Area Forecast Discussion
Issued by NWS Buffalo, NY
FXUS61 KBUF 261505
Area Forecast Discussion
National Weather Service Buffalo NY
1005 AM EST Sun Feb 26 2017
Lake effect snow east of the lakes will end today as a weak ridge of
high pressure builds into the area. Mainly dry weather will then
continue through Monday before a warm front brings a few rain
showers on Tuesday. An area of low pressure will then move through
the Great Lakes Wednesday with another period of rain and gusty
winds. Temperatures will warm to well above normal again by
Wednesday before winter cold returns late in the week.
.NEAR TERM /THROUGH TONIGHT/...
Late this morning, radar shows lake effect snow showers lifting
northward as the flow becomes more westerly. Mesoscale guidance,
including the RGEM show a brief consolation of the band
southeast of Lake Ontario centered on Northern Cayuga county.
This will be brief, with winds continuing to shift to the
southwest by this afternoon. Even so, a narrow band may produce
localized snowfall amounts of 2 to 4 inches through early
afternoon before lifting northward and weakening with lowering
equilibrium levels. This is supported by mesoscale guidance and
confirmed by upstream radar trends. Otherwise, lake effect snow
showers are disorganized, with a surface ridge forecast to build
in quickly from the west. Elsewhere, expect additional
accumulation today to be less than an inch.
Morning clouds should give way to some sunshine this afternoon
as low level moisture diminishes. Temperatures will be near
normal for late February, with mid 30s on the lake plains and
around 30 on the hills.
Tonight a weak warm front will move from southwest to northeast
across the area. Sparse low level moisture should keep most of the
area dry, with the warm front producing a brief period of mid level
cloud cover. Skies will then partially clear overnight in the wake
of the warm front, with the exception of the eastern Lake Ontario
region where more cloud cover will remain. Lows will occur early
this evening, with lower 30s on the lake plains and mid 20s across
interior areas. Temperatures will then begin to warm overnight under
weak warm advection and increasing winds.
It will become quite windy overnight as a 50+ knot low level jet
crosses the area. Expect gusts to reach 40-45 mph northeast of Lakes
Erie and Ontario with channeling down the lakes, and 30-35 mph
farther inland. Winds aloft could support advisory criteria wind
gusts northeast of the lakes, but weak warm advection and poor low
level lapse rates will likely inhibit full mixing.
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
Monday and Monday night will feature mainly tranquil weather and
will mark the beginning of a warming trend through mid-week. On
Monday morning, a shortwave exiting into Quebec will push a very
weak cold front through the North Country. Moisture and forcing will
be very limited, but with some orographic lift, have included a low
chance PoP over the Tug Hill and western Adirondacks. Otherwise, a
secondary weak shortwave passing to our south later in the day
Monday may bring a few isolated showers to the southern Tier.
Otherwise, expect a mainly dry day with some cloud cover and
temperatures recovering into the low to mid 40s across the region
with the help of weak warm air advection.
The moderating trend will continue Tuesday into Wednesday, but this
will also bring rain and a chance of thunderstorms back to the
region for mid-week. Broad troughing carving out across the western
CONUS will help build warmth across the eastern CONUS and sharpening
the temperature gradient along a line from the central plains to the
Great Lakes. A surface low will develop and track just west of the
forecast area, strengthening with time as it tracks into southern
Quebec / northern New England by Thursday morning. Warm advection,
along with a shortwave along the frontal boundary ahead of the main
low, will bring some shower chances to the region as early as
Tuesday, with a slight chance of some thunder. Temperatures will
also rise back into the 50s across western NY and the upper 40s
across the North Country. Continued warm advection Tuesday night
with the surface low deepening just to our west should place us in
the warm sector Tuesday night into Wednesday morning. Thus have
temperatures maintaining or even warming some overnight into
Wednesday. Temperatures could top out in the low 60s for some on
Wednesday. However, shower and thunderstorm chances will increase
across the region as well as the cold front will cross the area from
west to east Wednesday into Wednesday night. The strongly forced low
cape / high shear environment could even produce some stronger
thunderstorms with gusty winds. There remain some differences
between the GFS/EC with regard to surface low strength/track, but
there remains some potential a change over to snow from west to east
Wednesday night before precipitation ends. Also depending on the
track/strength of the low, strong winds are possible in the wake of
the cold frontal passage.
.LONG TERM /THURSDAY THROUGH SATURDAY/...
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. 850 mb temperatures will fall into the negative
teens celsius later Thursday and Friday, which will keep daytime
highs below freezing in many locations Thursday into Saturday.
Nighttime lows will fall into the 20s, and even teens to single
digits by Friday night as 850 mb temps could fall to -20C or colder.
Lake effect snow chances will also increase with this colder air
spilling across the largely ice-free lower Great Lakes. The best
chance for accumulating lake effect snows appears to come Thursday
night into Friday for favored west-northwest flow locations.
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
Conditions will vary through mid-afternoon with mainly VFR
conditions but areas of IFR or lower in lake effect snow
showers. For the most part, lake effect snow showers will not be
at TAF sites, but these may impact BUF/IAG/ROC/JHW at times.
VFR will then prevail later this afternoon and tonight. A weak warm
front will cross the area from west to east tonight with a period of
mid level clouds. Winds will remain on the stronger side, with gusts
to around 25 knots today. Winds will increase again tonight after a
brief lull early this evening, with gusts to 35 knots northeast of
the lakes overnight.
Monday...Mainly VFR, possible MVFR with chance of -SHRA/-SHSN east
of Lake Ontario.
Tuesday...VFR/MVFR with a chance of showers.
Wednesday...MVFR/IFR with periods of rain.
Thursday...Mainly VFR. A chance of snow showers.
A strong pressure gradient between high pressure centered over the
southeast states and low pressure over the Canadian Maritimes will
maintain moderate to strong winds on the Lower Great Lakes through
Monday morning with higher end Small Craft Advisory conditions.
Winds will diminish Monday afternoon as a ridge of high pressure
briefly builds into the Lower Great Lakes.
Stronger winds will return Wednesday night and Thursday in the wake
of a deepening storm over Quebec.
flood warnings remain in effect for the Eastern Lake Ontario
region for the Black River from a combination of rapid
snowmelt and heavy rainfall from Saturday. The Black River at
Boonville will continue to rise today and crest this afternoon
in minor flood before falling on Monday. The lower reaches of
the Black River at Watertown and in northern Lewis County
responds much more slowly. The river will continue to rise
through at least Tuesday reaching at least minor flood stage,
with moderate flood stage a possibility. The river will not
likely drop below flood stage until late week.
Elsewhere across the eastern Lake Ontario region, a flood watch
remains in effect today. Other smaller streams and rivers which
drain the Tug Hill and western Adirondacks will continue to run
high today and may result in minor flooding.
NY...Flood Watch until 7 PM EST this evening for NYZ006>008.
MARINE...Small Craft Advisory until 1 PM EST Monday for LEZ040-041.
Small Craft Advisory until 7 AM EST Monday for LEZ020.
Small Craft Advisory until 4 PM EST Monday for
Small Craft Advisory until 1 PM EST Monday for LOZ042.