WX in text

658
FXUS61 KBUF 282037
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
337 PM EST Tue Jan 28 2025

.SYNOPSIS...
After a brief break in the weather this afternoon...a fast-moving
clipper system will track from the Upper Great Lakes to New England
tonight through Wednesday...and in the process will bring us our
next round of widespread accumulating snowfall. Most areas will see
several inches of accumulation...with lake and terrain enhancement
resulting in greater accumulations east of both lakes. After a
relatively quiet day Thursday...a storm system passing by to our
south will then bring milder temperatures and a mix of rain and snow
to end the work week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of this writing dry and quiet weather is in place areawide...
along with a mix of partly to mostly sunny skies. Expect dry weather
to persist through mid to late afternoon...along with a general west-
east increase in cloud cover. Temps will be on the cold side of
normal...with highs ranging from the teens across the North Country
to the lower-mid 20s elsewhere.

Conditions will then quickly deteriorate from west to east late this
afternoon and evening...as a robust...fast-moving clipper system
quickly slides southeast from the Upper Great Lakes. Moderately
strong H925-70 frontogenetic forcing...especially northeast of the
Genesee valley...will combine with the lift underneath the left
front exit region of a 140kt jet to generate a widespread general
snowfall of about two to four inches over the region tonight. This
being stated...orographic and lake enhancement (with temps aloft not
cold enough to support true lake induced convection) will support
higher amounts of up to five inches over the higher terrain east of
Lake Erie...and as much as six to eight inches across the Tug Hill
region east of Lake Ontario. Additionally...increasingly brisk
southwesterly to westerly winds will gust to 25-35 mph as we push
through the late evening and early overnight hours...leading to the
development of areas of blowing and drifting snow from west to east.

On Wednesday...the clipper system will become increasingly broad/
double-barrelled as it exits across New England and into the
Canadian Maritimes. Copious moisture in its wake will be lifted by a
vigorous shortwave and trailing cold front...helping to generate
another 1 to 3 inches of snow in most areas. This being said...
upsloping and lake enhancement will again support higher amounts
east of both lakes...particularly across the Tug Hill and western
Adirondack foothills where additional fresh accumulations of 5 to 10
inches appear likely. East of Lake Erie amounts will be lower in
comparison...but should still average another 2 to 4 inches.
Otherwise brisk westerly to west-northwesterly winds gusting to 30-
40 mph in most places will continue to produce areas of blowing and
drifting snow...particularly to the south of Lake Ontario. The
highest overall gusts (to 45 mph or so) will be found along and a
little inland from the south shore of Lake Ontario.

Taking all of the above into consideration...a Winter Storm Warning
remains in place for the eastern Lake Ontario Region through 1 AM
Thursday...with this time extended a bit outward from the original
Watch to account for some upslope/lake effect snows that will linger
through the first half of Wednesday night. Meanwhile Winter Weather
Advisories are in effect for all other areas...with most of these
running through 6 pm Wednesday. The one exception to this for Wayne
and Northern Cayuga counties...where the advisory runs until 4 am
Thursday to account for lingering modest lake snows southeast of
Lake Ontario.

With respect to temperatures...the warm advection regime attendant
to the approaching clipper will result in very early evening low
temperatures that will be very close to today`s highs...followed by
a marked non-diurnal temperature trend for the rest of tonight. This
will result in readings quickly climbing to the mid to upper 20s
east of Lake Ontario and to the upper 20s/lower 30s elsewhere as we
push through the night...with highs on Wednesday then expected to
range mostly in the upper 20s to mid 30s.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
Departing mid- level trough axis across New England into the
northern Atlantic Wednesday night and Thursday will support,
surface low pressure to pull northeast into the Canadian
Maritimes, supporting cold northwesterly flow to spill across
the region. This will result in some lake effect/upslope snow
showers southeast of both lakes at nightfall. This activity will
gradually wane throughout the night as a drier arctic air mass
filters in across the area. This being said, just a couple of
inches expected southeast of the lakes Wednesday night, with the
location of maximum snowfall lying southeast of Lake Ontario.

A ridge of surface high pressure will then slide east across the
eastern Great Lakes Thursday, supporting a brief period of dry
weather.

Eyes then turn to two different mid-level features heading east
Thursday night. The first of which is a mid-level trough in the
northern branch of the jet stream. This will support a surface low
to slide east across southern Canada and slide a warm front across
Lake Ontario, and result in the chance for a few snow showers across
the eastern Lake Ontario region Thursday evening.

Then, eyes turn towards the closed low with in the southern branch
of the jet stream tracking northeast across the Mississippi Valley
towards New England, resulting in a surface low to follow a similar
track Thursday night through Friday. As this low crosses the Ohio
Valley and into New England, the chance of precipitation will
increase from west to east Thursday night into Friday, with the best
chances lying across the areas south of the NYS Thruway (I-90).
Should note that with this system also brings a milder air mass,
resulting in warm air advection Thursday night through Friday, thus
supporting a non-diurnal temperature trend Thursday night with lows
occurring early in the evening before temperatures surge into the
low to mid 30s. Temperatures will continue to remain on the warm
side for the end of January/start of February with highs Friday
warming up into the mid to upper 30s. Due to the warmer airmass
Thursday night and Friday, a mix of percipition type (snow and
rain) will be likely especially across the typical warmer locations
across the Finger Lakes region.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Strong sfc high pressure builds southeast across the Lower
Lakes on Saturday. Any lake induce snow showers southeast of the
lakes will rapidly weaken as eq-levels fall and then end as
drier air continues to filter in Saturday afternoon. We should
also see some clearing take place with partly sunny skies but it
will be chilly with a `cold` airmass in place (H850 T`S -14C to
-19C). High Saturday will be found in the teens for most
locales, a few mercury readings may top out in the low 20s (S.
Tier).

Sfc high pressure rapidly departs off to our northeast into New
England Saturday night but will maintain dry weather. Cold night
with lows ranging from below zero east of Lake Ontario to single
digits to low teens elsewhere. The next system nears the eastern
Great Lakes Sunday. It is at this juncture where models are not in
sync. There is issues with timing, QPF amounts, overall strength,
and then track of the next low pressure system. Given the overall
uncertainty have held close to NBM guidance and made very few
changes Sunday and beyond. That said...the pattern does appear to
remain active.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
Through mid to late afternoon...expect dry VFR conditions to prevail
across most of the area...along with a gradual increase/thickening
in cloud cover from west to east.

Conditions will then quickly deteriorate very late this afternoon
and this evening as a fast-moving clipper system slides from the
Upper Great Lakes to the vicinity of Lake Ontario. In the process...
this system will bring a widespread light to moderate snowfall to
our region...with visibilities/ceilings dropping to IFR and MVFR
respectively. Within the steadiest snow...a period of LIFR
visibilities will be possible. Winds will also pick up out of the
west as the night progresses...leading to some areas of blowing and
drifting snow.

On Wednesday the clipper system will exit out across New England...
with its trailing cold front and an attendant disturbance pushing
across our area from northwest to southeast. This will generate
continued light to moderate snow/snow showers and associated IFR
visibilities/MVFR ceilings...with terrain and lake enhancement
resulting in the steadiest snow being found east of both lakes. At
the same time...brisk westerly to west-northwesterly winds will also
help to generate some areas of blowing/drifting snow. Late in the
day the snow will begin to taper off across the Niagara Frontier...
thereby allowing conditions to improve to VFR at KBUF/KIAG.

Outlook...

Wednesday night...Lingering snow showers and IFR east/southeast of
the lakes gradually diminishing from west to east...otherwise
improving to VFR.

Thursday...VFR with a chance of snow showers/MVFR southeast/east of
Lake Ontario.

Friday...IFR/MVFR in a mix of rain and snow.

Saturday...Mainly VFR with a chance of morning snow showers south of
Lake Ontario.

Sunday...VFR/MVFR with a chance of rain and snow showers.

&&

.MARINE...
Moderately brisk west-northwesterlies across Lake Ontario will
subside further and back to the southwest through the afternoon
hours...with this coming courtesy of a quick-moving weak bubble of
high pressure.

After a brief lull in the winds late this afternoon and early this
evening...the next storm system will quickly slide southeast from
the Upper Great Lakes. This will allow winds to freshen during the
course of tonight...with strong westerlies in place areawide by
daybreak Wednesday. Strong westerlies will then persist through the
day Wednesday...before diminishing from west to east Wednesday night
as high pressure builds across the Lower Great Lakes. Given all
this...have extended the existing Small Craft Advisories for Lake
Ontario further out in time to cover this next round of stronger
winds and associated wave action...while also adding new Advisories
for Lake Erie and the Niagara River.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory until 6 PM EST Wednesday for
     NYZ001>003-010>014-019>021-085.
     Winter Weather Advisory until 4 AM EST Thursday for NYZ004-005.
     Winter Storm Warning from 7 PM this evening to 1 AM EST
     Thursday for NYZ006>008.
MARINE...Small Craft Advisory from 9 PM this evening to 7 PM EST
         Wednesday for LEZ020.
         Small Craft Advisory until 1 AM EST Thursday for LEZ040-
         041.
         Small Craft Advisory from 9 PM this evening to 10 PM
         EST Wednesday for LOZ030.
         Small Craft Advisory until 7 AM EST Thursday for LOZ042.
         Small Craft Advisory until 1 PM EST Thursday for LOZ043-
         044.
         Small Craft Advisory until 10 AM EST Thursday for LOZ045.

&&

$$

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

NWS BUF Office Area Forecast Discussion