Scientific Forecaster Discussion
fxus61 kbgm 061548
Area forecast discussion
National Weather Service Binghamton New York
1048 am EST Tue Dec 6 2016
weak high pressure will sit over the area through the early
afternoon resulting in a brief period of quiet weather. The next
storm system to impact the region will roll into the area this
afternoon bringing rain and snow showers to central New York and
northeast Pennsylvania. High pressure will build back into the
region on Wednesday producing dry and seasonable weather.
Near term /through Wednesday/...
11 am update...
other than cosmetic temperature and sky cover tweaks, no
significant changes to the forecast at this time.
Thicker clouds continue to stream into the forecast area at
midday, and these clouds will lower and thicken further this
afternoon. Highs are still expected to reach the upper 30s-lower
Steadier precipitation has reached the far southern tier of PA as
of midday, and it will make further progress to the north and east
as the afternoon wears on. We expect a light rain/snow mix to
develop over northeast PA and portions of ny's southern tier,
mainly in the 5-7 PM time frame.
We'll take a closer look at tonight's system with the next
forecast update early this afternoon.
Previous discussion... 400 am EST update...
some stratus is present this morning over central New York as a low-lvl
inversion continues to trap lingering moisture from yesterday's
lake effect(le) showers. There are a couple of sprinkles
lingering, the atmosphere is too warm for ice crystals to be
introduced to the clouds, thus what will continue to linger this
morning will fall in the form as rain.
This morning and afternoon will be fairly quiet as weak high
pressure will sit over the region combined with anti-cyclonic flow
aloft. This will be short lives as high pressure will drift to
the east this afternoon and the next system to impact the area
will start to move into the region.
Precip should start to push into nepa after 18z and spread north and east
into central New York by 00z. Precip type with this system will be
rain/rain & snow/snow. Precip type will be highly dependent on
elevation and sfc temp. This snow is expected to be a wet snow
with snowfall amounts ranging from a trace to up to 3 inches (with
the highest accumulations expected within the higher terrain). The
best chance for widespread precip across the region will be
between 7pm tues and 7am Wed. As temps decrease overnight(into
Wed morning) expect precip type to become more dominant snow, thus
expect during this duration to see the greatest accumulations. We
will closely monitor the event as it evolves, and if snowfall
amounts change and are expected to increase, we may consider
issuing an advisory.
Similar to the last system, expect this system to move out quickly
and the majority of the precip to be out of our area by 15z Wed, and
all chances for precip should end by 18z.
Temps will be in the lower 40s as this system first pushes in and
are expected to only fall into the low to mid 30s Tuesday night.
Temps are expected to quickly rise Wed morning into the uppr 30s.
Short term /Wednesday night through Thursday night/...
400 am EST update...
Wednesday night...southwest flow both at the surface and aloft
combined with surface high pressure in the mid Atlantic region will
make for a dry period. Overnight lows will range from the middle
20s to around 30.
Thursday...upper level trough moves into central New York by late
day. Initial surface trough crosses the region during the afternoon
bringing scattered snow showers to much of the region. By late day
flow becomes favorable for more significant lake effect snow to drop
into northern Oneida County. Will continue with likely pops here and
high chance for the rest of central New York with just low chance or
slight chance for northeast Pennsylvania. Snowfall for much of
central New York will be an inch or less with up to three inches in
northern Oneida County. Highs will range in the lower to middle 30s.
Thursday night...the temperature drops to around -10c while the low
level flow gradually veers. Model soundings show a fairly
significant moisture depth indicating lift in the dendritic snow
growth region. The GFS is faster with the secondary trough than the
NAM. The NAM would keep much of the significant lake effect snow
under a 285/290 flow through 12z Friday while the GFS indicates a
more northwest flow after 06z. For now will keep categorical pops
over much of Oneida, Onondaga and Madison counties. Several inches
of snowfall looks likely here with winter weather flags possible by
Long term /Friday through Monday/...
400 am EST update...
upper level trough remains over the northeast through the first part
of the weekend with lake effect snow continuing through Friday
night. Temperature at 850mb drops to -12/-14c both Friday into
Friday night so significant lake effect snow is possible through
this period southeast of Lake Ontario. By Saturday weakening flow
and decreasing moisture will result in the activity gradually
diminishing while it lifts back north. Temperatures Friday through
Saturday night will run 5 to 10 degrees below normal.
For the remainder of the extended period the upper level flow across
the United States becomes more zonal. A couple of systems will move
into the western Great Lakes and through eastern Canada. This will
bring a chance for light snow through the period which could mix
with rain on Monday.
Aviation /16z Tuesday through Saturday/...
MVFR strato-cu clouds will continue to linger this morning over
ksyr and krme, these are expected to lift to VFR over the next
couple of hours. Kith, kelm, kbgm, and kavp are expected to
remain mostly clear and VFR through 21z. Winds will remain light
and easterly around 5-9 knots through 00z.
The next storm system will start to push into the area from the
SW around 18z. This system will bring fuel alternate ceilings,
along with embedded IFR. Precip will be a mix of -rasn and -sn.
Showers that become primary snow will have IFR visbys. Showers are
expected to continue through the night and produce 1 to 2 inches
of snow across the area. Winds will remain east/southeast around 5-10 knots
through 12z Tuesday.
Wednesday-Thursday...possible restrictions in lower ceilings and
scattered rain/snow showers.
Friday-Saturday...occasional lake-effect snow showers, with
associated restrictions, mainly krme/ksyr/kith/kbgm.