Buffalo, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

224
FXUS61 KBUF 180549
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1249 AM EST Sat Jan 18 2025

.SYNOPSIS...
Our spell of uneventful weather will persist through tonight...then
a strong arctic cold front over the Upper Great Lakes will plow
through the region on Saturday. The mixed rain and snow that will
accompany the front will change to just snow in the deepening cold
air in its wake...then out sites will be set on plummeting
temperatures Saturday night through the first half of the new work
week. The coldest air in more than five years will build over the
region Monday into Wednesday...and this will result in dangerously
low apparent temperatures regionwide...along with accumulating lake
snows east and northeast of the lakes.

&&

.NEAR TERM /THROUGH TODAY/...
IR satellite imagery shows a break in the clouds across western NY
late tonight. This will move east while mid to high level clouds
fill into this break further east. Downsloping is contributing to a
mild night across lower elevations. Gusty conditions will continue
with gusts up to 40 mph along the Lake Erie shoreline into southern
Erie county overnight.

Expect a brief break in active weather tonight...as high pressure
will continue to drift off the East coast. Meanwhile, a digging
upper level trough across central North America will push an arctic
cold front across the Upper Great Lakes. With the area sandwiched
between the front and the exiting aforementioned surface ridge,
deep/strengthening southerly flow will support a warm advection
regime, thus resulting in a non-diurnal temperature curve tonight.
Lows tonight will occur early this evening (ranging from the upper
20s to low 30s across the high terrain and the mid to upper 30s
elsewhere) and warm up into the mid to upper 30s areawide by
daybreak. Otherwise outside of the warming temperatures, expect dry
weather to prevail.

Saturday, the rapidly intensifying upper level trough will continue
to dig southeastward across the Great lakes, supporting its
attendant surface low over Quebec to gradually pivot its trailing
arctic cold front eastward across the lower Great Lakes late Saturday
morning and Saturday afternoon. Sufficiently deep moisture and lift
along the cold front and front flank of the parent upper level
trough will lead to fairly widespread precipitation spreading from
west to east throughout the day Saturday. This being said, with the
mild air mass in place onset of the front, precipitation type will
be a rain-snow mix. A changeover to all snow will happen fairly
quick with the arrival of the cold air in addition to wet-bulbing
effects. Depending on the timing of the changeover, snowfall amounts
will vary, with higher amounts likely with a quicker changeover,
though in general, snowfall amounts will generally be higher across
the higher elevations where thermal profiles will trend cooler and
snow remaining the dominant precipitation type. With this forecast
iteration, snowfall amounts range between 1-3" across the higher
terrain east of Lake Erie and 2-4" across the southern slopes of the
Tug Hill Plateau. Otherwise, a general inch is likely elsewhere,
with the northern Finger Lakes remaining the warmest and therefore
will see little to no snow accumulations.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
...BECOMING BITTERLY COLD WITH LAKE EFFECT SNOW EARLY NEXT WEEK...

Residual northwest flow lake effect/upslope snows will linger
through much of Saturday night, though with lessening intensity as
synoptic moisture will be scouring out within the post-frontal
airmass. Additional minor accumulations under an inch are likely,
though could more in the way of 1-2" up on the Tug Hill/Western
Dacks. Deep CAA will lead to a much colder night with lows falling
back into the teens.

Deep troughing will engulf across much of the CONUS heading into
Sunday as cross-polar flow allows a frigid arctic airmass to dig
southward across the Upper Midwest. To the southeast, the cold front
now moving into the Carolinas will be interacting with a warm
maritime airmass off the Southeast coast, leading to a strengthening
area of low pressure. The sfc low is then expected to ride northeast
off the Mid-Atlantic coast by Sunday evening, arriving in the
Canadian Maritimes by Monday morning. A general northern trend noted
among the latest guidance packages in the system`s track, with an
increase in overall QPF as well, though the Canadian model continues
to be the outlier as it advertises a much further westward track.
Given the notably higher 75th-25th percentile spread in the GEPS and
that the further eastward ENS/GEFS are in much better agreement with
one another, will continue to lean on the latter. This would favor
the greatest direct impacts from this system remaining well south
and east of our area, though it is looking increasingly likely that
some lighter synoptic snow will manage to spread into the region on
Sunday. Daytime snowfall amounts should be minor, generally up to an
inch in most areas, though enhancement from the lakes could lead to
a few swaths of 1-2" totals. Otherwise...Highs on Sunday will be
cold, ranging from the teens to low 20s.

As the system continues to move northeast towards the Canadian
Maritimes Sunday night, it will begin to wrap the arctic air to our
west into the Great Lakes. Though, it will already be plenty cold
enough aloft heading into the night to support additional lake
effect and upslope snows as the flow backs from north to
northwesterly overnight. Some of the hi-res guidance (CMCreg/NAM)
advertise a mesolow moving through overnight, which could also bring
additional snow showers outside the main lake effect areas. Winds
will become more well-aligned down the long axis of both lakes as
the frigid air pours into the region along an arctic front during
the day Monday. The west-northwesterly flow will initially direct
steadier lake snows into the Southern Tier and southeast of Lake
Ontario Monday morning. As winds turn more southwesterly (260/250)
across the lakes, off Lake Erie this should place the band between
northern Chautauqua/Cattaraugus and the Buffalo Southtowns, while
off Lake Ontario the favored placement looks to be in the vicinity
of the Oswego/Jefferson county line. At this juncture, it looks as
though the bands will persist in these general regions through
Monday night, though it should be stated here that there is still
uncertainty in exact band placement and intensity. Model soundings
indicate marginal amounts of moisture through the DGZ over Lake Erie
in particular, which could prove to be a limiting factor, as well as
the potential for the band to edge a little further north into
Northern Erie county.

With the aforementioned uncertainties, estimating snowfall amounts
within these bands are still a bit difficult to pin down at this
range. The setup over Lake Ontario looks better in regards to the
potential for more significant snowfall amounts and rates,
especially later Monday and Monday night. Depending on how
stationary the band is, could see totals in the vicinity of the Tug
Hill Plateau quickly approach or even exceed a foot by daybreak
Tuesday. Totals are currently much lower in comparison off Erie,
though this will ultimately hinge on band residence time and if
enough moisture will be available to support higher rates.

In regards to temperatures...850H temps around -20C to start the day
Monday are expected to crater down to around -25C by Monday night.
With a stiffening pressure gradient between high pressure nosing in
from the Ohio Valley and the low over the Canadian Maritimes, wind
chill values are expected to be sub-zero east of Lake Ontario by
Sunday evening, then everywhere else by early Monday morning.
Apparent temps are expected to remain below zero through Monday
night, and be WELL into the negative teens by Tuesday morning.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
...FRIGID COLD AND BOUTS OF LAKE EFFECT SNOW CONTINUE THROUGH EARLY
NEXT WEEK...

An arctic airmass will remain over the forecast area Tuesday through
at least Wednesday night as deep longwave troughing remains
entrenched across much of the Lower 48. Air temperatures to start
this period will be in the low single digits across the lower
terrain and sub-zero elsewhere, with wind chills well into the
negative teens and even negative 20s. 850H temps around -25C will
greatly inhibit how warm it will get at the sfc, with highs only in
the single digits to low teens Tuesday and Wednesday, though
Wednesday will likely be a few degrees "warmer" in comparison.
Tuesday night looks to be the coldest period during this arctic air
outbreak, with air temps expected to be below zero just about
everywhere and wind chills from -15F to -25F overnight.

In addition to frigid wind chills, lake effect snows are expected to
continue through the mid-week timeframe. Higher uncertainty in this
timeframe on exact placement of the bands and therefore potential
snowfall amounts, though west-southwesterly flow should direct the
heavier snows east to northeast of both lakes into Tuesday night.
Long range guidance indicates that these snows could impact the same
areas as those that received snow later Monday and Monday night with
the continued potential for more impactful accumulations and
snowfall rates, especially off Lake Ontario on or near the Tug Hill.

A sfc-850H ridge will then build over the lakes later Wednesday into
Thursday. This will not only weaken and shift the overall lake
response further north but also lead to a warming trend. That is to
say, temperatures are expected to remain below normal, though highs
Thursday and Friday are expected to range in the 20s as opposed to
single digits.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A southerly low level jet and VFR conditions will continue across
western and north central NY overnight. Wind gusts around 25 kts are
possible at the TAF sites with higher gusts along the Lake Erie
shoreline. Low level wind shear will be present for those places not
mixing overnight.

A strong cold front will move across the region Saturday.
Precipitation will move into western NY Saturday morning and spread
east across the forecast area. Marginal surface temperatures will
result in a rain and snow mix at lower elevations and snow across
higher elevations including KJHW. Flight conditions will deteriorate
and widespread MVFR/IFR conditions are expected at the TAF sites.
Model guidance is showing IFR conditions at KART Saturday afternoon.
Leaned less aggressive in pre-frontal conditions as downsloping will
likely keep them at MVFR.

Any mix of rain and snow will transition to snow Saturday afternoon
into the evening. Widespread snow will move east with lingering lake
effect and upslope snow showers Saturday night. MVFR/IFR conditions
will continue across the TAF sites.

Outlook...

Sunday...VFR/MVFR with a chance of snow showers.
Monday through Wednesday...Local LIFR in lake effect snow east
of the lakes, mainly VFR elsewhere.

&&

.MARINE...
Occasional moderate southwest to west winds will continue to bring
Small Craft Advisory conditions on Lake Erie much of the time
through Saturday night. A brief period of marginally strong enough
westerlies will also produce some lower-end advisory-level
conditions along the southeastern shore of Lake Ontario today, with
strengthening southerly flow then bringing a period of advisory-
worthy conditions to far eastern Lake Ontario tonight and Saturday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 10 PM EST this evening for LEZ040-
         041.
         Small Craft Advisory until 4 PM EST this afternoon
         for LOZ045.

&&

$$

SYNOPSIS...RSH
NEAR TERM...EAJ/HSK
SHORT TERM...PP
LONG TERM...PP
AVIATION...HSK
MARINE...EAJ/JJR