Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
246 am EDT Monday Mar 10 2014
a weak storm system will drop across Eastern Lake Ontario and bring
some light snowfall across the North County. Slightly warmer
temperatures will move in on Monday and Tuesday then another storm
system has the potential to bring some snow mid-week...followed by
another shot of cold air.
Near term /until 6 PM this evening/...
low level /surface to 800mb/ warm air advection is ongoing across
our region early this morning as observed on kbuf laps sounding and
mesoanalysis graphics. Viewing high level kbgm radar scans...as kbuf
and ktyx remain inoperable...along with surface observation show a band
of snow continuing to fall across the North County. This is
occurring as the low level warm advection interacts with enhanced
middle level moisture and thermal gradient with a wave of low pressure
translating southeast from the upper lakes. A blend of
NAM/sref/rgem/GFS quantitative precipitation forecast graphics suggest about 2 to 3 inches total
across Jefferson and Lewis counties this morning.
Across western New York and The Finger lakes some radar returns are
being picked up but the laps sounding is suggesting that drier air at
the low levels and strong winds just above the surface are keeping
the precipitation from reaching the ground. The weak warm advection...winds
and cloud cover will keep temperatures slowly rising overnight. Many
locations across wny are reporting middle to upper 30s thanks in part
to a downsloping component from the southwest flow. A 50 knot 850mb
jet will also keep some gusty winds around this morning but a
surface inversion will keep the highest winds from reaching the
ground. Wind gusts to 40 miles per hour look to be about the maximum.
On Monday...the temperature gradient aloft will sharpen as a well
aligned wind field aloft helps enhance a warm frontal boundary
across our region. There will not be any well defined areas of warm
air advection...but any ripple could spark a rain or snow shower
along the boundary. This sharpening boundary aloft will trap
moisture in the low layers...likely resulting in lingering clouds
for most of the day. Meanwhile...a southwesterly flow will bring in
warmer and fairly moist air...with a possibility of fog as dew
points rise into the middle 30s. Eventually...the low moisture should
start to mix out across western portions of the southern tier late
in the day...while clouds should persist elsewhere. Temperatures
should rise into the upper 30s to lower 40s...with forecast highs on
the lower side of available guidance due to the lingering cloud
cover. If low level moisture does mix out early...that would allow
temperatures to rise significantly more than forecast...but given
the light flow and fairly deep moisture expect that is a less likely
Short term /6 PM this evening through Wednesday night/...
as low pressure over central Quebec starts a weakening and filling
process...a slow moving cold front trailing this low will slow
further and stall across the Lake Ontario basin and southern
Ontario. This will form a col in the pressure pattern between high
pressure centers over western Ontario and the waters of the western
Atlantic...and regions of low pressure over Quebec and a stronger
developing system in the middle Mississippi Valley. Partial sunshine
through middle and high clouds and a neutral thermal advection pattern
will allow somewhat milder temperatures in the upper 30s to lower 40s for
most of the forecast area...even to the middle 40s closer to The Finger
The benign weather will not last long as the midwestern storm will
gather strength and move up the Ohio Valley Tuesday night and
Wednesday. A warm front will become established along or just south
of the New York/PA line with surface winds across New York state veering
to northwest then north as the region of low pressure passes
eastward across southern Pennsylvania. Expect a widespread steady
snow to develop late Tuesday night and intensify during Wednesday...
diminishing Wednesday evening as the backside of the middle/upper
deformation zone passes. A general consensus of GFS/ECMWF/gefs shows
western to central New York receiving the greatest amount of snow...but
whether that amount of snow will reach warning criteria is still in
question. Also...given the recent model variability of storm tracks
and placement of the heavier snow swath...will hold off a little
longer on a Winter Storm Watch until confidence is higher.
Gusty northerly winds will bring cold enough airmass to kick off
some lake snow showers overnight Wednesday night. Overnight lows
will plummet to the lower single numbers to below zero readings...
with temperatures closer to 10 above right along the Lake Ontario shore.
Long term /Thursday through Sunday/...
colder air will follow the storm with northerly winds across Lake
Ontario producing a broad area of lake effect snow showers on
Thursday. European model (ecmwf) and GFS show a rather narrow through with 850mb
temperatures falling to -20c but subsidence inversion and dry air down to
about 4kft will limit the vertical development of snow cells. Expect
scattered lake snow showers with some heavier but fast moving cells.
High temperatures on Thursday will struggle to get out of the teens for
most locations with lower 20s along the immediate Lakeshore areas
close to Lake Ontario.
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. Highs on Friday and
Saturday will be in the middle to upper 30s.
High pressure ridging in across the Great Lakes will bring an end to
any chance of precipitation and should offer a fair amount of sunshine.
This will offset the cold advection and keep highs in the middle to
Aviation /07z Monday through Friday/...
VFR flight conditions found across much of western and central New York
at 06z...though IFR ceilings/visible are in place across the North County
including kart as a weak surface wave continues bring snow north of
ksyr this morning. A 50 knot low level jet is bringing some gusty
winds as well this morning. Some low level wind shear is possible where these higher
winds struggle to mix to the surface. Toward daybreak across wny and
cny ceilings will lower to MVFR as the surface wave brings increased low
level moisture and scattered rain/snow showers south of Lake
Ontario. Warmer air and rising dewpoints under southwest winds will
bring some patchy fog later today which may bring IFR visible to some
Widespread MVFR ceilings will continue this evening as moisture lingers
beneath a low level inversion. Some patchy fog may also linger into
the evening. Another low level jet will cross western New York this
evening to the south of another weak surface low and bring
another period of gusty winds for western New York and another round
of showers across central New York through the North County.
tonight...MVFR. In ceilings and patchy fog.
Tuesday night and Wednesday...IFR. Snow.
Thursday...VFR/MVFR. A chance of snow showers.
southwest winds will continue this morning across western New York
as a low level jet crosses the lower lakes. Have continued with a
Small Craft Advisory for Western Lake Ontario where winds will be
strongest. After this...expect a modest southwesterly flow later today
through mid-week. A developing storm may bring Small Craft Advisory
to possibly gales on Wednesday...depending on its strength and track.
Marine...Small Craft Advisory until 5 am EDT early this morning for