Scientific Forecaster Discussion
fxus61 kbgm 161155
Area forecast discussion
National Weather Service Binghamton New York
655 am EST Mon Dec 16 2019
a period of light snow will move through northeast PA this
morning brining minor coatings. A more substantial low pressure
system will then bring snow and a wintry mix to the area this
evening into Tuesday as it slides through the mid-Atlantic
region. Then, turning much colder with numerous snow showers and
possible squalls midweek as an Arctic cold front moves through.
Near term /through Tuesday/...
630 am update...
Made minor adjustments to pops, quantitative precipitation forecast and precipitation types for
the rest of today and tonight based on the latest guidance.
Latest trends are a little colder aloft, with growing concern
for a burst of moderate to even heavy snow across NE PA and into
the southern Catskills late this evening into tonight...snowfall
rates could easily reach 1 inch per hour in this region for a
time. Bumped up snowfall totals slightly in this area.
Otherwise, the near term forecast remains on track.
400 am update...
Confidence increasing that an impactful winter storm will bring
snow and/or a wintry mix to the entire area this evening through
Tuesday. Winter weather advisories have been issued for almost
the entire County Warning Area (except northern oneida) to account for this
expected winter weather. The morning commute will likely be
impacted, with possible snow covered and icy roads Tuesday
A Few Lake effect flurries and light snow showers will clip
northern Oneida County through daybreak. Otherwise, latest radar
trends and observations show another area of light snow
currently across west-central PA. Consensus of the near term
guidance (including the hrrr) if for some light snow or flurries
to overspread much of our NE PA counties between 7-10 am this
morning...with the steadier light snow mainly along and south of
I-84, and especially down toward I-80. This quick round of
light warm air advection snow quickly diminishes by midday.
Could see a light dusting, to perhaps half an inch in this area.
The rest of the forecast area will see partly to mostly cloudy
skies, but dry weather through the daytime hours. Light south or
southwest winds under 10 mph. High temperatures should reach
30-35 this afternoon for most locations.
Tonight: the next, more impactful wave of low pressure and warm
air advection precipitation then quickly overspreads the area
from south to north later this evening and overnight. Good jet
support (right entrance region of 150 kt at 300mb) strong lift
and some mid level frontogenesis banding should allow for a
burst of moderate snow. Current timing brings the steady snow
across NE PA by late evening, reaching the twin tiers around or
just after midnight. Finally reaching the US-20 corridor during
the predawn early morning hours Tuesday, then the New York thruway by
daybreak. Snow bands within the broader area of light snow could
produce rates around 1"/hr at times. The snow will begin to mix
with sleet and freezing rain after midnight across NE PA.
Surface temperatures hover in the mid-20s to lower 30s.
Tuesday: low pressure center stays south of the area, sliding
off the coast south of Long Island on Tuesday. Model guidance is
now in fairly good agreement that the 0c isotherm in the mid
levels will reach the northern tier of PA Tuesday morning
(although the GFS is still a warmer outlier, bringing the warm
air aloft north of the New York southern tier). Current forecast now
has a wintry mix of light sleet, freezing rain and rain across
much of NE PA on Tuesday...except snow/sleet mix across the far
northern tier of PA and right along the New York/PA border and rte 17
corridor in New York. Further north expect periods of light to
occasionally moderate snow to continue all day Tuesday.
Temperatures continue to hover in the mid-20s to lower
30s...except mid-30s in the Wyoming Valley. Total snow by
Tuesday evening is forecast to be 2-5 inches areawide, with up
to 0.15 inches of ice across the NE PA and Sullivan County New York
(especially the higher elevations). Winds shift out of the north
by Tuesday afternoon, increasing to around 8-15 mph. The snow
and wintry mix taper off from SW to NE late in the day or
evening...with just some lingering snow shower up north after
Short term /Tuesday night through Wednesday night/...
after the northeastern cyclone pulls away from New York and PA, a
Canadian flow will develop across Lake Ontario. Colder air will
filter into our region, and lake effect snow showers will form
downwind of Lake Ontario and Lake Erie.
A colder shot of air is forecast to arrive on Wednesday. Very
unstable profiles and favorable shear point toward snow squalls
with gusty winds developing during the day. Snow squalls could
produce low visibilities in snow and blowing snow.
Arctic air pouring into the region will allow temperatures to
drop into the single digits Wednesday night, with below zero
readings forecast over northeastern sections of Oneida County.
The combination of cold temperatures and gusty winds will
produce wind chill values between -5 and -15.
Long term /Thursday through Sunday/...
westerly flow across the Great Lakes will cause light lake
effect snow showers over northern and western sections of the
forecast area Thursday before high pressure builds in Thursday
night. Temperatures will drop into the single digits Thursday
night with below zero readings to the far north.
Chilly but quiet weather is forecast for Friday as temperatures
rise into the 20s.
A weak wave could produce isolated snow showers on Saturday and
Sunday. Temperatures will rebound into the middle 30s on
Saturday and the upper 30s on Sunday.
Aviation /12z Monday through Friday/...
Expect generally VFR conditions with sct to bkn clouds between
3.5 to 6k ft agl streaming across the area this morning. Cannot
rule out some tempo MVFR cigs near ksyr and krme until mid
VFR conditions are forecast to continue through the the daytime
hours today for most terminals. The except will be kavp where a
period of light snow is possible from about 14-17z this
morning, and tempo MVFR vsbys and/or cigs are possible.
Otherwise, expect mid and high level clouds across the rest of
the region today.
This evening, a period of steady snow will gradually lift north
from central PA into our area by late evening or overnight. The
snow should reach kavp between 17/01-04z...with conditions
quickly becoming MVFR/fuel alternate, then IFR prior to 17/06z.
Some sleet could mix in here toward Tuesday morning.
The snow should reach the southern tier of New York (kbgm/kelm)
between 17/03-06z...with restrictions developing here shortly
thereafter. The snow likely reaches kith between about
17/05-08z and finally ksyr and krme between about 17/08-11z.
Expect fuel alternate, then IFR or worse restrictions once the
snow begins for all terminals.
Tuesday...fuel alternate/IFR restrictions with a wintry mix and
periods of snow across the region.
Wednesday and Wednesday night...MVFR/IFR restrictions with snow
showers and squalls in cny. MVFR avp.
Thursday...VFR. Possible restrictions in cny due to lingering
lake effect snow showers.
Thursday night and Friday...VFR.
PA...Winter Weather Advisory from 6 PM this evening to 4 PM EST
Tuesday for paz043-044-047-048-072.
Winter Weather Advisory from 9 PM this evening to 4 PM EST
Tuesday for paz038>040.
New York...Winter Weather Advisory from 9 PM this evening to 4 PM EST
Tuesday for nyz022-024-055>057-062.
Winter Weather Advisory from midnight tonight to 6 PM EST
Tuesday for nyz015>018-023-025-036-037-044>046.