AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1033 PM EDT THU JUL 21 2016

.SYNOPSIS...
High pressure builds offshore through Friday. A cold front
approaches Friday night and moves through early Saturday. High
pressure returns Saturday night through Sunday. Another cold front
approaches on Monday and passes through the area Monday night.
High pressure builds into the area Tuesday through Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The increase in warmth and humidity starts tonight with SW flow
continuing as high pressure builds offshore.

The weakening MCS activity rotating around the Central US upper
ridge will filter mid and high level clouds into the region
overnight into early Friday.

With onshore flow and warm air advection, lows will trend several
degrees warmer compared to the previous night.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Shortwave and jet streak approach during the day but most forcing
arrives Friday Night into early Saturday. The bulk of it stays
north of the region.

Friday starts out dry but increasing heat and humidity will make
for heat advisory thresholds being met across NYC and much of
Northeast NJ. Rest of region heat indices into the 90s.

A high risk for rip current development at ocean beaches will be
developing Friday morning...and continuing high through the
evening due to southerly wind waves increasing to 3 to 5 ft and a
residual 2 ft se swell.

Showers and thunderstorms become more probable in the afternoon
with increasing instability and at night when the forcing aloft
arrives closer.

Showers and thunderstorms taper off late Friday Night but with
cold front boundary approaching and moving across early Saturday,
a low probability of showers and thunderstorms will remain.

Another hot day Saturday but relatively drier with the westerly
flow. This should allow for more vertical mixing and lower
dewpoints. Still though heat indices with higher actual
temperatures but a little lower dewpoints will be well into the
90s once again for most places.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
High pressure builds into the area Saturday night into Sunday.
Temperatures will be in the upper 80s to lower 90s on Sunday and
Monday with dewpoints in the 60s, but heat indices at this time are
expected to be below 95 degrees.

Low pressure moving through the Great Lakes Monday...will push a
warm front through the area Monday morning followed by a cold front
Monday night. Scattered showers/thunderstorm are possible Monday,
with convection ending early on Tuesday. Dry conditions return as
high pressure builds across the area on Tuesday and remains in
control through Thursday. Temperatures on Tuesday will be in the
upper 80s to lower 90s with dewpoints in the mid 60s to around 70,
allowing heat indices to climb into the mid 90s once again.
Temperatures slowly fall back to near normal towards the end of the
week.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
High pressure remains offshore through Friday with an approaching
frontal system from the Great Lakes late in the forecast period. A
pre frontal trough is expected to develop in the vicinity of the
northeast coast Friday afternoon, with a chance of scattered showers
and thunderstorms.

VFR through the TAF period.

Southwest winds 5 to around 10 KTS expected overnight into early
Friday morning. Southwest winds increase to around 15 KTS during
the morning with gusts 20 to 25 KTS.

.OUTLOOK FOR 00Z Saturday through Tuesday...
.Friday night...MVFR or lower possible in SCT TSRA. SW winds 15-20
KT with 25 KT gusts across NYC and Long Island.
.Saturday through Sunday...VFR.
.Monday and Tuesday...MVFR or lower possible in SCT TSRA.

&&

.MARINE...
Sub SCA conditions overnight under the influence of high
pressure. The high pressure area moves farther offshore, giving an
increase in the pressure gradient for Friday. Winds increase
during the day, with ocean zones and South Shore likely increasing
with gusts to 25-30 kt thresholds for the aft/eve. The increasing
winds will increase fetch with ocean seas building to 5-6 ft for
late Friday afternoon through Friday night. A cold front moves
across early Saturday with conditions returning to below SCA
Saturday.

Below small craft advisory conditions are expected across the area
waters Saturday night through Tuesday.

&&

.HYDROLOGY...
Boundary layer winds increase Friday so thunderstorms Friday
afternoon and evening will be faster moving, mitigating the flood
threat. Still though, some localized minor urban and small stream
flooding will be possible.

No adverse hydrologic impacts are anticipated with scattered
showers and thunderstorms Monday/Monday night.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Heat Advisory from noon Friday to 7 PM EDT Saturday for
     NYZ072>075-176-178.
     High Rip Current Risk from 10 AM EDT Friday through Friday
     evening for NYZ075-080-081-178-179.
NJ...Heat Advisory from noon to 7 PM EDT Friday for NJZ004-006-
     103>108.
MARINE...Small Craft Advisory from noon Friday to 6 AM EDT Saturday for
     ANZ350-353-355.
     Small Craft Advisory from noon to 8 PM EDT Friday for ANZ345.

&&

$$
SYNOPSIS...FIG/JM