Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
450 am EDT sun Mar 9 2014
lingering lake effect snow showers will taper off today as high
pressure builds over New York. Tonight a weak storm system will
cross Eastern Lake Ontario and bring some light snowfall across the
North County. Temperatures will warm a bit above normal early in the
new week then another storm system has the potential to bring some
snow mid-week...followed by another shot of cold air.
Near term /through tonight/...
surface high pressure is ridged from the Central Plains northeast to
the Great Lakes this morning. Northwest winds shifting around the
northern edge of this ridge are crossing Lake Ontario with a weak lake
response observed on radar. Light snow showers and scattered
flurries are showing up southeast of lakes Erie and Ontario where a
few tenths of an inch of snow may accumulate. In addition to the
snow...infrared satellite is showing low stratus southeast of the
lakes which is retreating to the southeast under a drier
Through the daylight hours we will see the surface ridging expand to
the east across the lower lakes with winds backing to the southwest.
This will allow the majority of the forecast area to see a good deal
of sunshine through much of the day except southeast of Lake Ontario
where some lake effect clouds and snow showers will linger through
the morning. The surface ridging will squash out the lake effect
snow showers by the early afternoon. Temperatures will run a little
cooler than what we saw on Saturday. Highs look to be capped in the
upper 20s to around 30 except across the Tug Hill with low to middle
A subtle shortwave and surface low found over Manitoba this morning
will shift southeast today glancing the northern edge of the upper
lakes then crossing the eastern end of Lake Ontario tonight. This
system will bring some snow showers overnight focused east of Lake
Ontario to the north of Oswego. Additional upsloping on the tug
looks to allow a general 2-4 inches of snow from the city of Oswego
northward. The track of this system will keep a dry forecast across
western New York but winds will become breezy overnight as the
surface pressure gradient tightens. Temperatures will remain steady
or slowly rise overnight under a continued southerly flow.
Short term /Monday through Tuesday night/...
Monday and Monday night a warm front will push east across the
region supported by a series of middle level shortwaves...each of which
will enhance large scale ascent and low level flow across the warm
frontal boundary. The first of these waves will be exiting the north
country during the morning...with light snow tapering off during the
morning as lift weakens and deep layer moisture consolidates farther
west across western New York. The next middle level shortwave and a stronger
push of low level warm advection will move across the north country
late Monday afternoon and evening...with another period of light
snow. By this time the boundary layer may be warm enough to allow
some rain to mix in...at least across lower elevations. There may be
some minor snow accumulations across the north country from both
Outside of the north country precipitation chances will be a little lower
and less organized...with mainly scattered rain and snow showers
Monday and Monday night. Snow will be predominant Monday morning and
again later Monday night when temperatures aloft and at the surface
are at their coolest. Rain will dominate Monday afternoon as a brief
push of warmer air moves into the region from the Ohio Valley. This
will allow temperatures to push into the lower to middle 40s from the
Genesee Valley westward...with middle to upper 30s across the north
country. Precipitation amounts will be very light...less than a tenth of an
inch total in most locations outside of the north country.
By Tuesday the surface low and middle level support will shift into the
Canadian Maritimes...leaving little in the way of forcing across our
region. Expect most areas to be mainly dry although there may still
be a good amount of cloud cover. It will remain mild with highs in
the lower to middle 40s in most areas and upper 30s across the north
Tuesday evening will start off dry...but that will likely change
overnight as a lead shortwave and increasing frontogenesis move
across the lower lakes ahead of a significant system for midweek.
This may spread some light snow into the area after midnight.
Long term /Wednesday through Saturday/...
all eyes will be on the potential significant system for the middle
of the week. Latest 00z European model (ecmwf) and GFS are starting to convergence on
a more similar solution...although there remains some notable timing
and track differences. The European model (ecmwf) remains on the slower and more
amplified edge of the ensemble envelope. The Canadian Gem remains
the weakest and farthest south with this system...although it has
been trending towards the other model guidance after being an
outlier yesterday. Gefs ensemble members all show a significant
system...but still have a decent amount of spread in timing...
track...and intensity suggesting there is still some uncertainty
with the outcome of this system.
Using a potential vorticity analysis on the 1.5 pvu surface near the
tropopause...we can trace back the energy responsible for this
system. This analysis yields a very complex pattern evolution...with
at least 3 separate potential vorticity anomalies moving out of the
Gulf of Alaska and one from far northern Canada. All of these
features eventually come together and aid in developing the system
in the east. With such a complex pattern evolution...one should take
current model runs with a degree of skepticism despite the
relatively good agreement between the GFS and European model (ecmwf).
Taking a model consensus between the GFS...ECMWF...and gefs
solutions it appears the chances for accumulating snow continue to
increase for Wednesday and Wednesday night. The mean surface low
track in this model blend would take a deepening low from the lower
Ohio Valley early Wednesday morning to just south of Long Island by
Wednesday evening before pushing towards Nova Scotia by Thursday
morning. Such a track is quite favorable for significant
accumulating snow across our region...but with the caveat of
inherent uncertainty at this time range. We will continue to outline
this potential in the severe weather potential statement.
Behind this system a middle level trough will rapidly sharpen as the
northern and southern streams fully phase...and the pattern also
amplifies upstream. This will dump another strong shot of cold air
into the Great Lakes and northeast with temperatures plummeting to
well below average again Wednesday night and Thursday with some
limited lake effect snow showers south and southeast of Lake Ontario
in the wake of the strong system.
The cold will be short lived as the trough remains progressive and
quickly moves out of the area. Expect temperatures to recover to
near average again by Friday. The next chance of light snow will
arrive later Friday night and Saturday as a weaker middle level trough
digs into the Great Lakes and northeast.
Aviation /09z Sunday through Thursday/...
high pressure will build across New York today with generally VFR
conditions. Across the southern tier...low stratus is bringing MVFR
ceilings but satellite loops show these clouds are quickly eroding and
clear skies are filling in. Tonight a weak storm system will cross
Eastern Lake Ontario with some light snow and IFR visible developing.
This IFR visible will be possible across the kart terminal in light snow
Monday...MVFR/VFR with a chance of rain/snow showers. IFR across the
north country with snow showers likely.
Tuesday and Wednesday...MVFR/IFR. Snow likely.
Thursday...VFR/MVFR. A chance of snow showers.
a weak ridge of high pressure will build across the lower lakes
through today before a warm front shift across the area tonight.
Northwest winds this morning will become southwest and increase
overnight. No Small Craft Advisory conditions expected.