NWS Forecast Discussion - New York City Area

Forecast Discussion for OKX NWS Office
666
FXUS61 KOKX 160957
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
457 AM EST Sat Feb 16 2019

.SYNOPSIS...
High pressure will build in through Sunday morning, then pass
east Sunday afternoon. Weak low pressure will approach from the
west Sunday night, then pass just south and east late Sunday
night into Monday. High pressure will then return for Tuesday,
followed by another low pressure and frontal system mid week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Skies should start off partly to mostly cloudy across Long
Island and SE CT early this AM as some high/mid clouds linger,
then become mostly sunny throughout as the high builds. High
temps should be in the lower 40s, which is about average.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
High pressure will continue to build in Saturday night with
mostly clear skies. Conditions are more favorable for
radiational cooling versus tonight, and combined with a colder
air mass, temps should drop into the teens across parts of the
Lower Hudson Valley, interior CT, and the Pine Barrens of
eastern Long Island. The rest of the area should have lows in
the 20s.

Most of Sunday will feature mostly sunny skies as the axis of
the high slides across. Clouds then lower/thick in the afternoon
from NYC metro west as a flat upper ridge axis passes. High
temps will be in the mid/upper 30s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
As mid level shortwave energy shears eastward from a weak
closed low over the northern Plains, flow aloft becomes SW, and
associated sfc low pressure moves across the OH valley, light
snow should develop Sunday evening, that could briefly start off
as a snow-rain mix in/near NYC. There is some question as to
how quickly this system passes across, which would impact precip
types and their timing late Sunday night. The NAM/ECMWF are
generally faster than the GFS, and with more mid level warming
via their faster WSW flow aloft. ECMWF also drier presumably
given its mid level confluent flow aloft extending a little
farther south than that of the GFS, but the NAM remains just as
west as the GFS given the same general flow aloft. As a result
went generally with a 2:1 NAM/GFS blend on thermal profiles,
and an even split on ECMWF/GFS QPF, with light snow mixing with
or changing to freezing rain across Long Island, NYC metro, and
the lower Hudson Valley late Sunday night. Fcst snow amounts
still in the 1-2 inch range.

As mid levels dry on on Monday following passage of the sfc low
to the southeast, ice nucleation unlikely to occur aloft, and
so any lingering precip on Monday should be either light
freezing rain/drizzle or plain rain/drizzle. Freezing rain
should change to rain closer to the the coast during the
morning, but hang in across the interior into early afternoon.
Ice accumulation should be minimal, with no more than a few
hundredths of an inch at most, and on top of already-fallen
snow, so less of a hazard than if on bare ground.

High temps on Monday should range from the lower 30s across most
of the interior, to near 40 in NYC.

High pressure builds across the Great Lakes Monday night and
Tuesday, then next low approaches from the southwest for Tue
night- Wed. Based on upper steering flow as mentioned, the
southern low likely passes well to the west, then NW. Meanwhile,
high pressure settles across northern New England, likely
resulting in some cold air damming as another low develops along
the mid Atlantic. Still a lot of details to iron out here, but
snow is possible late Tuesday night/Wednesday, then a changeover
to a wintry mix to rain would likely occur Wed night-Thu before
ending. Dry Friday behind the system.

In general, temperatures should remain slightly below normal,
but Arctic air is not anticipated.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
On the heels of a cold frontal passage, Canadian high pressure
will build into the region through Saturday night.

VFR.

W winds at the beginning of the forecast period will shift to the NW
as high pressure builds into the terminals. Winds may be around 310
true for several hours from around 06Z to 12Z, with occasional gusts
up to 20 kt at the coastal terminals. During Saturday winds
will be more from the NW to N around 10 kt. Saturday night winds
become northerly, 10 kt or less.

.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.Late Saturday night-Sunday...VFR.
.Sunday night-Monday...Chance of wintry mix with MVFR or lower
conditions possible.
.Tuesday...VFR.
.Wednesday...Chance of snow with MVFR or lower conditions
possible.

&&

.MARINE...
SCA remains in effect for the ocean waters into this afternoon
as seas gradually subside through the day. Winds remain below
SCA levels.

High pressure then builds across the waters through Sunday with
sub-SCA conditions through Sunday night.

Low pressure passes to the south and east Sunday night into
Monday with a brief period of E-NE winds 10 to 20 kt, strongest
east of Moriches Inlet where seas may approach 5 ft. NW winds on
the backside of the low may gusts up to 20 kt Monday night.

High pressure follows for Tuesday with winds and seas
increasing late Wednesday into Thursday as another low and
frontal boundary approaches.

&&

.HYDROLOGY...
There are no hydrologic concerns through the middle of next
week.

&&

.EQUIPMENT...
NYC Central Park winds are out of service until further notice.
Loss of data is due to a severed cable. Parts are on order.

NYC NOAA Weather Radio Station KWO35 (162.55 MHz) will remain off
the air for an extended period of time.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ353-
     355.
     Small Craft Advisory until 4 PM EST this afternoon for ANZ350.

&&

$$

SYNOPSIS...Goodman/PW
NEAR TERM...Goodman
SHORT TERM...Goodman
LONG TERM...Goodman/PW
AVIATION...MET/DW
MARINE...DW
HYDROLOGY...Goodman/PW
EQUIPMENT...//

NWS OKX Office Area Forecast Discussion