Forecast Discussion

Forecast Discussion for BUF NWS Office
000
FXUS61 KBUF 180251
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
951 PM EST Sat Nov 17 2018

.SYNOPSIS...
A weak cold front will drop across the region this evening with some
light snow showers, but otherwise dry conditions. Weak low pressure
will pass to our south on Sunday bringing some light snow to the
Southern Tier. There will be some light snow showers during the
first half of next week, followed by high pressure and cold and
dry weather for Thanksgiving.

&&

.NEAR TERM /THROUGH SUNDAY/...
A cold front lies across New England, with the tail end back across
the Finger Lakes and WNY. Moisture continues to deplete across our
region as a large area of high pressure and its associated dry
airmass pushes eastward from the Plains. A few light snow showers
may fall through the late evening hours near the cold front, and
southeast of the lakes on a weak lake effect response deeper into
the night, otherwise a cloudy sky will remain through much of the
night. Additional snow through the remainder of the night will be
little to none, though a half to one inch of snow is possible SE of
Lake Ontario in any narrow bands of LES that develop.

Winds will shift to the southeast Sunday morning so any lingering
lake effect snow will move out over the lake. Low temperatures
tonight will be around 20 east of Lake Ontario and mid to upper 20s
across WNY.

On Sunday a shortwave embedded in a vigourous upper level flow will
move across the region. There will be a sharp mid-level thermal
gradient across the area, with this shortwave resulting in a period
of warm air advection and favorable jet dynamics. Nearly all model
guidance shows measurable precipitation across southern areas, with
little if any precipitation north of I-90 from Buffalo to Syracuse.
However model agreement and synoptic scale lift supports categorical
PoPs across the Western Southern Tier even if snow accumulation will
only be around an inch. Temperatures will remain below normal on
Sunday with highs in the lower to mid 30s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
A 120kt upper level jet will be moving across the Northeast while
surface low pressure tracks along a stalled front south of Western
NY Sunday night. Dry westerly flow will be increasing across the
eastern Great Lakes and light snow will be departing the Western
Southern Tier through Sunday evening. Cold, southwest flow will lead
to the generation of lake effect showers northeast of the lakes
Sunday evening. Due to the incoming dry airmass, snow showers will
be scattered and light. Temperatures will fall into the mid to upper
20`s Sunday night.

The mean flow will slowly become westerly by Monday morning and snow
showers will move east of the lakes impacting the Southtowns and
Western Southern Tier and east of Lake Ontario. Synoptic moisture
will increase from the north as a shortwave trough approaches Lake
Ontario. This will likely keep snow showers east of Lake Ontario
with enhancement on the Tug Hill into Monday evening. With this
being said, subsidence and mid-level dry air will still keep snow
showers scattered and lackluster east of Lake Ontario. Snow showers
will end east of Lake Erie by Monday afternoon. Minor accumulations
of up to an inch are expected east of Lake Ontario, mainly on the
Tug Hill. Areas outside of the lakes will remain dry Monday.
Temperatures will reach the mid to upper 30`s.

A large scale mid-level trough will remain overhead Monday night
into Tuesday night. Surface low pressure will track across the
northern Great Lakes reaching Lake Ontario by Tuesday morning. A
cold front will move across the eastern Great Lakes and snow showers
will track across western and north-central NY. Lake enhancement
will produce minor accumulations northeast-east of the lakes by
Tuesday afternoon. As flow becomes northwest behind the front, snow
showers will persist southeast of the lakes where minor
accumulations are possible into Tuesday night. Cold with
temperatures falling into the low 20s to teens east of Lake Ontario
Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Second clipper shortwave and associated cold front expected to
cross the area Wednesday. At this stage, only looking at some
nuisance snow showers and limited lake effect potential. Even
though the potential for accumulating snows look limited, those
planning to travel are strongly encouraged to stay up to date
on the forecast as it doesn`t take much snow to cause travel
issues.

Secondary thermal trough will filter in for Thursday on the
front side of an approaching area of high pressure and will
bring 850 mb temperatures back down below -15C, resulting in a
very chilly Thanksgiving day with high temperatures capping in
the 20s and wind chills in the teens or colder at times.

The much anticipated warm-up is still on track, but a bit later
than in previous forecasts. Warmer temperatures will arrive
Friday and Saturday with most locations see highs in the mid to
upper 30s Friday, and in the 40s with 50 degrees not out of
question for Saturday. Precipitation chances will increase
Saturday as a rather deep but short-wavelength trough swings
through the Great lakes.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Flight conditions are generally MVFR/VFR across the region this
evening, and these conditions will prevail through the next 12
hours. Some light snow showers and flurries will fly through the
next 6 hours, and may bring reduced visibilities briefly in an
otherwise mainly VFR flight visibility environment.

A storm system will track by just to our south tomorrow, and this
feature will bring a brief burst of synoptic snow across southern
zones, including the KJHW terminal. Expect IFR or lower flight
conditions within snow.

Outlook...

Monday through Wednesday...VFR/MVFR. Periodic snow showers.
Thursday...VFR.

&&

.MARINE...
Westerly winds will gradually diminish through this evening as
surface high pressure builds toward the region. Small craft
advisories will continue for the central and eastern waters of Lake
Ontario this evening. A few weak systems may result in a brief
increase in winds Monday through Wednesday, but for the most part
the first half of the week should be headline free. High pressure
will build across the lower Great Lakes Wednesday night and Thursday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 1 AM EST Sunday for LOZ043>045.

&&

$$

SYNOPSIS...Apffel
NEAR TERM...Apffel/Thomas
SHORT TERM...HSK
LONG TERM...TMA
AVIATION...Thomas
MARINE...Apffel/Thomas

NWS BUF Office Area Forecast Discussion