000
FXUS61 KOKX 171146
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
746 AM EDT Thu Aug 17 2023
.SYNOPSIS...
A stationary front to the south will lift through the area as a
warm front Thursday night. A cold front will move through
Friday afternoon and evening. High pressure will build in for
the weekend, followed by a frontal passage around Tuesday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Stationary front remains just offshore to our south and east
this morning. A few isolated showers, as well as some patchy
mist, developed overnight, and may linger into the morning
hours in a few locales. Otherwise, a dry start to the day under
a mix of sun and clouds. Forecast remains on track.
Into the afternoon, this weak boundary should lift north as a
warm front as an upper trough digs into the Great Lakes. As the
front moves north, expect an increasing S/SW flow, and an
increase in cloud cover. While far from a washout, isolated to
scattered shower activity is possible with the moist, weakly
unstable air mass in place. Temperatures will be near, if not
just below, seasonal normals for the time of year. Most top out
around 80, with low to mid 80s in the urban metro.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
As the one boundary lifts north, a cold front approaches from
the west on the leading edge of the incoming trough.
Coverage of showers increases overnight as the warm front lifts
north and the cold front off to the west begins to approach.
While a few embedded thunderstorms are possible with this
activity, instability is rather low, and not anticipating a
widespread severe concern. Certainly, locally heavy downpours
are possible as PWATs climb to around 2 inches overnight into
Friday. Fortunately, activity looks to move fast enough to limit
flood concern. WPC has a marginal risk for excessive rainfall
nearly regionwide today and Friday, with perhaps some isolated
flash flooding possible.
With increasing shear as the trough and surface front approach,
could see a few strong to severe thunderstorms develop in the
morning hours, though greatest chances look to remain north. SPC
maintained a marginal risk for the region, primarily for
isolated damaging wind gusts. The bulk of the rain comes to an
end in the morning, and the front itself should move through
from west to east by the afternoon, with the flow turning W or
WNW behind it, ushering in a cooler, drier air mass to start the
weekend. Temperatures on Friday will be similar to Thursday,
with highs in the low to mid 80s. Largely followed the
superblend of guidance for this update, with only subtle
adjustments as needed.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Continued dry Saturday through Sunday with rising heights and
warming temps as high pressure builds in at the surface. Large
sprawling cut off high builds over the center of the US Sunday into
the beginning of next week, with h5 heights progged to around 600
dam per the GFS. This hot airmass will battle the northern stream,
with an upper low and associated cold front coming through the
forecast area in late Monday night into early Tuesday morning. Due
to the uncertainty, the NBM was followed closely.
With warming heights, temperatures will be warm on Sunday through
Monday, with highs int the upper 80s to around 90 by Sunday, but
excessive heat is not expected at this time. Temperatures return to
seasonable levels for Tuesday and thereafter.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A weak surface trough will remain stationary just west of the NYC/NJ
metro terminals into the Lower Hud Valley, with a warm front lifting
north today into this evening.
Light E/SE flow tonight into the AM push, increasing from the SE/S
around 10 kt this aft/eve with sea breeze moving well inland.
MVFR/IFR expected through daybreak. There is a great deal of
uncertainty with how low ceilings and vsby get. However, there is a
fair amount of certainty that conditions will be at least MVFR.
Gradual improvement to MVFR then VFR this morning into afternoon.
Isolated to scattered SHRA possible this afternoon, particularly NE
NJ an interior terminals in vicinity of surface trough and sea
breeze boundary. Increasing chances of SHRA and isolated TSRA this
eve/night with warm frontal passage.
The afternoon haze potential forecast is YELLOW, which implies slant
range visibility 4-6SM outside of cloud.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
MVFR/IFR cigs likely for AM push, improving to VFR by afternoon,
however there is a great deal of uncertainty with how low cigs get
this morning. Isolated SHRA potential, however little if any
impacts to cigs and vsby is expected.
Generally S/SE flow around 5 to just under 10 kt for city terminals
for AM and PM pushes, except NE winds possible for KLGA for AM push.
Isolated TSRA possible for all terminals mainly after 10Z
Friday. Added PROB30 for this possibility. MVFR or lower is
possible with
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Thursday night: Chance of showers and thunderstorms with MVFR or
lower possible.
Friday: Chance of mainly AM showers and thunderstorms with MVFR or
lower possible. W winds G20kt in the afternoon.
Saturday-Monday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Increasing S-SW flow will build ocean seas to near 5 feet
tonight, likely remaining elevated into Friday night. SCA was
hoisted for ocean zones beginning 10Z Friday, and continuing
until 6z Sat. It`s possible the elevated seas linger a bit later
into Saturday AM. These diminish through the day Saturday.
Thereafter, winds and seas remain below SCA criteria through at
least Monday.
&&
.HYDROLOGY...
Showers and thunderstorms late today into Friday could produce
heavy downpours that lead to nuisance urban and poor drainage
flooding. Isolated areas of flash flooding are possible.
Thereafter, no hydrologic impacts expected from Wednesday
through next Monday.
&&
.TIDES/COASTAL FLOODING...
For today, there is a low rip current risk for NYC and Nassau
County ocean beaches, with a moderate risk for Suffolk beaches.
For Friday, a high risk of rip current development at all ocean
beaches as offshore seas build to near 5 ft.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM Friday to 2 AM EDT Saturday for
ANZ350-353-355.
&&
$$
SYNOPSIS...JP/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JP
AVIATION...JP
MARINE...JP/DR
HYDROLOGY...JP/DR
TIDES/COASTAL FLOODING...