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

Synopsis...
an intense storm east of Cape Hatteras will move northeast today
and pass south of Nova Scotia tonight. An upper level system will
then spin over the region through the end of the week. An Arctic
air mass overspreads the area for the weekend.

&&

Near term /until 6 PM this evening/...
radar shows band of moderate to heavy snow associated with 700 mb-5
frontogenesis poised to move across eastern Long Island over the
next hour or two...then spread northwest into much of the rest of the
area through the morning. With temperatures in the upper 30s and lower
40s along the coast and in NYC metropolitan...precipitation could be mixed with
rain at the very onset...but then evaporative/dynamic cooling from
aloft should quickly change precipitation over to snow. The snow will be
heavy at times this morning across much of Long Island and
southern CT...and based on recent runs of the rap/hrrr...
think heavier snow should make it farther west into southern CT
and expanded Winter Storm Warning to New Haven County. With NE
winds gusting to 35 miles per hour near blizzard conds are likely...especially
across The Forks and coastal southeast CT. The combo of strong winds and
heavy snow could also result in downed trees and power lines.

Farther west...snow should be on the light side...with lift
generated a middle level shortwave approaching from the west and the
right rear quadrant of an upper jet streak over interior PA/NY.
These areas should see a general 2-4 inch snowfall...and expanded
Winter Weather Advisory westward to cover all but Orange and western
Passaic counties.

Temperatures after snow begins will be around or just above
freezing...then slowly fall this afternoon into the upper 20s
inland and just below freezing at the coast.

&&

Short term /6 PM this evening through Tuesday night/...
steady snow should taper off this evening. As an upper trough
tracks east...surface low pressure will form off the middle Atlantic
coast...and bring light snow late tonight into Tuesday night. An
inverted trough will extend west from this offshore low...and could
be the focus for some moderate to heavy snow just to its north.
Hard to say exactly where this will set up at this time...and bears
watching especially for NYC metropolitan and Long Island.

&&

Long term /Wednesday 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 a period enhanced precipitation on Wednesday.

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 /10z Monday through Friday/...
deep low pressure over the western Atlantic will pass to the
east today.

Initial VFR conditions will deteriorate from east to west as
snow moves in. There will be a fine line and sharp gradient from
the lighter snow and heavier snow...but at this time...would
expect terminals east of NYC metropolitan to experience the brunt of
the storm/snow.

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 continue to increase out of the NE/north this morning. Gusts of
20-30 knots are likely this morning...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:
1 to 2 inches for kswf.
2 to 3 inches across khpn/kewr/kteb.
2 to 5 inches for klga/kjfk/kbdr.
4 to 8 inches for kisp/kgon.

..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: timing of MVFR to IFR may be off an hour or two
as snow approaches from the east. Snow accumulate of around 3 inches.

Klga fcster comments: timing of MVFR to IFR may be off an hour or two
as snow approaches from the east. Snow accumulate of around 3 inches.

Kewr fcster comments: IFR is possible if higher intensity snow moves
in from the east. Snow accumulate of 2 to 3 inches.

The afternoon kewr haze potential forecast is yellow...which
implies slant range visibility 4-6sm or greater outside of cloud.

Kteb fcster comments: IFR is possible if higher intensity snow moves
in from the east. Snow accumulate of 2 to 3 inches.

Khpn fcster comments: timing of MVFR to IFR may be off an hour or two
as snow approaches from the east. Snow accumulate of around 3 inches.

Kisp fcster comments: timing of IFR to LIFR may be off an hour or two
as heavier snow approaches from the east. Snow accumulate of around 4 to 8
inches. Near blizzard conditions are possible for a time late morning
into the early afternoon.

Outlook for 06z Tuesday through Friday...
late tonight-Thursday...MVFR or lower likely in intermittent snow.
North-NE winds g15-20kt possible tonight-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...
deepening low pressure will pass southeast of Long Island today.
Expect a tight pressure gradient over the waters with gale force
winds on the ocean...eastern Long Island Sound...and eastern Long
Island bays. 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.
Also...a few gale force gusts will be possible on the South Shore
bays...but confidence not high enough to upgrade to gales.

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...at least back to sub-Small Craft Advisory levels.

Headlines for the gale warnings and small craft advisories
remain 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 1/10-1/4 inch west of the
Hudson...to 1/4-1/2 inch NYC and western Long Island/CT...to
1/2-3/4 inch eastern Long Island/CT. 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 today into
Wednesday. New moon today...and a series of low pressures
will affect the region.

An intense low pressure tracks southeast of the region today and will
result in strong NE/north winds. 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 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 tonight and lightening
winds...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
ctz006>008-010>012.
Winter Weather Advisory until 6 PM EST this evening for ctz005-
009.
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.
Winter Weather Advisory until 6 PM EST this evening for
nyz068>075-176>179.
Coastal Flood Advisory until 11 am EST this morning for nyz074-
075-080-081-178-179.
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...Winter Weather Advisory until 6 PM EST this evening for njz004-
006-103>108.
Coastal Flood Advisory until 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/Goodman
near term...Goodman
short term...Goodman
long term...jmc
aviation...maloit/pw
marine...BC/jmc
hydrology...jmc/Goodman
tides/coastal flooding...precipitable water

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