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-- Discussion containing changed information from previous version are highlighted. --
235
FXUS61 KOKX 250223
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1023 PM EDT Sat Sep 24 2016

.SYNOPSIS...
High pressure over southeast Canada builds across the area through
Sunday night. The high slides offshore on Monday. A frontal
system moves through on Tuesday. High pressure tries to returns
for the mid to late week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
The forecast is on track. Only made minor adjustments to hourly
temps and dewpoints, and lowered the low temperature forecast by
a couple of degrees in the Pine Barrens Region and surrounding
areas.

The first real autumn airmass of the season will be with us
through the weekend as a deep upper trough tracks SE across
eastern Canada and the northeast. At the same time, polar high
pressure centered over Ontario builds southeast toward the region.

This will result in a northerly flow with clear skies and
overnight lows several degrees below normal. Lows will range from
the lower 40s well inland and in the Pine Barrens Region of LI,
to the lower and mid 50s NYC metro.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Unseasonably cool conditions are on tap for Sunday and Sunday
night as polar high pressure over eastern Canada builds across the
region. Northerly winds will continue to allow dry, cool air to
filter into the region. Highs on Sunday will struggle to get into
the mid and upper 60s, with lows Sunday night ranging from the
upper 30s in the coldest locations, to the lower 50s NYC metro.

There remains a high risk for rip current development at ocean
beaches through Sunday evening due to a 4-5 ft long period se
swell.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Models in good agreement with deep layered ridging sliding east on
Monday...allowing a deep closed low to slide over the Great
Lakes/Southern Ontario. General agreement in the upper low sitting
over this region through midweek...before model divergence in
evolution and opening on the low for the late week period.

At the surface...high pressure slides east on Monday...while a cold
front associated with the stacked Great lakes low approaches the
region Monday Night...and crosses the region Tuesday. Some timing
differences exist...but overall good agreement in deep layered lift
interacting with southern moisture (1 to 2 std PWAT) bringing a
soaking rain during the late Monday night to Tuesday Aft period. An
isolated tstm is not out of the question with some weak elevated
instability and strong lift ahead of the cold front...but prob is
quite low. Appears the cold front pushes far enough east late
Tue/Tue night for rain to taper off.

Forecast uncertainty continues for the mid to late week on evolution
of the closed low and how quickly it opens up and move through the
east coast. A more progressive scenario would have high pressure in
control for mid to late week with mainly dry and seasonable
conditions. Meanwhile a less progressive or cutoff scenario would
result in potential for additional waves of low pressure to develop
along the cold front and affect the region mid to late week.
Forecast is currently weighted towards the former scenario based on
ensemble means and operational majority...but the latter
unsettled solution is climatologically plausible.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Canadian high pressure builds in through the weekend.

VFR with northerly winds through the TAF period.

.Outlook for 00Z Monday through Thursday...
.SUN NIGHT-MON...VFR.
.TUE...MVFR w/areas of IFR in the morning. Becoming VFR from West to
East midday.
.WED-THU...VFR.

&&

.MARINE...
Northerly winds will continue across the waters through Sunday
night briefly strengthening late tonight into Sunday morning as
the pressure gradient tightens with strong high pressure building
in from the NW. Gusts may top out 20-25 kt. At the same time,
long period SE swells from distant tropical cyclone Karl will
continue to impact the ocean waters with seas right around 5 ft.
The SCA will remain up through the day Sunday.

SCA conditions likely Monday Night into Tuesday on ocean
waters, and possible all waters, ahead of an approaching frontal
system.

Sub sca conditions likely return for midweek with a weak pressure
gradient and diminishing southerly swells.

&&

.HYDROLOGY...
A frontal system moves through Tuesday with a general 1/2 to 1 inch
of rain likely...with locally higher swaths possible. Hydrologic
impacts are expected to be minor.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Rip Current Risk through Sunday evening for NYZ075-080-
     081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Sunday for ANZ350-353-355.

&&

$$
SYNOPSIS...NV/DW
NEAR TERM...NV/DW
SHORT TERM...DW
LONG TERM...NV
AVIATION...JC
MARINE...NV/DW
HYDROLOGY...NV/DW