Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 161444

Area Forecast Discussion
National Weather Service New York NY
944 AM EST Sat Dec 16 2017

Weak low pressure passes to the north today bringing a cold
front south of the region. High pressure builds in for tonight
and Sunday. Then a series of lows will pass through the area
through mid week.


Mean upper troughing continues over New England today with the
next vorticity maximum moving across the northern Great Lakes.
This energy will pass just to the north today. At the surface a
weak low will pass through New England. A cold front passes
through late this afternoon and into early this evening.

Some snow showers are possible this afternoon across the
interior as the front and upper energy approach. Drier low
levels across the region should prevent any widespread activity,
but some of these snow showers could translate towards to the
coast by early this evening as the cold front moves through. Do
not anticipate any accumulation other than possible a dusting
if a snow shower does occur.

Breezy westerly winds are forecast today with gusts 20-25 mph at
times. High temperatures will range from the lower and middle
30s inland to the upper 30s near the coast.


A few flurries may be lingering into the early evening hours if
the cold front is slower to push through. At this time will keep
the evening dry. Height rise tonight through Sunday as the flow
becomes more zonal. A dampening shortwave will be moving into
the weak upper ridge late Sunday and Sunday night, and pass
through Sunday night.


A weakening shortwave passes through Sunday night into Monday.
Have lowered the probabilities slightly as the shortwave is
weakening and flat, with little moisture. Warmer air will be
pushing into the region, and as the warm air lifts north of the
cold surface air a period of freezing rain, some ice pellets and
snow will be possible. Too early for specific details on this
light precip event.

Thereafter, models in fairly good agreement with the broad bu
shallow northern stream trough approaching the region on
Tuesday and sliding through during the midweek. At the surface,
the primary low pressure system rides through Quebec/Ontario
with trailing cold front approaching the region Tuesday Night.
Overall, appears to be mainly a light qpf event for the Monday
night into Tuesday evening period, due to limited interaction
between northern and southern stream. Thermal profile suggests
precip would be mainly liquid, but could be dealing with
freezing rain across interior Monday night as cold air
typically has a tough time scouring our in this setup.

Upper trough swings through the NE Tue Night into Wed with a
glancing shot of modifying arctic air in the wake of the cold
front for Wed/Thu.

Upper flow flattens and even becomes a bit ridged for Thursday
ahead of the next northern stream trough digging into the Upper
Plains, which should allow for a moderation in temps ahead of
next potential frontal system.


Weak low pressure tracks across New England today dragging a
cold front through this evening.

VFR with CIGS between 3-5 KFT developing from late morning
through the afternoon. Have kept CIGS above 3kft, but some
locations may drop to MVFR aft 16z. Don`t have high enough
confidence to include in TAFs attm, but amendments for this are
possible. Otherwise, localized MVFR or IFR conditions cannot be
ruled out in isolated rain or snow showers late in the day
mainly N and W of NYC terminals.

Westerly winds increase to 10 to 20 kt, with gusts 20 to 30 kt.
Gusts may linger a few hours longer than forecast, but are
expected to become less frequent after 20-21Z. Cold fropa
between 22z and 02z with winds veering to the NW and

.SUN...VFR during the day. Chance MVFR in a mix of -RA/-SN towards
.MON...Low chance MVFR in -RA for coastal terminals, light wintry
mix inland. Improvement as the day progresses.
.TUE...MVFR possible with a slight chance of showers.
.WED...VFR. NW winds G20-30KT.


Gusty small craft winds are likely across all the forecast
waters today into early this evening as a rather tight pressure
gradient moves through the waters as low pressure moves into the
Atlantic and high pressure builds to the west. Gusty winds may
linger into this evening on the ocean waters. Ocean seas may
remain around small craft levels into Sunday evening as well.
So, the advisory remains into this evening on the ocean.

The next chance for SCA conditions will be late Tuesday/Tue eve
ahead of approaching cold front, but higher likelihood of
widespread SCA Tuesday Night through Wednesday night with tight
pressure gradient and strong caa in wake of cold front. Gales
are possible during this time frame.


No significant hydrologic impacts expected.


NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the
air for an extended period of time.


MARINE...Small Craft Advisory until 7 PM EST this evening for ANZ330-
     Small Craft Advisory until 1 AM EST Sunday for ANZ350-353-355.


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