Gale Watch 23, NWS New York, NY

Area Forecast Discussion
National Weather Service New York NY
101 AM EST Wed Nov 15 2017

.SYNOPSIS...
High pressure builds over the Tri State Area tonight and
Wednesday. A warm front approaches from the southwest Wednesday
night, then lifts to the north Thursday morning, followed
quickly by a cold frontal passage Thursday afternoon. High
pressure builds into the region Friday. A complex low impacts
the area Saturday into Sunday, followed by high pressure
building in Monday and Tuesday.

&&

.NEAR TERM /THROUGH TODAY/...
The forecast has been updated to increase cloud cover,
particularly across eastern CT and Long Island based on
satellite. No other significant changes were made.

Showers offshore are associated with a weak surface trough and
low level moisture convergence. High-res models show little
overall movement to this activity, since surface trough should
remain nearly stationary, but gradually weakens everything thru
late afternoon as moisture convergence begins to diminish.

Cloudiness will be slow to erode however, as upper flow is
initially cyclonic, but ridging aloft and drying through lower
levels will allow skies to clear early tonight. Lows will fall
back into the upper 20s to mid 30s, except upper 30s in NYC.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
High pressure builds over region Wednesday, resulting in plenty
of sunshine and light winds, though we should see some increase
in mid and high clouds during afternoon ahead of next system. Highs
will reach mid 40s to around 50.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Watching a couple of systems which are both expected to bring a
round of showers and are followed by strong winds and
reinforcement of colder air - one Wednesday night into Thursday
and the second Saturday into Sunday.

For first system, upper ridge moves quickly offshore Wednesday
night and allows deepening trough to approach from eastern Great
Lakes. There are some differences among operational models as to
how fast and exactly where upper trough closes off, with 12z
ECMWF doing so much more rapidly, resulting in stronger
secondary low east of Long Island Thursday afternoon. Given this
is more of an outlier and doesn't have much support from
ensembles, which do not support such rapid deepening, prefer to
keep system progressive with cold front crossing area Thursday
followed by reinforcing shot of cold air on gusty NW winds.

We will have a quick break Friday as high pressure once again
builds over region. However, upper pattern remains progressive
and next system should already be on our doorstep Saturday
morning.

Once again there are timing differences among operational
models, with 12z GFS on faster side of consensus, bringing
showers into area Saturday morning as opposed to afternoon. This
faster timing is not preferred since upper trough should deepen
with time as it approaches area, resulting in slower onset of
showers, with most of rain falling from Saturday afternoon into
Sunday morning. However, if other models should trend more in
line with faster GFS, it would mean greater potential for light
snow or wintry mix at start across lower Hudson Valley late
Friday night or early Saturday morning.

This second system looks to be more robust than first once
according to ensembles, but nothing overly anomalous for this
time of year. Potential hazards include strong gusty winds, both
ahead of and behind system, due to strong low level jet.
Potential looks to be greater in cold advection pattern behind
it Sunday, when we could see NW winds gust as high as 35-45 mph.

System should exit quickly Sunday afternoon, with dry weather
expected Monday and Tuesday as high pressure builds over region.
However, with upper flow remaining cyclonic due to cutoff over
SE Canada, expect more in way of cloudiness and perhaps some
flurries across Orange County.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
High pressure remains centered over the northeast today.

VFR for the late night hours with NNE winds 5-10 KT. For Wednesday,
likely VFR all day, but late day or early evening MVFR cigs could
occur. Winds will veer E briefly before shifting SE during the
afternoon, remaining at 5-10 KT.

.OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.Wednesday night-Thursday...MVFR or lower in showers. W-NW winds G20-
30KT possible Thursday afternoon.
.Thursday night-Friday...VFR. NW winds G25-30KT, strongest
Thursday night.
.Saturday...Sub VFR conditions possible by the afternoon and
becoming likely towards evening. S-SW winds G25KT.
.Sunday...Conditions improve to VFR. NW winds G25-30KT.

&&

.MARINE...
Winds and seas expected to remain below Small Craft Advisory
levels tonight and Wednesday as high pressure builds over
waters.

Increasing southerly flow expected Wednesday night ahead of cold
front, which crosses area Thursday and should bring NW 20-30kt
gusts behind it Thursday afternoon into Friday morning. It's
possible gusts reach Gale force (34kt) on ocean waters south of
Long Island, but confidence is not high enough to issue Gale
Watches at this time, since it looks marginal.

High pressure briefly builds over waters Friday, resulting in
diminishing winds and seas.

Next strong cold front affects waters Saturday into Sunday.
Potential exists for Gale force gusts both ahead of, and
especially behind front Sunday into Monday, especially on ocean
waters south of Long Island.

Gale potential will continue to be highlighted in the Hazardous
Weather Outlook (HWO).

&&

.HYDROLOGY...
Looking at two rounds of rainfall over next few days - first
Wednesday night into Thursday and a second Saturday into Sunday.

Rainfall appears to be light with the first round, on the order
of up to 0.50 inch, which would have little impact on rivers and
streams.

There is the potential for heavier rainfall with the second
round Saturday into Sunday, but it is still too early to specify
amounts or possible impacts.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

Hazardous Weather Outlook
National Weather Service New York NY
Issued by National Weather Service TAUNTON MA
258 PM EST Tue Nov 14 2017

ANZ340-345-CTZ005>012-NJZ002-004-006-103>108-NYZ067>075-078>081-
176>179-152000-
Peconic and Gardiners Bays-
South Shore Bays from Jones Inlet through Shinnecock Bay-
Northern Fairfield-Northern New Haven-Northern Middlesex-
Northern New London-Southern Fairfield-Southern New Haven-
Southern Middlesex-Southern New London-Western Passaic-
Eastern Passaic-Hudson-Western Bergen-Eastern Bergen-Western Essex-
Eastern Essex-Western Union-Eastern Union-Orange-Putnam-Rockland-
Northern Westchester-Southern Westchester-New York (Manhattan)-Bronx-
Richmond (Staten Island)-Kings (Brooklyn)-Northwestern Suffolk-
Northeastern Suffolk-Southwestern Suffolk-Southeastern Suffolk-
Northern Queens-Northern Nassau-Southern Queens-Southern Nassau-
258 PM EST Tue Nov 14 2017

This Hazardous Weather Outlook is for Atlantic coastal waters,
southern Connecticut, northeast New Jersey and southeast New York.

.DAY ONE...This Afternoon and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time that would meet
National Weather Service warning criteria.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

&&

This Hazardous Weather Outlook provides a summary of potential
widespread hazardous weather events that may reach NWS warning
criteria. Most long fused NWS watches...warnings and advisories in
effect are highlighted.

Please refer to the latest NWS forecasts for weather not meeting NWS
warning criteria.

ANZ330-335-338-350-353-355-152000-
Long Island Sound East of New Haven CT/Port Jefferson NY-
Long Island Sound West of New Haven CT/Port Jefferson NY-
New York Harbor-Moriches Inlet NY to Montauk Point NY out 20 nm-
Fire Island Inlet NY to Moriches Inlet NY out 20 nm-
Sandy Hook NJ to Fire Island Inlet NY out 20 nm-
258 PM EST Tue Nov 14 2017

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...This Afternoon and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

There is the potential for gale force winds late Thursday afternoon
and Thursday night, and again from Saturday afternoon through
Sunday, especially on the ocean waters south of Long Island.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

&&

This Hazardous Weather Outlook provides a summary of potential
widespread hazardous weather events that may reach NWS warning
criteria. Most long fused NWS watches...warnings and advisories in
effect are highlighted.

Please refer to the latest NWS forecasts for weather not meeting NWS
warning criteria.