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Area forecast discussion 
National Weather Service New York New York
410 am EST Tuesday Feb 9 2016

Synopsis...
an intense storm to the east will move northeast and pass south of
Nova Scotia tonight. An upper level system will then spin over the
region through the end of the week. Low pressure will be slowly
departing to the east Wednesday into Thursday. High pressure
builds for Thursday night and Friday. Another low moves through
the region Friday night into Saturday night. An Arctic airmass
builds into the region Saturday night through Monday.

&&

Near term /until 6 am this morning/...
multiple passing 700-500 hpa vorticity maxima overnight will bring
scattered snow showers to the region overnight. However...looking at
regional radar trends...also could see some localized snow
bands...with moderate to possible heavy snow fall. As a
result...while most areas will experience under an inch...could
see 1-2 inches of additional snow across mainly S CT zones
overnight.

Snow/probability of precipitation refined based on blend of hrrr/rap.

Otherwise...only minor changes were made to remainder of grids to
reflect the latest trends in observations and guidance.

&&

Short term /6 am this morning through 6 PM Wednesday/...
deep longwave trough aloft shifts closer to the region. This will
help energize surface low pressure to our south. Models in agreement
of an inverted trough extending from this low...and as the system
shifts north...it looks like at least the southern half of the County Warning Area
will likely see some snow from this. All models keep the axis of
heaviest quantitative precipitation forecast just to our south...so this will need to be monitored
for any further northward shift trend.

For now...will go with just a chance of light snow during the
daytime. High chance/likely probability of precipitation then for Tuesday night with the
combination of the trough and extra lift supplied from shortwave
energy aloft. Up to 2 inches of snow is currently forecast for
Tuesday night...but this can change depending on where the inverted
trough ultimately ends up.

&&

Long term /Wednesday night through Monday/...
a longwave eastern trough will remain Wednesday into Saturday with a
series of shortwaves rotating through the flow. The upper trough
axis finally moves to the east Saturday night into Sunday as a surge
of Arctic air...the coldest of the season...pushes into the
northeast Saturday night into Monday. Forecast and model guidance
remains very consistent through the extended period.

Cyclonic flow remains Wednesday with a trough remaining mainly north
of the area Wednesday as a surface low will be moving northeast
through the waters off the northeast coast. Cold air will be in
place and a chance of light snow or snow showers will continue
Wednesday into Thursday as the cyclonic flow continues.
Precipitation amounts are expected to be light...probably an inch or
so...mainly north. The first push of colder air into the area moves
in for Thursday behind the departing low. The area will be between
shortwaves Thursday night into Friday as weak surface ridging builds
in.

The next shortwave rotates through Friday night into Saturday night
with a surface low tracks north of the region. This low will bring
an Arctic front through the area with the coldest air of the season
moving in for Saturday night and remaining into Sunday. This low
brings another chance of light snow across the region. Arctic high
pressure builds in Saturday night and remains into the beginning of
next week. Right now the core of the coldest air looks to track west
of the region...moving through western New York state...western
Pennsylvania and into the central Appalachians.
Regardless...temperatures will be running 15 to as much as 25
degrees below normal. There will be a slight modification to the
airmass Monday. Currently widespread record lows are not expected
with the Arctic out break. The best chance will be Saturday
night/Sunday morning...see the climate section of the afd for
details.

&&

Aviation /09z Tuesday through Saturday/...
low pressure will track off the Carolina coast today and pass quickly
out to sea. Another weak low will pass S of the region tonight.

MVFR or lower through the taf period with periods of mainly light
snow or flurries. Chance for heavier snow tonight with accums in the
3-6 inch range and possible LIFR-vlifr visible at times.

NE flow generally at or below 10kt into Wednesday morning.

..NY metropolitan enhanced aviation weather support...

Detailed information...including hourly taf wind component forecasts can
be found at: http://www.Erh.NOAA.Gov/zny/n90 (lower case)

Kjfk fcster comments: VFR visible expected in any snow this morning.

Klga fcster comments: VFR visible expected in any snow this morning.

Kewr fcster comments: VFR visible expected in any snow this morning.

The afternoon kewr haze potential forecast is green...which implies
slant range visibility 7sm or greater outside of cloud.

Kteb fcster comments: VFR visible expected in any snow this morning.

Khpn fcster comments: VFR visible expected in any snow this morning.

Kisp fcster comments: VFR visible expected in any snow this morning.

Outlook for 06z Wednesday through Saturday...
tonight...IFR or lower likely with snow. Accums of 3-6 inches possible.
Wednesday...MVFR or lower likely in periods of light snow...
especially in the morning.
Thursday...slight chance of snow showers...otherwise VFR. Northwest winds
15-20 knots with gusts ot 25 knots possible.
Friday through Saturday...mainly VFR. MVFR possible in slight
chance of snow showers.

&&

Marine...
only minor changes were made to remainder of grids to
reflect the latest trends in observations and guidance.

Winds continue to slowly diminish...with gusts on the eastern
sound falling below 25 knots...so have cancelled the Small Craft Advisory there.

Small Craft Advisory level winds are still present on the coastal ocean
waters...and should diminish from west to east through the overnight
hours. As well as the eastern Long Island Sound. Small Craft Advisory remains up
this evening for eastern Long Island Sound due to this and some
higher 5 feet seas for extreme eastern Long Island Sound.

The ocean will have elevated seas lingering through Tuesday
night. Small Craft Advisory level winds also redevelop on the ocean Tuesday and
Tuesday night.

Non-ocean waters are expected to remain below small craft levels
through Wednesday...with winds 10 knots or less throughout by
Tuesday morning.

Small craft conditions will remain on the ocean waters Wednesday
into Friday as low pressure slowly departs to the east of the
forecast waters into Thursday night. Gusts Thursday on the remainder
of the forecast waters may reach small craft levels as the first
push of Arctic air moves in. There may be a brief lull in small
craft conditions later Friday into Friday night. Another low and an
Arctic front move through the waters late Friday night into Saturday
with small craft conditions likely once again.

&&

Hydrology...
only a light snow potential from now through Tuesday...so no
hydrologic problems anticipated.

Little precipitation...in the form of snow...is expected
Tuesday night through Saturday night. Dry weather is expected
Sunday and Monday.

&&

Tides/coastal flooding...
extended coastal Flood Advisory for SW Suffolk County until
midnight as water levels should not come below minor flood stage
until around then.

Also...monitoring The Battery closely...if departures do not fall
below 1.7 feet...currently at 2.2 feet and slowly falling by high
tide...could touch or just go above the minor coastal flood
benchmark with Tuesday mornings high tide. A coastal flood
statement might need to be issued depending on exactly how fast
the departure falls off.

Potential for minor to moderate coastal impacts into Wednesday
due to a recent new moon and a series of low pressures affecting
the region.

Strong offshore low pressure departs overnight. With lower
astronomical tides overnight and lighter winds...water levels
should be about 1/2 feet lower than this morning for most spots.
Expectation of widespread minor flooding for New York/New Jersey Harbor...South
Shore Bay of NYC...and western Long Island Sound. Moderate
flooding expected for the South Shore Bay locales along the
western Great South Bay.

For Tuesday morning high tide cycles...Spring astronomical tides
will peaking. In addition...winds should veer more to the NE as
additional waves of low pressure track to the south of the region.
Widespread minor coastal flooding is expected for most of the
region...with moderate coastal flooding for the South Shore bays
of Long Island and NYC. The high end of the forecast range could
come close to the water levels reached this morning for the bays
of NYC and western Long Island.

Thereafter...minor to moderate coastal flooding concerns possible to
continue into Wednesday high tide cycle. Moderate coastal flooding
potential greatest for South Shore Bay locales.

High surf of 6 to 10 feet will continue a moderate threat for 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...coastal Flood Advisory from 9 am this morning to 1 PM EST this
afternoon for ctz009-010.
New York...coastal Flood Advisory from 9 am this morning to 1 PM EST this
afternoon for nyz071-073-078-177.
Coastal Flood Warning until 11 am EST this morning for nyz075-
080-178-179.
High surf advisory until 7 am EST this morning for nyz080-081-
178-179.
Coastal Flood Advisory until 10 am EST this morning for nyz074.
Coastal Flood Advisory until 1 PM EST this afternoon for
nyz079-081.
New Jersey...coastal Flood Advisory until 10 am EST this morning for njz006-
106-108.
Marine...Small Craft Advisory until 6 am EST Wednesday for anz350-353-
355.

&&

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

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