Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 272319

Area Forecast Discussion
National Weather Service New York NY
719 PM EDT SAT AUG 27 2016

High pressure builds across the Tri-state area for this weekend.
A cold front will then approach the area Sunday night and slowly
move through on Monday. High pressure follows for Tuesday.
Another cold front moves through late Wednesday into Wednesday
night with high pressure for the end of the week.


The forecast is on track. Made only minor adjustments to hourly
dewpoints, temperatures and winds based on the latest trends.

Deep layered ridging will allow for tranquil...dry and seasonably
cool conditions tonight. Lows generally in the 60s...lower 70s for
nyc/nj metro...and some upper 50s across far outlying rural areas
with good radiational cooling.


Upper ridging flattens on Sunday...allowing a shortwave over the
northern plains today to slide towards the northeast US Sunday night.
At the surface...high pressure overhead early Sunday gradually
slides offshore...allowing a weakening cold front to approach
Sunday night and slowly cross on Monday.

Mostly sunny and dry conditions expected on Sunday...with light e/se
flow in the morning veering to the s/se. A canadian maritime airmass
will limit temps to slightly above seasonable levels at the coast
in the lower 80s...while deeper mixing for nyc/nj metro and
particularly NW interior should have temps in the to mid to upper
80s once again.

A moderate risk for rip current development exists on Sunday as 3
ft at 8 sec period swells build into the waters with minimal se/s
wind waves. There is a low potential for the risk to become high
late in the day if 2 ft 15+ second se swells begin to work into
the water from Gaston. With WNA exhibiting a quick bias with
bringing in swells this summer...and GFDL guidance slower to bring
in these swells...will hold to a moderate risk for Sunday.

Lagging forcing and weak elevated instability should limit
convective activity with the approaching cold front. Increasing
high and mid clouds expected...with an isolated shower or sprinkle
possible to survive into the region late Sunday night into Monday
morning. Cold front appears to only slowly sag through the area
Monday. Instability builds late Monday morning into Monday
afternoon with shortwave energy nearing...but downslope subsidence
and mid-level drying will likely be limiting factors for
convection. So only appears an isolated shra/tsra threat exists
with frontal passage...likely decreasing from nw to se during the
afternoon. Strong winds gusts would be main threat with any
thunderstorms based on drying low/mid levels.

Very warm temps expected on Monday with only gradual caa...downslope
flow and deep mixing...allowing temps to rise into the upper 80s to
lower 90s for much of the coastal plain...mid to upper 80s for nw

High risk for rip current development possible by Monday as long
period se swells from Gaston could build to 3 to 4 ft. If this
occurs...breaking surf in the 3 to 5 ft range could be expected
as well.


High pressure builds behind the departing cold front Monday night
into Tuesday before shifting offshore Tuesday night. This will keep
the region dry with temperatures around 5 degrees above normal.

A cold front approaches on Wednesday and passes during the late
day/nighttime period. Isolated to scattered showers and
thunderstorms are forecast during the period with the best overall
chance appearing to be during Wednesday night. There is a chance
that the cold front is still close enough, coupled with synoptic
lift from a jet streak aloft, for a chance of morning showers on
Thursday. For now, will go with slight chc pops east of the city
Thursday morning. Drying conditions otherwise through Saturday as
high pressure builds in behind the front. High temperatures Thursday
through Saturday will be fairly close to normal, and dewpoints all 3
days will allow for relatively comfortable conditions.

The threat for rough surf and high risk for rip current
development could continue mid to late week if se swells from
Gaston continue to affect the waters.


VFR as high pressure builds over the terminals. Few clouds to
contend with through the forecast period.

Winds should back more SE tonight and diminish to around 5 kt at
the NYC terminals, and go light/variable elsewhere. Expect sea
breeze onset/direction/speed late morning or early afternoon on
Sunday to be similar to that of earlier today.

.Outlook for 00Z Monday through Thursday...
.Sunday night...VFR.
.Monday...Mainly VFR. An isolated afternoon shower or tstm
.Wednesday...Mainly VFR. An isolated afternoon shower or tstm
.Wednesday night...Scattered showers/tstms with MVFR or lower
conditions possible.
.Thursday...Mainly VFR. An isolated morning shower or tstm


Seas will slowly build into early next week in response to long
period swells being generated by distant Tropical Cyclone Gaston.
Refer to advisories from the NHC for latest forecast information.
Whether seas build to marginal sca levels Mon into Mon night will
be based on strengthening of Gaston.

For the rest of the forecast period, winds appear to remain below
advisory criteria, although they will increase during Wednesday
ahead of an approaching weak cold front. Seas will continue to
slowly build in response to long period swells being generated by
distant Tropical Cyclone Gaston. 5+ FT seas could move into to
the ocean waters as early as Monday night, and potentially linger
through the rest of the forecast period.


No significant widespread precipitation is expected through the
forecast period.




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