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Area Forecast Discussion
National Weather Service New York NY
634 AM EDT Sun Oct 23 2016

Strong low pressure over eastern Canada will gradually weaken
over the next couple of days, while a clipper low and its
associated cold front move through the area early Monday morning.
High pressure builds across the area Tuesday and Wednesday,
followed by a Pacific frontal system at the end of the week.


Minor adjustments made to forecast based on current conditions.

Deep low pressure over eastern Canada today will begin to
gradually weaken, while a clipper low approaches from the Great
Lakes. Winds are expected to vertically mix more than the previous
day. However, gusts are expected to peak out occasionally closer
to 35 kt as opposed to the 40 kt on Sunday due to slightly weaker
winds at the top of the mixed layer. Thus, no wind advisory.

Short wave ridging aloft combined with the westerly flow should
keep skies mostly sunny today. Warm advection this afternoon may
result in skies going partly cloudy for a time.

Highs today will be close to seasonable levels, from the upper
50s to lower 60s.


Clipper low races east tonight and passes through the area after
midnight. Decent lift along and ahead of the associated mid level
short wave will result in a brief period of rain with up to a
quarter inch possible. Most locations will dry out by daybreak
Monday with the possible exception of far eastern LI and SE CT.

Cold advection will follow through the day Monday with another
shot of cold air following a short wave trough Monday evening.
Amplifying upper ridge over the western U.S. ahead of the next
Pacific storm system will help to amplify the downstream trough
across eastern Canada and the northeast. In addition, an upstream
block resides across the central Atlantic. This will result in a
deep-layered NW flow across the area with a shot of unseasonably
cold air to arrive Monday night and persist into mid week.

Gusty northwest winds will continue during this time with weakening
low pressure over eastern Canada and polar high pressure building
southeast from central Canada.


Upper trough remains across the northeastern portion of the country
early to mid week, as ridge to the west eventually flattens per
global models. Differences arrive with handling of shortwave that
develops across the upper mid west as it traverses east late in the

At the surface, low pressure associated with lingering upper trough
moves slowly across eastern Canada, as high pressure builds out of
central Canada and into the Great Lakes Region through mid week. The
high briefly slides across the area Thursday before giving way to
low pressure Thursday and Friday. Frontal boundaries, first warm
front followed by the cold front, impact the area from late
Thursday, into Friday. For Saturday, forecast becomes less clear. A
possible weak frontal boundary may move through Saturday, but
confidence in this remains low at this time.

Generally dry conditions are anticipated through Wednesday night
as high pressure slowly builds. Cyclonic flow could result in
more cloud cover each day, especially into New England Tuesday and
possibly Wednesday.

The best chance for rain looks to be late Thursday, Thursday night
into Friday. ECMWF slower with upstream system compared to usually
quicker GFS.

Temperatures will be below normal Tuesday and Wednesday, then slowly
moderate closer to normal Thursday through Saturday.


Strong low pressure moves into Quebec today. A cold front moves
through tonight into early Monday which will bring a brief period
of light rain to the terminals. MVFR will be possible but
confidence is not high so kept conditions VFR with visibilities of
6SM during the light rain.

VFR conditions are expected. Winds remain gusty, up to 25-35kt,
through today before becoming more intermittent and diminishing
tonight. However some additional gusts to near 20-25kt will
return late tonight into early Monday.

.Outlook for 06Z Monday through Thursday...
.Late Tonight-Monday Morning...Mainly VFR. MVFR possible with
light rain. Gusty SW-NW flow.
.Monday Afternoon-Tuesday Night...VFR. NW winds G20-25KT. Winds
diminish Tuesday night.
.Wednesday-Thursday...Mainly VFR.


On the synoptic scale, there will be a steep pressure gradient
between a deepening low traveling northward in Quebec and a high
pressure area centered in the Southeast. This will keep gales
across all waters especially with mixing depth increasing this
morning into this afternoon.

The pressure gradient weakens tonight with a clipper type low
passing through the area. The result will be wind gusts becoming
more occasional and diminishing. SCA conditions will be likely early
in the evening, but will eventually just be confined to the ocean
waters. However, after the associated cold frontal passage, winds
will resume gusting. Again, SCA conditions will be probable across
much of the waters for Monday through Tuesday. Winds diminish again
with a more substantial decrease of the pressure gradient Tuesday
night with a Canadian high approaching. High pressure remains
across the waters through early Thursday.


Up to a quarter inch of rain is possible tonight with a fast
moving area of low pressure. Rainfall of 1/2 inch or more is
possible Thursday into Friday. No hydrologic impacts are


MARINE...Gale Warning until 6 PM EDT this evening for ANZ330-335-338-




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