Forecast Discussion

000
FXUS61 KBUF 282016
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
416 PM EDT Tue Mar 28 2023

.SYNOPSIS...
High pressure will slide east across the Great Lakes tonight before
a sharp cold front produces rain and snow showers and gusty winds
late Wednesday and Wednesday night. A storm system over the
weekend could bring another round of strong winds.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Spotty light rain showers mixed with a bit of snow or graupel will
continue for a bit longer this afternoon south of Lake Ontario,
as daytime heating bubbles up residual low level moisture. High
pressure will build across the Great Lakes advecting in drier
air. The incoming drier air will help to gradually clear out
the overcast into early this evening. Some of the higher
terrain south of Lake Ontario could take a little longer within
a weak northerly upslope flow.

Mainly clear skies and dry weather will then continue overnight
tonight as high pressure slides overhead. Lows temperatures
will drop back into the mid to upper 20s, with a few locations
right along the lakeshores staying in the lower 30s.

...Snow squalls and rapidly falling temperatures late Wednesday...

High pressure slides east of the area early Wednesday keeping the
area dry into the early afternoon, but eventually giving way to
a sharp arctic cold front. This front will charge across the
area from northwest to southeast Wednesday afternoon through
early Wednesday evening, in the general 4 pm-7 pm time frame.
This will certainly have an impact on the Wednesday evening
commute across the entire area.

Along and just ahead of the front there will be enough support and
instability to develop a narrow band of moderate to heavy showers
with even the potential for some thunder, as lapse rates steepen
sufficiently to potentially overcome only minimally forecasted
CAPE. Temperatures ahead of the front likely reaching into the
lower to mid 50s, especially across the Genesee Valley and
western Finger Lakes. Immediately behind the front the rain will
change rapidly to a brief period of moderate to heavy snow with
a solid potential for snow squalls. Winds will become very
gusty immediately ahead and immediately behind the front as
strong winds aloft mix down within the convective elements. Not
completely out of the question that some damaging wind gusts
could occur. Temperatures behind the front will drop some 25
degrees within about a 2 hour period, bringing some concern for
a possible flash freeze of any lingering moisture on roadways.

850 mb temperatures eventually falls to near -15C later Wednesday
night as the front settles well south of the area. Northwest
flow lake effect snow showers are possible southeast of Lake
Ontario, but rapidly building high pressure along with subsidence
and notably drier air will limit the lake effect snow potential.
Overnight temperatures will fall back into the teens and 20s,
but gradually lowering northwest winds will create winds chills
as cold as the single digits.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
During the course of Thursday high pressure and much drier air will
rapidly build east across our area. Lingering cold northwesterly
flow and leftover low level moisture may still be enough to produce
some spotty morning flurries and snow showers southeast of Lake
Ontario...before further drying and subsidence bring about a return
to dry weather areawide for the afternoon. Otherwise it will be a
partly to mostly sunny and chilly late March day with highs ranging
from the low-mid 30s east of Lake Ontario to the 35-40 range
elsewhere. Thursday night the axis of the surface ridge will slide
eastward into eastern New York and western New England...with good
radiational cooling initially allowing for evening low temperatures
ranging from the upper teens/lower 20s across the North Country to
the mid/upper 20s elsewhere. During the second half of the night...
developing southerly return flow on the backside of the ridge will
then allow for rising temperatures...particularly across far western
New York where readings should reach the mid-upper 30s by daybreak.

Friday through Saturday night another southern stream mid-level
trough will race northeastward from the central Rockies to the
central Great Lakes by Saturday morning...before merging with the
base of a corresponding northern stream trough and ejecting out
across Quebec and the Canadian Maritimes through the rest of the
period. At the surface...there is increasing confidence that a
deepening cutter-type low will follow along a similar path through
Friday night before passing by a bit to our northwest Saturday...
then out across Atlantic Canada Saturday night. Such a track would
be favorable for another round of potentially strong to high winds
Saturday and Saturday evening...with the medium range guidance
packages continuing to show some differences in the exact track/
strength of the low and consequently the degree of the potential
wind threat we can expect.

Out ahead of this system...strengthening warm air advection and
deepening moisture will bring a return to much warmer temperatures
and periodic rounds of fairly widespread showers (along with general
pcpn amounts of one to two thirds of an inch) between Friday and
Friday night...with the precip possibly beginning as a little light
snow before changing over to all rain during the course of Friday
morning. With south-southwesterly winds of 35-45 knots in place
around 925mb through much of this time frame...there may also be some
periods of stronger downslope winds with gusts to 35-40 knots
possible along the Lake Erie shoreline. Otherwise we can expect
highs Friday to recover to the mid-upper 40s east of Lake Ontario to
the low-mid 50s elsewhere in spite of the showers...with evening
lows Friday night then ranging from the lower 40s across the North
Country to the upper 40s/lower 50s south of Lake Ontario...before
giving way to rising temps overnight as warm advection strengthens
again out ahead of the system`s approaching cold front.

On Saturday the surface low will pass by a bit to our northwest
while sweeping its trailing strong cold front across our area
between the morning and early afternoon hours. The very mild airmass
out ahead of the front will likely allow for high temperatures to
reach the mid 50s to mid 60s prior to the fropa...and would likely
allow for a line of at least some heavier showers and (though not
currently explicitly mentioned in the forecast) possibly even some
thunderstorms to mark the frontal passage...with these potentially
supporting some strong gusty winds in and of themselves given the 50-
60 knot flow that looks to be present not that far off the deck.
Following the frontal passage...strong cold advection should then
help to better mix down lingering strong winds from aloft for a
rough 3-6 hour period between the rest of Saturday and early
Saturday evening...with some potential for the stronger winds to
extend a bit further inland this time around given a more rapid
shift in wind direction from southwesterly to westerly. At this
point the medium range guidance continues to suggest the potential
for anywhere from a higher-end advisory to lower-end warning-type
wind event...with the previously noted gap between the GFS/GEM and
ECMWF solutions narrowing some with this cycle.

Otherwise...we can expect rapidly falling temperatures and
diminishing shower coverage in the wake of the frontal passage
Saturday afternoon and evening...which could allow for the lingering
pcpn to mix with or change to a little wet snow before coming to an
end by late Saturday night. By later Saturday night temps will
primarily range through the 20s...with winds also coming down
markedly as surface-based ridging builds into our region.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
In the extended portion of the forecast...Canadian surface high
pressure still looks to build overhead and provide us with a
quiet/dry and chillier than normal Sunday...with highs mainly in the
upper 30s and lower 40s. This ridge will then depart off to our east
Sunday night through early next week...with redeveloping warm air
advection on its backside then helping to send temps back up to
above normal levels for Monday and Tuesday. This being said...
precipitation potential remains more difficult to pin down for the
early part of next week with the medium range guidance packages
still showing significant differences on the evolution of the next
low pressure system(s) to affect our region...so for now have just
continued to indicate some broadbrush slight chance to lower-end
chance PoPs in the forecast.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Scattered light rain showers mixed with a bit of snow or graupel
will continue for a bit longer this afternoon south of Lake Ontario
as daytime heating bubbles up residual low level moisture. This
activity will wind down after 20z. MVFR/VFR CIGS will slowly break
up and clear out through this evening as high pressure slides east
across the Great Lakes.

High pressure over the region tonight will bring widespread VFR
conditions and light winds.

Outlook...

Wednesday...VFR early. Restrictions developing in the mid afternoon
through early evening in gusty rain and snow showers.
Thursday...Mainly VFR.
Friday...Restrictions likely in rain showers.
Saturday...Restrictions likely in rain showers. Strong winds possible.
Sunday...Mainly VFR.

&&

.MARINE...
High pressure centered over the Upper Great Lakes and Midwest will
build and slide east across the region through tonight. This will
promote generally light winds and minimal wave action.

Southwest winds increase ahead of an approaching cold front
Wednesday, before switching to northwest behind the front Wednesday
night. This period will likely require small craft headlines.

Winds lessen for a period before ramping back up Friday into the
weekend.

&&

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

&&

$$

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

NWS BUF Office Area Forecast Discussion