Area Forecast Discussion Issued by NWS Buffalo, NY
000
FXUS61 KBUF 131928
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
328 PM EDT Wed Mar 13 2024
.SYNOPSIS...
It will be another warm and dry day across the eastern Great Lakes
region today. A low pressure system will track along a front just
south of New York State on Thursday. This will bring increasing
chances for rain showers by Thursday night and into Friday. Dry
weather briefly returns Saturday as high pressure passes by to the
south of the region.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
Satellite imagery shows mostly sunny skies across western and north
central NY this afternoon. Warm conditions will continue today with
temperatures mainly in the 60s. Locations in the Genesee Valley such
as Rochester and Dansville may reach 70 this afternoon. A southwest
wind will keep locations upstream from Lake Erie and Lake Ontario
cooler, with temperatures remaining in the 50s.
A stationary front lies just south of the New York/Pennsylvania line
tonight. Lack of moisture and a building ridge will maintain dry
weather across the region with low temperatures in the upper 30s to
low 40s tonight. A shortwave trough will break away from a cut-off
low over the four corners area tonight. Surface low pressure over
the southern Plains will move northeast and along the nearby
stationary front by Thursday night.
Initially, dry and calm weather will continue into Thursday as the
stationary front moves north into western NY. A surge of warmer air
will move into the region, however high pressure to the north will
hold the warmer air aloft north of the boundary. We will likely see
a dichotomy in temperatures across the region Thursday with highs
reaching the upper 60s to low 70s across the western Southern Tier
to the low 50s across the Saint Lawrence Valley to the southern
shore of Lake Ontario. Surface low pressure will reach Lake Erie by
Thursday evening with increasing mid-level convergence and strong
warm air advection across the region. PWATS increase to an inch
across the region and rain showers will enter western NY as early as
3PM Thursday. Rain showers will become widespread by Thursday
evening with periods of moderate showers along and north of the
frontal boundary Thursday night. There is a slight chance for
thunderstorms across southwest NY, mainly the western Southern Tier
Thursday night. This region is on the fringe of weak elevated
instability with better conditions for thunderstorms across the Ohio
Valley. Forecast rainfall amounts will average 0.25-0.50 inches with
less than 0.25 inches across the Finger Lakes region. Higher amounts
are possible in thunderstorms.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Zonal flow aloft Friday will give way to a subtle shortwave Friday
night before the next quick paced shortwave dives southeast across
the Great Lakes Saturday. Meanwhile down at the surface, a surface
low and trailing cold front will be in the midst of exiting east
into New England Friday morning, which will support the lingering
rain showers to exit from west to east.
Brief upper level ridging Friday night through Saturday ahead of the
next fast moving shortwave trough, will support a surface ridge to
slide across New York State and result in a period of dry weather
late Friday night through Saturday.
Temperatures to close out the week and start of the weekend will be
cooler than earlier in the week, though remain slightly above
normal. Highs Friday and Saturday will range in the upper 40s to low
50s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A significant pattern shift to much more winter-like conditions will
take place during this period as a deep upper level trough becomes
established across the eastern third of the CONUS.
As we open the period, a vigorous Clipper system will be diving east-
southeast through northwestern Ontario, then slows down as it turns
more easterly while moving south of James Bay, eventually locating
itself over south-central Quebec by late Sunday. An initial cold
front trailing the system will push east across the area Saturday
night bringing a round of mainly rain showers to the region, with
some wet snow flakes possibly mixing in across the higher terrain
depending on how fast the colder air moves in. Wraparound moisture
will linger through the day Sunday with precipitation mainly in the
form of plain rain showers across the area, most numerous across
upslope areas. Some wet flakes will continue to be possible across
higher terrain, although near-surface temps will be marginal even
over the higher elevations. Daytime highs Sunday will be mainly 40s,
with some upper 30s across the higher terrain.
Synoptic moisture remains in place Sunday night as airmass off
the deck continues to slowly cool, with 850Ts getting down
around -8C to -10C late. This will allow for scattered lake
enhanced and eventually westerly flow lake effect snow showers
to develop east of the Lakes. A secondary cold front will move
across the area on Monday bringing the likelihood for a period
widespread snow showers for most areas. Winds veer WNW/NW behind
the boundary with widespread snow shower activity tapering off
to more upslope/lake effect dominant for Monday night into
Tuesday as 850Ts bottom out around -12C. Some accumulating
upslope/lake effect snows will be possible during this
timeframe, although mid March sun angle will at least somewhat
disrupt lake effect and hinder accumulations during the daylight
hours. Ground temps will take a bit to cool down as well.
Temperatures will be running some 5-10 degrees below average (15
deg below in some cases), with daytime highs possibly not
reaching the freezing mark across the higher terrain Monday and
Tuesday.
High pressure will then try to ridge in across the area toward mid
week. Drier air and subsidence associated with this feature will
help taper off the more persistent lake effect/upslope snows,
however it will remain cold enough aloft that a few lingering lake
effect snow showers will remain possible, especially downwind of the
Lake Ontario. Daytime highs will remain below average through
Wednesday.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected across the TAF sites through Thursday
morning.
A weakening low level jet will produce gusty winds around 25-30 kts
across parts of western NY early this afternoon. Winds will diminish
through the afternoon and become light overnight. A stationary front
south of the New York State line will move north Thursday. A
southerly flow will increase aloft which may cause low level wind
shear across western NY Thursday afternoon. Rain showers will hold
off until after 3/14 18z.
Outlook...
Thursday night...MVFR/IFR with showers likely and a slight chance of
a thunderstorm across southern New York.
Friday...MVFR/VFR with a chance of showers.
Saturday...Mainly VFR.
Sunday...VFR/MVFR with a chance of showers.
Monday...MVFR/IFR possible with snow showers.
&&
.MARINE...
A stationary front will remain south of New York State through
tonight. Southwest winds will remain elevated on the waters this
afternoon before diminishing with minimal wave action tonight.
The stationary front will move north and stall near Lake Erie and
Lake Ontario Thursday. Low pressure will track along the front
bringing widespread rain and an increase in winds on the waters.
There is a chance small craft advisory levels may be reached
Thursday night.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...AR/HSK
NEAR TERM...HSK
SHORT TERM...EAJ
LONG TERM...JM
AVIATION...HSK
MARINE...HSK