Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
137 PM EST Friday Dec 13 2013
lake effect snow will taper off later today as a storm approaches
the area from the south. This system will spread snow across the
area on Saturday...with the chance for some ice over parts of
Near term /until 6 PM this evening/...
12 PM update...les band has now been stripped off the long axis of
Lake Ontario as winds are now northerly. Allowed warning for northern
Oneida County to expire will continue with advection until middle afternoon
for areas southeast of lake.
1000 am update...les band east of Lake Ontario now making good
progress south as surface trough drops through the lake region. Local
arw handling the current orientation well and expect the bulk of
activity to be south of northern Oneida County around midday. Current
warning timing here looks good. Activity is now dropping south
into the advisory area. Band will weaken as it drops south due to
shorter fetch and gradually lowering inversion. Lake effect snow
showers will continue in the advection area until middle afternoon then
weaken. Just minor adjustments to current forecast.
tricky les forecast as the short term models are in poor agreement.
Wrfarw shows the band dropping southward into the daylight hers before
dissipating midday. NAM shows the band pretty much weakening in
place with only a slight southward drift. Crnts show the surface flow over
western New York becoming southwesterly making ME wonder if the band will ever make it
into the warning/advisory area. At the very least...incrsd ll
shear will weken the system. In any case...will leave the flags in
place for now but may be looking a modifying the flags early on.
Short term /6 PM this evening through Monday night/...
only a brief break in the action ahead of the next system. Overruning
precipitation develops late Friday night and early Sat under the rr of the upper jet.
Overall the upward vertical motion is moderate at best and
moisture is not exactly deep as the initial source region is the
upper plains. This shd result in light snows for the initial hours of the
Later Sat...deeper mositure from the Gulf arrives as the southern branch
system develops a surface low moving nwrd in the Tennessee Valley. System has double surface
lows early on with a low over Ohio while a coastal low deepens over eastern
NC. Lows consolidate around 06z sun over coastal New Jersey and begin to deepen
more rapidly. Good deep Ely flow develops late in the game and a period
of heavier snow seems likely late Sat night before the snow tapers
off Sun morning. Even so...best uvm is not exactly well aligned with
the best dendritic growth area for much of the storm. Also...
system remains as an open WV at the upper levels so is lacking a good
chance for deformation bands developing late in the event.
Even the normally robust NAM quantitative precipitation forecast forecasts are at high end advisory
levels for the storm ldg ME to think that snowfall amts will be below
warning criteria. Best chance for higher amts appear to be over the
western cats and perhaps xttrm nepa. Further south...there/S still the
risk of some ice pellets over the Poconos and Scranton metropolitan area.
Freezing rain seems like a more remote chance with the narrow above freezing
layer and very cold surface air.
Kind of hemmed in by watches so went with a watch for the area as
well...but most likely looking at a high end advisory.
Long term /Tuesday through Thursday/...
115 PM update...
with a snow event tomorrow I went with wpc guidance for the long
term period with a few minor tweaks. Overall a fairly quiet
pattern with no huge storms. We will see a series of weak
waves...one coming Monday night into Tuesday and again Tuesday
night into Wednesday...which will keep snow showers around. In
addition some periods of lake effect are possible. Toward
Thursday heights will rise and drier weather is expected. Although
beyond our current extended...both the GFS and Euro point to our
next system being an inland runner with much warmer air and rain
by the end of next week.
Aviation /18z Friday through Wednesday/...
115 PM update...
Two periods of concern for the tafs. The first will be through
early evening with ongoing lake snows...then a break...with a more
widespread snow developing during the day Saturday.
For now IFR visibilities will remain possible at ksyr/kith and kbgm
through 21z in lake effect snow. Outside of these areas VFR to
MVFR ceilings are likely through early evening with a few flurries or
a brief snow shower. After early tonight most terminals will go to
VFR with lake influences not being an issue anymore.
Toward daybreak Saturday snow will spread from southwest to
northeast across the terminals. Once the snow arrives IFR visibilities
will be likely through the rest of the day with low end MVFR ceilings
to perhaps some IFR especially on the elevated sites. Arrival time
looks to be between 12z and 15z southern terminals after 17z up
Sat night/sun...restrictions likely region-wide in snow as storm system
moves through the area...with each terminal experiencing IFR or
worse at times. Some improvement toward Sunday afternoon.
Sun ngt/Mon/Tue/Wed...restrictions possible from lake effect snow showers
PA...Winter Storm Watch from Saturday morning through Sunday
morning for paz038>040-043-044-047-048-072.
New York...Winter Storm Watch from Saturday morning through Sunday
morning for nyz009-015>018-022>025-036-037-044>046-
Lake effect Snow Advisory until 3 PM EST this afternoon for