Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 080019
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
719 PM EST Wed Dec 7 2016

.SYNOPSIS...
Weak high pressure builds in tonight...followed by a series of
cold fronts cross the area Thursday through Saturday. High
pressure follows for Saturday night into Sunday. This moves
offshore and gives way to low pressure impacting the Tri-State
from Sunday night into Monday night. High pressure returns Tuesday
into Wednesday next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Weak northern stream ridging exits to the east this evening with
SW flow aloft in its wake tonight. This will maintain areas of mid
to high clouds overnight. With no shortwaves of note embedded in
the flow, it should be dry.

With breaks of cloud cover and light winds, brief windows for
radiational cooling should allow temps to fall into the mid-upper
20s across areas N&W of NYC metro. With dewpoints well in the 30s
today...patchy freezing of surface condensate is likely. If
clearing is more widespread, black ice potential and areal coverage
will increase across the outlying areas of the Tri- State.

For lows tonight a blend of MAV/MET/ECS guidance and NAM 2-meter
temperatures was used, with values a few degrees above normal.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A northern stream trough builds into the area Thursday and
Thursday night, with multiple shortwaves passing over the area as
the push around the base of the trough. The first shortwave passes
mainly to the north on Thursday and the second on Thursday night.
The passage of each shortwave will usher in a shot of
progressively colder air.

Dry low then mid levels should keep all areas dry through Thursday
evening. It appears that there should be sufficient moistening of
the low-mid levels by late Thursday night to warrant slight chance
of snow showers over the NW 1/3 of the CWA with flurries possible
elsewhere in response to the second shortwave.

Helping to usher in the cold air will be gusty w-nw winds
increasing to 20-30 mph Thursday night - with wind chills mainly
in the teens to lower 20s just before sunrise Friday morning.

Highs Thursday were based on a blend of MAV/ECS/MET guidance, NAM
2-meter temperatures and a mix down from 925-850 hPa per BUFKIT
soundings. Highs should be near normal - with some falling
temperatures by mid-late afternoon - especially over western
zones.

For lows Thursday night, a blend of MAV/MET guidance and NAM
2-meter temperatures was used, with readings around 5 degrees
below normal.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Overall a colder weather pattern is shaping up across the region for
the long term as conveyed by the upper level jet stream. For most of
the time, this jet will be situated south of the region.

In the mid levels, a fast quasi-zonal flow Friday through the
weekend will become more amplified next week. A small less amplified
shortwave moves across Saturday with a stronger one moving across
Monday through Monday night. Forecast ends with large amplified
trough or cutoff upper level low in Southeast Canada to the
Northeast U.S.

At the surface, a series of cold fronts move across Friday night
through Saturday. High pressure builds Saturday night through early
Sunday with a low pressure area then traveling towards the region
Sunday night through Monday as the high slides well offshore.
Uncertainty on exact position of surface low. For Monday night
through mid next week, high pressure returns, building in from the
west. Again, uncertainty here with position of high pressure and
whether it moves closer to region or stays farther west of the area.

In terms of weather, much colder air is expected Friday through
Saturday night. Temperatures do not get that much warmer for next
week, although Monday, with the development of return southerly
flow, temperatures are expected to be well into the 40s for a
majority of the region. Otherwise, looking at temperatures during
the day mainly 5-10 degrees below normal. In terms of precipitation,
snow showers are possible Friday and Saturday with a more widespread
precip event expected Sunday afternoon through Monday evening,
mainly stratiform. Uncertainty with position of parent low with
large differences in terms of precip. For example, latest ECMWF, 12Z
Wednesday, shows low well to the west, keeping mainly a rain event,
while other models show more of a snow potential inland. All
generally show more rain at the coast. Too early to tell with exact
rainfall amounts.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
High pressure slowly builds through Thursday.

Improvements to VFR will continue through this evening with VFR
forecast through the rest of the TAF period.

Winds at the city terminals will be out of the NE for the next
hour or so, but should shift back to the NW after 02Z. Wind speeds
should be between 5-10 kt. Winds outside the city terminals
become light and variable overnight with NW flow under 10 kt
continuing at city terminals. Winds back to the W Thursday, with
gusts 20-25 kt.

 ...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: NE flow through about 02Z, then winds should
shift back to the N then NW thereafter. Winds speeds should remain
below 10 kt.

KLGA TAF Comments: NE flow through about 02Z, then winds should
shift back to the N then NW thereafter. Winds speeds should remain
below 10 kt.

KEWR TAF Comments: NE flow through about 02Z, then winds should
shift back to the N then NW thereafter. Winds speeds should remain
below 10 kt.

KTEB TAF Comments: Wind speeds should remain less than 10 kt.

KHPN TAF Comments: No unscheduled amendments expected.

KISP TAF Comments: Improvement to VFR after 01Z expected.

.OUTLOOK FOR 00Z THURSDAY THROUGH MONDAY...
.Thursday-Thursday Night...VFR with W-NW G20-25KT. Flurries possible
Thurs night.
.Friday...VFR with NW gusts 25-30KT, diminishing to around 20KT at
night.
.Saturday...VFR.
.Sunday...Mainly VFR, slight chance of -SN in MVFR inland.
.Monday...MVFR or lower possible in chance rain/snow mix inland and
chance of rain near coast.

&&

.MARINE...
A relaxed pressure gradient will keep winds to 10 kt or less
through Thursday morning. However, a persistent ESE-SE swell will
keep seas in the coastal ocean waters at SCA levels through around
midnight, and possibly a tad longer. As a result, the SCA for
hazardous seas on the coastal ocean waters through 05Z tonight.

The pressure gradient tightens sharply Thursday afternoon over
the and remains fairly tight over all waters Thursday night. As a
result expect gusts to 25-30kt on the coastal ocean waters
Thursday afternoon and on all waters Thursday night.

Active period on the waters with at least SCA conditions Friday
through Saturday. Gales will be possible Friday through Friday night
for all waters. Sub SCA conditions mostly Saturday night through
Sunday with high pressure more in control. SCA conditions resume
Sunday night and continue into early next week, mainly on the ocean.

&&

.HYDROLOGY...
It should be dry through Thursday evening, then mainly dry late
Thursday night through Sunday.

There is a chance of a widespread 1/2 inch or more of precipitation
from Sunday night through Monday.

&&

.EQUIPMENT...
The New York City transmitter, KWO35, is off the air. Time for a
return to service is unknown.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory for hazardous seas until midnight EST
     tonight for ANZ350-353-355.

&&

$$
SYNOPSIS...Maloit/JM
NEAR TERM...Maloit/NV
SHORT TERM...Maloit
LONG TERM...JM
AVIATION...JP
MARINE...Maloit/JM
HYDROLOGY...Maloit/JM
EQUIPMENT...



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