Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 082122
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
422 PM EST Thu Dec 8 2016

.SYNOPSIS...
A cold front will move across this evening, followed by another
cold front Friday afternoon. High pressure will builds over the
area Saturday and Saturday night, then slowly retreat to the
northeast early next week. A stationary front will set up south
of Long Island by late Sunday and remains into Monday night, as a
wave of low pressure rides along it. High pressure will build in
Tuesday and Tuesday night, followed by a coastal low passing to
the southeast Wednesday and Wednesday night.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
BKN high/mid clouds across NYC metro, Long Island, and SE CT
associated with upper jet will slowly move out this evening. Cold
front across eastern PA late this afternoon should swing across
tonight, with shot of CAA for tonight and skies becoming mostly
clear on a brisk W-NW flow. Temps tonight should fall to just
below freezing in NYC (and at Central Park for the first time
since April 10th), and into the 20s elsewhere. Wind chills will be
in the teens and 20s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Brisk NW flow will continue, gusting to 35 mph at times. Another
weak shortwave/cold front will move across Friday afternoon,
reinforcing the cold air already in place. Low level flow off Lake
Ontario should bring instability clouds, also scattered snow
showers well north/west of NYC and flurries elsewhere. Highs
across the area should remain in the 30s, which at Central Park
would be the first time since March 4th that the temperature
failed to break 40. This would also be the 2nd longest stretch on
record at the park with highs 40 or greater. Meanwhile wind
chills will be in the teens to near 20.

Clearing skies expected Fri night, but remaining brisk and cold,
with lows 15-20 well inland and across the Long Island Pine
Barrens, and 20-25 elsewhere. Wind chills will again be mainly in
the teens.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
A weak northern stream shortwave passes on Saturday, the atmosphere
above 700 hPa will be to dry to support any measurable
precipitation, however some stray flurries cannot be completely
ruled out. Highs Saturday were based on a blend of MAV/MET/ECS
guidance, NAM 2-meter temperatures and a mix down from775-750 hPa
per BUFKIT soundings. Highs should be around 5-10 degrees below
normal.

Zonal flow sets up aloft Saturday night, and with no shortwaves
forecast to be embedded in the flow, it should be dry. Lows Saturday
night were based on a blend of MAV/MET guidance and NAM 2-meter
temperatures and should be around 5 degrees below normal.

For Sunday-Monday night the models are coming into better agreement
that fast zonal flow will produce a weaker/flatter (more sheared)
system moving in from the Intermountain West starting Sunday
morning. The reduced amplification will result in weaker warm
advection ahead of the system, with the warm front now likely
staying S of Long Island through the event, with a secondary low
tracking to the S of Long Island along the front. Northern stream
ridging ahead of the system will support the forming of a high over
SE Canada which should server as a source for low level cold air by
Monday (NE- E flow over the region - typical of a cold air damming
pattern).

In terms of sensible weather, the aforementioned shortwave ridging
passing to the north Sunday should hold off anything other than very
light precipitation into Sunday afternoon - with snow across the
interior and rain elsewhere. The precipitation will become more
widespread and steady Sunday night and should chance to all snow
from N to S Sunday evening across the Tri-State. Snow continues into
Monday, with precipitation mixing with then changing to rain over
Long Island and at least Southern portions of NYC and maybe coastal
SW CT Monday morning and then to all rain Monday afternoon, except
for maybe far Northern portions of the CWA where a rain/snow mix
could linger. Precipitation should taper off from W to E Monday
night as the low exits to the southeast of Cape Cod mainly as Snow
N of Long Island Sound and Rain to the south.

Northern Stream ridging builds in Tuesday then exits to the east
Tuesday night, keeping things dry.

The extended forecast then becomes uncertain Wednesday/Wednesday
night in terms of timing/track of a coastal low passing to the
southeast. It should be cold enough for interior regions to see
mainly snow (if they see any precipitation) and coastal areas a
wintry mix. There is also some question on how cold it will be on
Wednesday - which plays into precipitation type.

Thursday should be dry and cold on WNW-NW flow aloft. The degree of
cold is in question - with the GFS having 850 hPa temperatures at or
below -18C and the ECMWF at or below -10C. This is the difference
between highs mid 30s to around 40 ECMWF and around 20-mid 20s GFS.
There is more evidence pointing towards the colder vice warmer edge
of the things, so weighed more towards the GFS (temperatures mainly
in the mid-upper 20s). Gusty NW winds should produce wind chills
Thursday afternoon from around 10 degrees across the northern
interior to lower-mid teens across urban NE NJ/NYC/Long Island.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
A cold front passes this afternoon. High pressure then builds
through Friday.

VFR through the TAF period.

W-WNW winds continue through tonight. Gusty winds have developed
and will continue tonight before relaxing somewhat overnight.
Gusts could become more occasional overnight, especially at
outlying terminals. Winds and gusts will increase after sunrise
Friday with gusts 25 to 30 kt late morning into the afternoon.

     NY Metro Enhanced Aviation Weather Support...

Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90

KJFK TAF Comments: Wind direction will stay left of 310 magnetic
through this evening.

KLGA TAF Comments: Wind direction will stay left of 310 magnetic
through this evening.

KEWR TAF Comments: Wind direction will stay left of 310 magnetic
through this evening.

KTEB TAF Comments: Gusts may begin 1-2 hours later than forecast.


KHPN TAF Comments: Gusts could become more occasional after
sunset.


KISP TAF Comments: Gusts may begin 1-2 hours later than forecast.

.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
.Friday afternoon...Flurries or snow showers possible mainly NW
of NYC metro. NW winds G20-30KT.
.Saturday...VFR.
.Sunday...Mainly VFR. Chance of light snow late.
.Sunday night and Monday...MVFR or IFR in snow Sunday night,
changing to mixed precipitation near the coast on Monday.
.Tuesday...Mainly VFR.

&&

.MARINE...
SCA in effect for all waters as a cold front passes through. There
could be a few gusts up to 35 kt on the ocean late tonight. Gale
Watch has been issued for the ocean for Friday into Friday night
as potential for gales increases. Winds should gradually diminish
Fri night, with SCA conds remaining only on the ocean and the
eastern Sound/bays after midnight.

SCA conditions should return to all waters on Saturday, and remain
on the coastal ocean waters into Saturday night. Winds should
subside to 10 kt or less on all waters Sunday morning, then
increase to 10-15 kt by Sunday night and remain so over the ocean
waters through Tuesday. There is a chance for gusts to around 25
kt on the coastal ocean waters Sunday afternoon and night. On the
non-ocean waters winds should be 10 kt or less Monday-Tuesday,
except maybe reaching 15 kt over eastern Long Island sound on
Monday.

&&

.HYDROLOGY...
There is the potential for 0.5-1 inches of liquid equivalent
precipitation from late Sunday into Sunday night.

&&

.EQUIPMENT...
New York City NOAA Weather Radio NWR transmitter KWO-35 is back in
service.

Central Park (NYC) observations (METAR) are still unavailable
due to an area power outage.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST Saturday for ANZ330-335-
     338-340-345.
     Gale Watch from Friday morning through late Friday night for
     ANZ350-353-355.
     Small Craft Advisory until 6 AM EST Friday for ANZ350-353-355.

&&

$$
SYNOPSIS...Goodman/Maloit
NEAR TERM...Goodman
SHORT TERM...Goodman
LONG TERM...Maloit
AVIATION...CB/DS
MARINE...Goodman/Maloit
HYDROLOGY...Goodman/Maloit
EQUIPMENT...



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