Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 200021
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
721 PM EST Tue Feb 19 2019

.SYNOPSIS...
High pressure moves offshore tonight, followed by a low pressure
system that will impact the region Wednesday into Wednesday
night. A cold front follows on Thursday with high pressure
returning Thursday night through Saturday. Another low pressure
system then impacts the region Saturday night into Sunday.
High pressure builds back early next week.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Forecast on track this evening. Main concern will be thickness
of cirrus clouds that will stream through deep layered ridging
across the eastern states. These clouds may impact lows a bit
depending on how quickly they thicken overnight. The rest of
the atmosphere below is quite dry with high pressure over the
region.

Temperatures are expected to be below seasonable normals with a
modified Arctic air mass, and at least initially favorable
radiational cooling, before thicker clouds begin to move in
from the southwest ahead of developing low pressure. Expect lows
to range from the lower teens in typically cooler outlying
locations, to the mid 20s in New York City and surrounding metro
areas.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Initially dry conditions can be expected as high pressure shifts
offshore ahead of a developing low pressure system. With
increasing warm/moist advection, gradual saturation will occur,
allowing light snow to overspread the region from southwest to
northeast. At onset, snow may be lighter and fluffier due to a
cooler column, and may struggle to spread farther north and east
with the antecedent dry air mass.

By rush hour, roughly late afternoon into the evening, strong
frontogenesis will move through portions of northeastern NJ,
NYC, western Long Island and the lower Hudson Valley, allowing
for a temporary increase in rates, while temperatures continue
to rise. A quick burst of moderate snowfall will be possible,
but with the wetter snow, accumulations may not be as
significant. Overall consensus shows 1-3 inches possible for
these areas. A Winter Weather Advisory is now in place due to
the expected impact on the evening commute.

Snow then overspreads the remainder of the areas into the
evening, with similar impacts potential for the commute. Across
the southern most areas, snow will gradually transition to a brief
period of mixed precipitation before rain develops around
midnight. Across the interior, surface temperatures will
struggle to rise above freezing. Similar to the previous event,
dry air advects into mid and upper levels, hindering snow
growth, with low level warm advection supporting more of a
freezing drizzle profile. The advisory will remain in place due
to this potential for at least trace amounts of freezing rain.

Precipitation gradually begins to taper from west to east,
generally prior to the morning commute.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Rain tapers off Thursday morning as a coastal low pressure
moves off to the northeast. High pressure builds across the area
Thursday night. Temperatures on Thursday will rise into the low
to mid 50s with night time lows dropping into the upper 20s
inland and low to mid 30s along the coast. High pressure
dominates the region through a good part of Saturday with a
return to seasonable temperatures.

Another storm system impacts the area Saturday night into Sunday,
bringing another round of precipitation to the region.  Given the
surface low track north and west of the area, expect the
precipitation to be mainly in the form rain with some snow mix
possible overnight Saturday further inland. High pressure builds
back for the beginning of the week.

Temperatures will start out on Saturday in the low to mid 40s then
rise into the upper 40s to near 50 by Sunday, then return to
seasonable normals Monday and Tuesday.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
High pressure builds over the area tonight, then slowly slides offshore
into Wednesday evening, as a weak coastal low slides up the
Carolina coast.

VFR through Wednesday morning. MVFR then IFR conditions develop
from SW to NE Wednesday afternoon/early Wednesday evening in
snow. The snow should mix with sleet at KJFK and KEWR by around
23Z.

Winds become light and variable throughout tonight. SE winds
develop by tomorrow afternoon at less than 10KT then become east
by mid-late afternoon. Inland terminals could remain light and
variable on Wednesday.

 ...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: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow and any change over Wednesday afternoon/early Wednesday
evening.

KLGA TAF Comments: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow Wednesday afternoon.

KEWR TAF Comments: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow and any change over Wednesday afternoon/early Wednesday
evening.

KTEB TAF Comments: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow Wednesday afternoon.

KHPN TAF Comments: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow Wednesday afternoon.

KISP TAF Comments: Onset of light and variable winds could be
off +/- 1-2 hours. Low-moderate confidence in timing of onset of
snow Wednesday afternoon.

.OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
.Wednesday night...IFR or lower possible in a wintry mix
changing to rain. A prolonged period of freezing rain is
possible at KSWF. LLWS possible for coastal terminals mainly
after midnight.
.Thursday-Saturday morning...VFR. W-NW winds G15-25KT possible
from late Thursday morning into Friday morning.
.Saturday afternoon-Sunday...MVFR or lower in rain, with a
wintry mix possible across northern terminals Saturday afternoon
and night. SW-W winds G20-30KT possible Sunday.

&&

.MARINE...
Forecast on track on the waters this evening.

Winds and seas will remain tranquil into tonight as high
pressure moves over the waters. An area of low pressure is then
expected to impact the waters Wednesday night, allowing a brief
increase in winds and seas on the ocean. A Small Craft Advisory
is now in effect for Wednesday night.

SCA conditions expected Thursday through Thursday night. As high
pressure builds across the area waters, seas fall below SCA
conditions on Friday and remain below SCA levels through Sunday
before increasing back to SCA conditions Sunday night.

&&

.HYDROLOGY...
Liquid equivalent precipitation amounts Wednesday
into early Thursday morning will generally be around one half to
three quarters of an inch.

Another system may result in more wet weather late this weekend, but
it is too early to tell if any hydrologic will occur.

&&

.TIDES/COASTAL FLOODING...
There is a chance for some minor coastal flooding for high tide
cycles early Thursday, particularly across the South Shore Back
Bays of Long Island and Western Long Island Sound along the
shorelines of Southwest Connecticut.

&&

.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...Winter Weather Advisory from 3 PM Wednesday to 6 AM EST
     Thursday for CTZ005>012.
NY...Winter Weather Advisory from 3 PM Wednesday to 6 AM EST
     Thursday for NYZ078>081.
     Winter Weather Advisory from noon Wednesday to 6 AM EST
     Thursday for NYZ067>075-176>179.
NJ...Winter Weather Advisory from noon Wednesday to 6 AM EST
     Thursday for NJZ002-004-006-103>108.
MARINE...Small Craft Advisory from 6 PM Wednesday to 6 AM EST Thursday
     for ANZ350-353-355.

&&

$$

SYNOPSIS...MD/Fig
NEAR TERM...DS/MD
SHORT TERM...MD
LONG TERM...Fig
AVIATION...Maloit
MARINE...MD/Fig
HYDROLOGY...MD/Fig
TIDES/COASTAL FLOODING...
EQUIPMENT...



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