Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 191435
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1035 AM EDT Sat Aug 19 2017

.SYNOPSIS...
One cold front will pass east of Long Island this morning, while
another passes through tonight. High pressure will follow from
Sunday through Tuesday. A frontal system will move across from
Wednesday into Wednesday night, followed again by high pressure.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Shortwave trough aloft over the Great Lakes this morning will
pivot toward the region late today.

A weak surface trough will linger today, with a cold front
approaching from the west for tonight.

A much drier air mass in the low/mid levels will advect/mix down
today.

With shortwave energy still well west and mid-level warming,
forcing and instability will be limited today. Would mainly
expect some diurnal Cu along and north of afternoon surface sea
breeze boundaries. The mostly sunny conditions and warm temps
aloft will allow temps to quickly rise well into the 80s
today, around 90 NYC/NJ metro. Heat indices will run close to
air temperatures.

Residual southerly swells of 3-4 ft @ 6-7 sec period this
morning favor a high rip current risk for the eastern Long
Island ocean beaches, and a moderate risk farther west. These
swells will continue to slowly subside into this evening.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
Vigorous shortwave trough approaches this evening and crosses the
region tonight. At the surface, a weak cold front crosses the region
this evening. High-res models indicating some organized convection
developing/tracking across central PA/NY late this afternoon along
this front, but expectation is that this activity quickly weakens as
it approaches and crosses into the NW hills this evening due to lack
of instability. Elsewhere, a low chance for an isolated shower
overnight with shortwave/frontal passage.

Zonal upper flow ensues for Sun into Mon. At the surface...high
pressure builds in from the west Sunday into Sunday Night, and then
gradually translates to the south and southeast Sunday night. The
result will be a sunny, comfortably dry, and seasonably warm day on
Sunday.

As the high sinks south and east, heat and humidity will build
build into the region Monday into Tuesday. Highs will generally be
well into the 80s to lower 90s on Monday, and possibly lower to mid
90s for Tuesday.

Models are indicating potential for isolated diurnal convection on
Tuesday as instability increases and convectively induced vort
energy rotates around the upper ridge. Low predictability at this
point.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Decent model agreement with shortwave energy digging into the
Great lakes Tue into Tue Night and then towards the NE US on
Wed. An associated frontal system will bring the next chance for
organized shower and tstm activity late Tue into Wed.

A significant cool down then looks to follow for the end of the
week. The models have been very consistent with this signal,
although the exact magnitude of the cold airmass remains in
question. It would not be totally surprising to see some lows in
the furthest outlying areas touch the upr 40s next weekend.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
A secondary cold front will move across the region tonight,
perhaps bringing an isolated shower to KSWF. This will be
followed by high pressure.

VFR through the TAF period.

W-NW flow under 10 kt will continue this morning before winds
back to the SW this afternoon. A few gusts to around 15kt are
possible at the city terminals late this afternoon into early
evening. Winds subside again tonight, becoming variable in
direction but overall exhibiting a west to southwest flow for
city and coastal terminals.

.OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.Sunday-Monday night...VFR.
.Tuesday-Tuesday night...A chance of showers and thunderstorms
with MVFR or lower conditions possible,otherwise VFR. SW gusts
to 15-20 kt late afternoon and at night.
.Wednesday...A chance of showers and thunderstorms with MVFR
possible. SW gusts 15-20 kt.

&&

.MARINE...
SCA has been cancelled as ocean season continue to subside.

Winds and seas will increase ahead of a cold frontal passage
late Tuesday into Wednesday. Ocean seas may reach advy levels
Tuesday night, and continue in southerly swells into Wed night.

&&

.HYDROLOGY...
Impacts from potential showers and thunderstorms Tuesday into
Wednesday are uncertain at this point.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Rip Current Risk until 8 PM EDT this evening for NYZ080-
     081.
NJ...None.
MARINE...None.

&&

$$
SYNOPSIS...Goodman/NV
NEAR TERM...Goodman/NV
SHORT TERM...NV
LONG TERM...JMC/NV
AVIATION...FEB/JM
MARINE...Goodman/NV
HYDROLOGY...NV



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