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Area forecast discussion 
National Weather Service New York New York
751 am EST Wednesday Feb 10 2016

Synopsis...
low pressure will track east of Montauk today...and into the North
Atlantic tonight. A cold front will pass on Thursday...followed by
weak high pressure on Friday. A strong Arctic cold front will
approach Friday night and pass through Saturday morning as a
developing ocean storm passes by to the southeast. Strong Arctic
high pressure will build across later Saturday into Sunday
night...then retreat to the northeast Monday into Monday night.
A low pressure system will approach on Tuesday.

&&

Near term /until 6 PM this evening/...
per current radar and extrapolated trend which matches hrrr fairly
well...light snow showers should continue until about midday.
No significant accums expected.

A shortwave over southern New Jersey and Delaware-Maryland-Virginia near District of Columbia will track east-northeastward
today...and is likely to remain just S of Long Island. If it were
to skirt Long Island...some places...particularly the South Shore
of eastern Long Island...could see an inch or two accumulation
late this morning into early afternoon.

The llvls dry out this afternoon with westerly flow...so snow chances decrease
through the day. There remains some weak lift in the nearly saturated
850 mb-700 mb region tonight. This level will be thermally conducive to snow
production. As a result...included flurries in the forecast.

Temperatures generally a blend of guidance...although trended highs
closer to the colder 00z NAM 2m temperatures due to the snow cover.

&&

Short term /6 PM this evening through 6 PM Thursday/...
500 mb trough axis...increasingly steep lapse rates and cyclonic flow
aloft should lead to scattered to numerous snow showers. Some of these could
be locally heavy with the NAM even producing about 100 j/kg of
SBCAPE. Went with coverage wording in the forecast. In addition to the
snow...winds should mix down on unidirectional flow aloft and
produce gusts to around 30 miles per hour. Brief periods of hazardous travel
will therefore be possible where the heavier snow showers occur.

&&

Long term /Thursday night through Tuesday/...
brisk northwest flow after cold frontal passage Thursday should peak during the
evening...with possibility of winds reaching advisory criteria in
NYC and across Long Island. These winds should diminish late Thursday
night...but will still be strong enough in tandem with low temperatures
in the single digits inland and teens NYC/coastal sections to
produce wind chills as low as 0 to 5 above.

Fair on Friday with highs in the 20s...then an Arctic cold front will
approach Friday night...passing through late at night or early Sat
morning. Meanwhile a strong shortwave embedded in the increasingly
amplified flow over the eastern Continental U.S. During this time should
initiate surface cyclogenesis along a baroclinic zone along the
Carolina coast on Friday...with the low passing to the southeast of Long
Island late Friday night into early Sat morning. These systems have
made a habit of tracking closer to the coast than model forecast...and
so increased guidance pop a little to bring chances to NYC east
for some light accumulation.

Then a quick shot of very cold air will overspread the area later
Sat into Sunday night. European model (ecmwf)/GFS agree on 800 mb temperatures as cold as -29c
to -30c approaching late Sat night...which supports forecast low
temperatures close to zero in NYC metropolitan and Long Island...0 to 5 below
most elsewhere...and a little colder in the interior valleys well
north/west of NYC. These temperatures combined with northwest winds 10-20 miles per hour
would produce wind chills of 15 to 20 below over most of the
area...and 25 below across the far interior.

This shot of frigid air should be short lived as the Arctic high
builds overhead Sunday night...then passes east Monday morning. With
the high overhead...forecast lows Sunday night of 10-15 in NYC and
single digits elsewhere could end up at least several degree colder
if cloud cover approaching from the west holds off until Monday.
Highs on Monday quickly moderate to 30-35.

Overrunning then sets up Monday afternoon/night ahead of an
approaching low pressure system...with potential for some light
snow accumulation during that time...then possibly some freezing
rain/sleet from NYC north/west late Monday night into Tuesday morning as
temperatures warm aloft but a wedge of low level colder air remains.
Temperatures should warm up well into the 40s Tuesday afternoon...changing
precipitation to all rain throughout by late morning or midday.

&&

Aviation /13z Wednesday through Sunday/...
a trough of low pressure moves north of the area this morning. Low
pressure remains northeast of the area into Wednesday night.

Mainly MVFR or VFR in light snow and drizzle this morning. There
will be some pockets of IFR as well. Conditions should improve to
VFR around 15z with precipitation coming to an end. Visibility
restrictions could fall to IFR in areas of snow.

Westerly winds 5 to 10 knots this morning. Gusts will develop around
midday. At the NYC metropolitan terminals gusts continue through tonight
while gusts subside at the remainder of the terminals.

New York 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: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher than
forecast this afternoon.

Klga fcster comments: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher than
forecast this afternoon.

Kewr fcster comments: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher
than forecast this afternoon.

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

Kteb fcster comments: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher
than forecast this afternoon.

Khpn fcster comments: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher than
forecast this afternoon.

Kisp fcster comments: amendments possible this morning for changing
flight categories due to snow. A few gusts may be higher
than forecast this afternoon.

Outlook for 12z Thursday through sun...
late Wednesday night...VFR. West gusts 20-25kt at the NYC metropolitan terminals.
Thursday...slight chance -shsn...otherwise VFR. West-northwest gusts 25-30kt.
Friday...VFR.
Sat-sun...VFR. Northwest gusts 20-30kt.

&&

Marine...
Small Craft Advisory conditions through tonight on the ocean. Reissued for New York Harbor where
gusts should peak around 25 knots late this afternoon and this
evening. All areas under a gale watch for Thursday and Thursday night with
increasing westerly flow.

Quiet daytime Friday with weak high pressure overhead...then Small Craft Advisory
conds likely on the ocean Friday night...then gales on the ocean Sat
into Sat night and Small Craft Advisory conds elsewhere after an Arctic cold
frontal passage. Small Craft Advisory conds all waters on Sunday should quiet down
again Sunday night as strong high pressure builds overhead.

&&

Hydrology...
light amts of snow can be expected today. Snow showers on Thursday will
produce basin average quantitative precipitation forecast of less than 1/10 of an inch.

Liquid equivalent quantitative precipitation forecast with an Arctic cold front and passing low to
the southeast late Friday night into Sat morning should be less than 1/4
inch...with any higher amts over southeast CT and eastern Long Island.

A low pressure system impacting the area from Monday night into Tuesday
has potential to bring significant quantitative precipitation forecast of over an inch...with most
of the precipitation Monday night falling as light snow...then as moderate
to heavier rain on Tuesday.

&&

Tides/coastal flooding...
a gradual downward trend in surge and astronomical tides expected
over the next couple of days.

Surge lowers for the high tide cycle this morning...with minor
coastal flooding for the more vulnerable locales of the Long
Island South Shore bays...New York Harbor...NE New Jersey...and western Long
Island Sound.

Astronomical tides will continue to lower tonight...with any
brief localized minor impacts likely being relegated to the South
Shore bays of Long Island.

&&

Climate...
with the extremely cold air mass forecast Saturday into
Sunday...record minimums and record low maximums may be reached.
Here are the records and forecasts...

Station......record/fcst minimum...record low maximum/forecast high
for 2/14 for 2/14

NYC...........2 (1916) / 2.............17 (1979) / 16
LGA...........1 (1979) / 3.............15 (1979) / 18
JFK...........4 (1979) / 2.............17 (1979) / 17
isp...........7 (2015) / 0.............26 (1987) / 15
ewr...........0 (1979) / 0.............15 (1979) / 19
bdr...........3 (2015*) / -1.............18 (1979) / 15

*in 1979 as well

&&

Okx watches/warnings/advisories...
CT...coastal Flood Advisory from 11 am this morning to 3 PM EST
this afternoon for ctz009.
New York...coastal Flood Advisory from 11 am this morning to 3 PM EST
this afternoon for nyz071-078-177.
Coastal Flood Advisory until noon EST today for nyz074-075-080-
178-179.
New Jersey...coastal Flood Advisory until noon EST today for njz006-106-108.
Marine...gale watch from Thursday morning through late Thursday night
for anz330-335-338-340-345-350-353-355.
Small Craft Advisory from 2 PM this afternoon to 10 PM EST
this evening for anz338.
Small Craft Advisory until 6 am EST Thursday for anz350-353-
355.

&&

$$
Synopsis...jmc/Goodman
near term...jmc/Goodman
short term...jmc
long term...Goodman
aviation...British Columbia
marine...jmc/Goodman
hydrology...jmc/Goodman
tides/coastal flooding...
climate...

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