Area Forecast Discussion
Issued by NWS Buffalo, NY
FXUS61 KBUF 271858
Area Forecast Discussion
National Weather Service Buffalo NY
158 PM EST Mon Feb 27 2017
Weak high pressure will keep mainly dry weather across our region
through tonight. A warm front will then bring an increasing risk for
some showers on Tuesday...before more widespread showers and possible
thunderstorms develop later Tuesday night and Wednesday as low pressure
moves through the Great Lakes. Temperatures will remain well above
normal through Wednesday...before colder air returns late in the
.NEAR TERM /THROUGH TUESDAY/...
Surface-based ridging will prevail across the Lower Lakes Region
this afternoon...supporting continued dry weather. Skies will also
tend to be mostly sunny for much of the area...though there will be
a couple of exceptions. The first of these will lie across the North
Country...where a dying surface trough will continue to generate some
clouds through mid afternoon. The other will be across the Southern
Tier...where mid level clouds will gradually increase as warm air
advection increases ahead of a weak mid level wave over the Ohio
Valley. As for temps...ongoing low level warm advection will support
highs in the mid to upper 40s for most areas...along with a few lower
50s in the normally warmer spots of the Genesee Valley and Finger
Tonight the aforementioned mid level wave over the Ohio Valley will
quickly slide east and off the mid Atlantic coastline...while weak
low-mid level warm air advection continues across Pennsylvania and
New York. The weak warm advective regime will drive a south-north
increase in cloud cover across the region tonight...with perhaps just
enough moisture and lift available to generate a few sprinkles and/or
flurries across interior portions of the Southern Tier...Finger Lakes...
and North Country. Otherwise the night will be dry...with the increasing
cloud cover helping to keep temps from dropping below the lower to
mid 30s south of Lake Ontario...and the upper 20s across the North
On Tuesday expect a dry start to the day...before strengthening warm
air advection and an approaching warm frontal boundary bring about the
likelihood of a few light showers for during a portion of the afternoon.
Otherwise temperatures will continue to trend higher under the continued
warm advection...with our region seeing afternoon highs ranging from the
upper 40s and lower 50s across the North Country to the mid and upper 50s
south of Lake Ontario.
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Tuesday night into Wednesday, as secondary, stronger, wave of
low pressure will track along the baroclinic zone draped from
the central Plains to the lower Great Lakes. This will bring
added warm air advection, along with much stronger moisture
advection and synoptic lift. This will result in more widespread
showers Tuesday night in Wednesday, that will likely come in a
few rounds: 1/ on the nose of the best moisture advection
Tuesday night, then perhaps a pre-frontal trough Wednesday
morning and again with the strong cold frontal passage Wednesday
afternoon. Thunderstorms will also be possible, and while
overall instability will be marginal, the strongly forced and
high shear environment could result in a few strong storms
capable of producing bowing segments with damaging wind gusts.
In fact, SPC has included the area in a marginal risk for severe
weather on Wednesday, in the latest day 3 outlook. Will
continue to mention this in the HWO. Expect temperatures to
remain near steady then rise overnight Tuesday night, while
topping out in the upper 50s to mid 60s across the region
Rapid cold air advection in the wake of the surface front passage
late Wednesday may allow for a brief change over to some snow
showers before precipitation tapers off Wednesday evening.
Otherwise, strong synoptic wind gusts are also possible late
Wednesday the increasing cold air advection and subsidence in the
wake of the passing deepening low will help to get some stronger
gusts to surface. There remains some uncertainty with how strong
these winds would be, as the surface low may not really start to
strengthen until is pulling well away from the region, and this would
limit the strength of the winds aloft to mix to the surface.
However, it is possible a wind advisory may be needed for the
typical wind prone lake plains, and thus will continue to mention in
the HWO. Temperatures will sharply fall back into the upper 20s to
low 30s through Wednesday night returning our weather back to more
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Winter conditions will return for the end of week into the weekend
as a deep progressive trough brings a surge of colder air across the
northeast CONUS. Weak shortwaves may affect the region in the
developing northwest mid/upper level flow. Confidence is getting
higher that enough cold air will slide into the area for increasing
northwest/west-northwest flow lake effect snows from late Thursday
into Friday night as 850 mb temperatures drop to around -18C by
Friday night. A stronger Pacific shortwave and surface low moving
into the upper Great lakes will bring increasing warm air advection
later Saturday and Sunday with precipitation chances diminishing
along with moderating temperatures into the 40s by Sunday.
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
VFR conditions will prevail across the region this afternoon...with
most areas continuing to seeing a good deal of sunshine. This said...
mid level clouds will be more common across the North Country through
mid afternoon in association with a dying surface trough...while another
area of mid level clouds spreads into the Southern Tier.
Tonight a weak mid level wave will pass by to the south of the area...
with continued weak warm air advection bringing a south to north increase
in cloud cover...and perhaps a few sprinkles or flurries to interior
portions of the Southern Tier...Finger Lakes...and North Country. While
conditions should remain VFR in most areas...there could be enough low
level moisture to allow for a period of MVFR ceilings to develop across
the Southern Tier.
On Tuesday...expect mostly dry conditions to prevail during the morning...
before an approaching warm front brings a period of a few light showers
during the afternoon. Expect conditions to be largely VFR...with some
MVFR possible across far western New York later in the afternoon as low
level moisture increases.
Tuesday night...Deterioration to MVFR/IFR with more widespread showers
and possible thunderstorms developing.
Wednesday...MVFR/IFR in widespread showers and possible thunderstorms.
Thursday and Friday...Scattered snow showers with areas of MVFR.
Southwest winds will continue to diminish this afternoon as the pressure
gradient relaxes across the Lower Great Lakes. This should allow remaining
advisory-level winds and waves on Lake Ontario to finally fall below
advisory criteria by late this afternoon. Winds will then generally
remain light to modest tonight through most of Tuesday.
Stronger winds will then return Tuesday night and Wednesday as a deepening
area of low pressure moves across the Great Lakes...then will continue
through Wednesday night and Thursday as the low deepens further while
tracking across the Saint Lawrence Valley and Canadian Maritimes.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for