Area Forecast Discussion
Issued by NWS Upton, NY

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323
FXUS61 KOKX 142046
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
446 PM EDT Tue Aug 14 2018

.SYNOPSIS...
Low pressure will pass to the north through tonight, followed by
weak high pressure on Thursday. A warm front will then approach
and lift through early Friday, followed by a cool front Friday
night into Saturday. The front will then settle just offshore
this weekend as weak low pressure rides along it. High pressure
will briefly return on Monday before another frontal system
approaches from the Plains states.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Scattered showers and thunderstorms will continue this
afternoon, some producing moderate to heavy rainfall. Some areas
will see multiple rounds of rain as the low pressure system
producing these showers/storms progresses eastward overnight.
Showers and storms will diminish overnight, especially with lack
of diurnal heating. Breaks in the clouds overnight could lead
to areas of fog with generally light winds and plentiful
moisture as temperatures fall into the mid 60s north and west to
low 70s across Long Island, NYC and along the coast.

There is a moderate risk for rip current this afternoon.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
Models continue to be in good agreement with the 500mb low will
push east of the forecast area Wednesday. Drier air will
continue to filter in behind this system as dewpoints will be
dropping into the 60s. With high pressure ridging Wednesday into
Wednesday night, expect mostly clear to partly cloudy skies.
Forecast 850mb temps of 16C-17C combined with a westerly flow
will result in max temps in the upper 80s to low 90s across most
spots. With the lower dewpoints, expect heat indices just a
degree or two higher than the actual temperature. Isolated 95
degree heat index values could occur in the city and immediate
surrounding suburbs, but not enough coverage for heat advisory
consideration.

Ridging aloft will begin to break down Thursday with max
temperatures a degree or two warmer. This could result in heat
indices of low to mid 90s in and around the city. Minimum
temperatures will remain in the low to mid 70s for most areas
outside of northwestern counties.

There is a moderate risk of rip current development on
Wednesday.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
The ridge aloft will continue to break down and push offshore
Thursday night in response to a shortwave advancing across the Great
Lakes. As the associated surface low tracks across the lakes on
Friday, a warm front will lift north of the region early in the day,
followed by a cold frontal passage late Friday night into Saturday
morning. Shower and thunderstorm chances will increase through the
day, with heavy rain possible at times as precipitable water values
again increase to around 2 inches.

The front then settles just offshore during the day on Saturday.
With energy lingering in the upper trough, this will result in at
least the potential for unsettled weather to continue through the
weekend. In addition, there are some indications that a shortwave
over the Midwest develops a surface reflection as it emerges off the
Mid Atlantic coast during the day on Sunday. At this point it
appears that the bulk of the precipitation would remain south of the
region late Sunday into Monday as that low rides northeastward along
the old frontal boundary. Ridging then briefly builds back into the
region during the day on Monday ahead of the next frontal system
tracking eastward from the Plains.

Temperatures on Friday and Saturday will continue to run several
degrees above normal before falling back to near normal for the
remainder of the long term period. With highs in the upper 80s to
around 90 across much of the region on Friday and plenty of
humidity, heat indices could rise into the mid to upper 90s across
much of northeast New Jersey, New York City, and Long Island.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
An upper level low will approach and move across the region
tonight. Weak high pressure will build into the region on
Wednesday.

Mainly VFR for the remainder of the TAF period, except MVFR or
even IFR conditions may develop in areas of showers and/or
thunderstorms. Any of these showers will be capable of
producing locally heavy rainfall along with gusty/erratic winds.
The best chance for showers and thunderstorms will be through
about 00z.

S-SW flow around 10 kt with a few gusts 15-18kt at the NYC
metros and KISP today. Winds become westerly tonight behind any
storms, with VFR re-developing everywhere.

     NY Metro Enhanced Aviation Weather Support...

Detailed information, including hourly TAF wind component fcsts,
can be found at: http:/www.weather.gov/zny/n90

KJFK TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

KLGA TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

KEWR TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

KTEB TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

KHPN TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

KISP TAF Comments: Showers or thunderstorms may briefly lower
conditions to IFR.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
.Wednesday afternoon-Thursday...Mainly VFR.
.Friday...MVFR or lower conditions possible in late day/evening
showers/tstms from the NYC metros north/west.
.Saturday and Sunday...sub-VFR in showers and thunderstorms.

&&

.MARINE...
Winds and seas will remain below SCA levels this afternoon,
although any thunderstorms that develop could produce locally
hazardous conditions. A brief period of increasing southwesterly
flow tonight into early Wednesday could produce ocean waves
close to 5 ft further offshore, but expect gusts to remain below
25 kts.

Weak high pressure builds Wednesday night through Thursday night
with relatively tranquil winds and seas. Southerly winds
increase Friday night ahead of low pressure and a cold front. At
this time, winds and seas are expected to remain below SCA
thresholds.

&&

.HYDROLOGY...
Rain showers and thunderstorms will taper off overnight as low
pressure shifts east. Dry conditions on Wednesday and Thursday
will allow a bit of a reprieve, but an approaching frontal
system could produce showers/tstms with heavy rain Friday
afternoon and evening. Deep layer SW flow nearly parallel to the
approaching frontal boundary will increase moisture over the
region with PWATS expected to reach over 2 inches. There is
potential for heavy rain with individual cells and also training
of cells, mainly from the NYC metro area north/west.

&&

.TIDES/COASTAL FLOODING...
A coastal flood statement continues for tidal locations along
southern Nassau and southern Queens, along the south shore back
bays. Expect astronomical high tide levels will near minor
flooding tonight.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off
the air for an extended period of time.

&&

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

&&

$$
SYNOPSIS...FEB/99
NEAR TERM...99
SHORT TERM...99
LONG TERM...FEB
AVIATION...BC
MARINE...FEB/99
HYDROLOGY...FEB/99
TIDES/COASTAL FLOODING...
EQUIPMENT...



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