difficult time with, have raised PoPs into the Chc/high Chc range
for now, but expect these to continue to rise if this trend
continues.

Upper low will begin to slowly kick out of the Ohio Valley Tuesday,
however model guidance diverges some on the track of the upper low.
It will be an eastward track, but will it be a slow trek right
across our area through the latter half of the period, or will it
travel a bit north or south of our region. Either way, looks as
though will remain close enough to keep unsettled weather in the
form of periodic showers going through the second half of the
period. As mentioned, forecast models many times struggle with
evolution/track/strength/etc on cutoff upper lows, so stay tuned as
we get closer and the finer details become better resolved.

Daytime highs in the 50s Sunday, with mainly 60s for the first half
of the new work week.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
For the 12Z TAFs VFR flight conditions are found, and these
conditions will prevail for the next 6 hours or so. A warm
front and deeper moisture lifting into the region this morning
may bring a sprinkle to the western TAF sites near Lake Erie.

Light easterly winds this early morning will begin to veer to
southeasterly, and increase during the afternoon hours. Convection
is likely to enter our region later this afternoon, with
thunderstorms for KIAG/KBUF and KJHW possibly featuring gusty winds
and heavy busts of rain. Strongest storms between 20Z and 02Z...with
strong thunderstorms possibly reaching KROC this early evening
before weakening with the loss of elevated instability. A passing
shortwave coupled with a warm front lying across the North Country
will maintain shower chances through the night with MVFR/VFR flight
conditions. Southerly flow will feature light gusts into the low to
mid 20 knot range through the night.

Outlook...

Friday...MVFR/IFR with showers early and a chance for thunder,
improving to VFR/MVFR.
Saturday...MVFR/IFR with showers likely.
Sunday...Mainly MVFR/VFR with shower chances increasing.
Monday...IFR/MVFR with chances for rain showers.

&&

.MARINE...
As surface high pressure drifts to the east, an easterly flow will
strengthen over the Lower Great Lakes, with wind speeds reaching
small craft advisory range over the western waters of Lake Ontario
later today. As a warm front lifts northward across the Lower Great
lakes today these easterly winds will veer to southeast and then
southerly tonight, with the greater wave heights found over the
Canadian waters.

A cold front will move east across the eastern Great Lakes late
tonight and Friday. Southwest winds will increase along and behind
the front, with a round of Small Craft Advisory conditions likely on
both Lake Erie and Lake Ontario.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT this
         evening for LOZ042.

&&

$$

SYNOPSIS...Thomas
NEAR TERM...Thomas
SHORT TERM...JM
LONG TERM...JM
AVIATION...Thomas
MARINE...Thomas