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Area forecast discussion 
National Weather Service New York New York
1236 am EST Monday Feb 8 2016

Synopsis...
intensifying low pressure along the southeast U.S. Coast will
track to the north overnight and will pass well south and east of
Long Island on Monday. That low then tracks into the Canadian
Maritimes Monday night. An upper level system will then spin over
the region through the end of the week. An Arctic airmass
overspreads the area for the weekend.

&&

Near term /through today/...
minor changes were made with this update to reflect the latest
trends in observations and guidance. The forecast appears on
track.

21z sref mean snow accumulations through 00z Tuesday are in
general in line with current snow forecast. 00z NAM has come in a
tad drier than previous run...however last few runs of hrrr
suggest that at least over warning area...that by 16z generally
are near forecast current forecast quantitative precipitation forecast amounts through 00z
Tuesday. So given this...have made only minor changes to snow fall
forecast...mainly to reflect slightly slower onset per latest hrrr
and NAM.

Still appears the highest quantitative precipitation forecast amounts will fall over eastern Long
Island and southeast CT...where 4 to 8 inches of snow is possible. Winter
storm warnings have been issued for those areas.

Elsewhere...snow will be lighter over the rest of the County Warning Area...and
expecting a sharp cutoff from where snow falls and where it does
not. Went ahead and hoisted winter weather advisories for the rest
of CT and Long Island...and for Westchester and NYC as well...as
snow accumulations of 2 to 4 inches is possible in those
locations throughout the period. West of that line...only about 1
to 3 inches of snow is possible for NE New Jersey and the rest of the
lower Hudson Valley...so no headlines issued for those areas.

With a tight NE pressure gradient developing...can expect strong winds
of 15-25 miles per hour with gusts occasionally as high as 35 miles per hour in the
warning areas. Not expecting 3 hours of 35 miles per hour winds and/or
visibilities less than 1/4 mile...hence the Winter Storm Warning
as opposed to a Blizzard Warning. But blizzard-like conditions possible
in the warning areas. With a heavy...wet snow expected...downed
trees and power lines are possible.

Elsewhere...winds will not be quite as strong...but gusts to 30
miles per hour possible for coastal areas.

Lows overnight will drop into the middle 20s to low 30s. Highs on
Monday will top off in the low to middle 30s.

&&

Short term /tonight through 6 PM Tuesday/...
snow tapers off Monday evening. As low pressure from the Ohio Valley
tracks east...a secondary low looks to form off the middle-Atlantic
coast. Hard to say where the heaviest precipitation will set
up...but light snow is likely through the night.

&&

Long term /Tuesday night through Sunday/...
models continue to be in good agreement with respect to the
pattern through the end of the week. Cyclonic flow aloft plus low
level lapse rates approaching dry adiabatic at times will produce
periods of light snow. Wet bulb zero heights at or below 500ft
through the period so all snow is forecast. Breaks in the clouds
will be needed for temperatures to reach superblend numbers...so
dropped them down a degree for now. For snow
accumulations...mainly light amounts in the grids at this time.
However...there is the potential for two periods of enhanced
precipitation as weak lows get spun up offshore in the Tuesday time
frame and Wednesday time frame. It is too far out to pinpoint exactly
where any heavier bands set up...but the potential for at least a
moderate snowfall in the Tuesday-Wednesday period is there. A first wave of
colder air comes in on Thursday. Very steep low level lapse rates again
so any moisture in the area should be squeezed out with more light
snow. Snow chances lessen on Friday at this time with the middle level
moisture exiting the area. The Arctic front looks to be Friday night
setting the stage for a frigid weekend. Perhaps some flurries or
snow showers Sat...then dry on sun with a 1040s hi building in
from the west.

&&

Aviation /06z Monday through Friday/...
intensifying low pressure along the southeast U.S. Coast will track
to the north this morning and will pass well south and east of Long
Island into tonight.

VFR through 07z or so. Then MVFR to IFR conditions likely to develop
in light snow from east to west through around 13z for city
terminals...and then to IFR from east to west through midday. The
exception is at kswf...where MVFR conditions are not expected until
around noon...with currently no IFR conditions forecast there.
Also...at kgon/kisp...expect LIFR after 12z through 19-20z with
moderate to heavy snow. There is a low chance for LIFR at city
terminals and kbdr. Conditions should improve to MVFR at city
terminals around 20z.

Winds increase out of the NE then north early this morning. It appears
frequent gusts should hold off until around/just after day
break...with gusts of 20-30kt likely...and peak gusts up to 35 knots
possible at coastal terminals. Exception is at kswf where gusts to
only around 15 knots are forecast. Gusts should begin to diminish
around/after 20z.

Likely snowfall accumulations of: less than 1 inch for kswf 1 to 3
inches across khpn/kewr/kteb 2 to 5 inches for klga/kjfk/kbdr 4 to 8
inches for kisp/kgon

Outlook for 06z Tuesday through Friday...
late Monday night-Thursday...MVFR or lower likely in intermittent
snow. North-NE winds g15-20kt possible Monday night-Tuesday
night...then west-northwest winds g15-25 knots possible Wednesday-Thursday.
Thursday night-Friday...mainly VFR...but potential for scattered
MVFR conditions in strato-cumulus and flurries. West-northwest winds g15-25kt
possible.

&&

Marine...
minor changes were made with this update to reflect the latest
trends in observations and guidance. The forecast appears on
track.

A tight pressure gradient sets up on the waters with gale force winds
on the ocean...eastern Long Island Sound...and eastern Long
Island bays and Small Craft Advisory level winds on New York
Harbor...western Long Island Sound...and the South Shore bays.

A few gusts to storm force are possible on eastern ocean
waters...but confidence not high enough to upgrade to a warning.

Winds diminish fairly quickly Monday evening as low pressure departs.
Seas on the ocean will remain high...as it will take some time for
the seas to settle.

Headlines for the gale warnings and small craft advisories
largely unchanged.

Small Craft Advisory conditions on the ocean Tue-Sat. Periods of Small Craft Advisory level winds
likely in the Tuesday-Sat period elsewhere.

&&

Hydrology...
liquid equivalent quantitative precipitation forecast will range from less than a tenth of an inch
west of the Hudson River to almost an inch over southeast CT and far
eastern Long Island. The precipitation will fall as snow...so no
hydrologic problems anticipated. Measurable precipitation is then
likely through at least the middle of next week. Amounts appear
to be generally light at this time and all in the form of snow.

&&

Tides/coastal flooding...
potential for minor to locally moderate coastal impacts Monday
into Wednesday with a new moon on Monday and a series of low
pressures affecting the region.

An intense low pressure tracking southeast of the region Monday will
result in NE/north winds increasing to potentially gale force tonight
and continuing into Monday. Based on a track of intensifying low
that should be southeast of the 40/70 latitude/Lon benchmark and cold air
damming signature...would expect winds to be backed more to the north
than NE. This should favor the lower surge guidance for the Monday
morning and night high tide cycles...which will keep flooding
minor and limited to the typically vulnerable locales. Isolated
moderate flooding possible along the most vulnerable shore bays of
Nassau County. Due to the lower astronomical tides on Monday
night...water levels should be a bit lower...with minor flooding
mainly limited to the South Shore bays of Long Island/New York and
along the North Shore of Long Island adjacent to western Long
Island Sound.

As we head into tuesdays high tide cycles...winds should veer
more to the NE as additional wave/S of low pressure track to the
south of the region. The Spring astronomical tides and multi-tidal
cycle nature of the event will favor additional minor
flooding...with potential for widespread minor to moderate
flooding in the South Shore Bay areas Tuesday. Surge should
decrease heading into wednesdays high tide cycle...but lingering
minor coastal flooding is still possible...particularly int he
South Shore bays areas.

High surf of 6 to 10 feet will once again present a moderate to
high threat for areas of dune toe erosion along the Atlantic Ocean
beaches...and a localized potential for overwashes on Fire
Island. This is based on modeled impacts of gale center from the
USGS coastal change hazards Portal.

&&

Okx watches/warnings/advisories...
CT...Winter Storm Warning until 6 PM EST this evening for ctz007-
008-011-012.
Winter Weather Advisory until 6 PM EST this evening for ctz005-
006-009-010.
Coastal Flood Advisory from 10 am this morning to 1 PM EST
this afternoon for ctz009-010.
New York...Winter Storm Warning until 6 PM EST this evening for
nyz078>081.
Coastal Flood Advisory from 7 am to 11 am EST this morning for
nyz074-075-080-081-178-179.
Winter Weather Advisory until 6 PM EST this evening for
nyz070>075-176>179.
Coastal Flood Advisory from 10 am this morning to 1 PM EST
this afternoon for nyz071-073-078-177.
High surf advisory until 7 am EST Tuesday for nyz080-081-178-
179.
Coastal Flood Advisory from 7 PM to 11 PM EST this evening for
nyz075-080-178-179.
Coastal Flood Advisory from 10 PM this evening to 1 am EST
Tuesday for nyz078-177.
New Jersey...coastal Flood Advisory from 7 am to 11 am EST this morning for
njz006-106-108.
Marine...Small Craft Advisory until 6 PM EST this evening for anz335-
338-345.
Gale Warning until 6 PM EST this evening for anz330-340-350-
353-355.

&&

$$
Synopsis...jmc/mps
near term...jmc/maloit/mps
short term...mps
long term...jmc
aviation...maloit
marine...jmc/maloit/mps
hydrology...jmc/mps
tides/coastal flooding...

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