000
FXUS61 KOKX 071151
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
751 AM EDT Wed Jun 7 2023
.SYNOPSIS...
Low pressure will weaken over the Canadian Maritimes today and
then drifts back to the west along the New England coast Thursday.
A surface trough dropping south on the backside of the low will
pass through the forecast area later this afternoon into this
evening. A series of troughs will then move across the area
Thursday into Friday. Weak high pressure builds in Friday night
into Saturday and moves offshore Saturday night into Sunday. A
frontal system impacts the area Monday and Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Minor changes made with this update to account for latest
observations and trends.
A cutoff upper low over the Canadian Maritimes will gradually
weaken over the next couple of days while working west across
northern New England. The surface reflection this morning is
around a 992 mb low near Nova Scotia. This system is also
aiding the southward push of smoke from wildfires across eastern
Canada with another significant push per the latest RAP/HRRR
guidance for this afternoon into tonight.
A surface trough rotating southward on the backside of the low
will move across the area late this afternoon into early this
evening. CAMs continue to show any showers with the trough to be
across southeast CT and eastern LI. Otherwise, looking for a
mainly dry day with mostly sunny skies to start, but filling
in with clouds due to steep mid level lapse rates and deep
cyclonic flow. Any shower activity ends early this evening.
NW winds will back around to a more westerly direction this
afternoon with possible seabreeze development along the south
shore of LI. Light northerly winds follow behind the trough
tonight.
It will be another seasonably warm day with highs mainly in the
70s, but possibly as high as 80 across metro NJ. Lows tonight
will range from the upper 40s inland, to the upper 50s across
the NYC metro. This is slightly below normal with some cooler
air wrapping around behind the low and into the areas.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The upper low becomes nearly stationary across northern New
England during this time in what remains a highly amplified and
blocked flow across North America. The upper trough axis rotates
southeast and across the area on Friday. This will result in
increasing chances of showers each afternoon, especially Friday
afternoon with the upper trough axis overhead. Airmass is fairly
stable but there could be isolated thunderstorms Friday. Rainfall
amounts during this time look to be light with less than a
quarter inch forecast.
Clouds will also become more prevalent with the placement of the
upper flow and moisture being wrapped around the large upper
vortex. This will result in a gradual cool down into Friday.
Highs on Friday will struggle to get much higher than the upper
60s to around 70. Leaned toward the cooler MOS guidance versus
the NBM.
Hires guidance also pointing to smoke concerns lingering into
Thursday, but confidence is not high.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Upper closed low pressure remains over Northeast Friday
night and weakens into a trough, while the surface low dissipates
into Saturday. The longwave trough remains across eastern Canada and
another shortwave will move into the Great Lakes region Sunday,
developing into another closed low that induces a surface low late
Sunday night into Monday morning over the central Great Lakes
region. The attendant warm and cold fronts will slowly
approach the area through Monday night and then move
through Tuesday. The now stacked low will remain over the
Great Lakes region Monday through Monday night, then head
northeast and pass well north and west of the forecast area into
Wednesday.
Generally unsettled weather will impact the area
through much of the long term with a chance of showers, and
thunderstorms Friday night into Saturday. Saturday night into Sunday
look to be dry with weak high pressure over the area. The surface
low and cold front impacts the area later Monday into Tuesday with
chances for showers and thunderstorms once again, mainly during the
afternoon and evening hours.
Temperatures will be below seasonal levels Friday, and
return to more seasonal levels Saturday into the beginning of next
week.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Any reduced visibilities due to smoke should continue to
improve as the morning continues, through about 15Z. VFR
conditions are then expected until this afternoon (after 18Z)
when another round of smoke is expected to move in from the NW.
However, there is a good deal of uncertainty and the forecast
may be off by +/- a few hours.
NW winds continue to diminish through around daybreak,
increasing thereafter. A shift to the W is expected in the afternoon
at speeds of 10 to 15 kt. Coastal terminals like KJFK, KISP, KBDR
and KGON shift to the W to SW late in the day. However,
there is more uncertainty with this wind shift at KJFK and KBDR.
There is a slight chance for showers this afternoon and evening,
but mainly affecting KGON. Brief MVFR conditions are possible
with these showers, outside of those caused by smoke.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
The afternoon haze potential forecast is YELLOW, which implies slant
range visibility 4-6SM outside of cloud.
Visibilities will continue to improve through 15Z, likely
lowering again after 18Z today. Visibilities could be reduced
to as low as 3 SM at times in smoke with amendments possible.
The smoke could limit slant range visibilities to 3-6 SM as
well.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday through Friday: Mainly VFR. Chance of afternoon and
early evening showers both days.
Saturday: Mainly VFR. Chance of MVFR conditions late in shra or
tsra, mainly for northern terminals.
Sunday: Mainly VFR. Chance of MVFR conditions towards evening and at
night in shra.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and seas likely remain below SCA levels through the
upcoming weekend with a relatively weak pressure gradient in
place. Low pressure moves away from the waters Friday night
into Saturday as weak high pressure builds in for Saturday and
then east on Sunday.
&&
.HYDROLOGY...
No hydrologic impacts expected through the beginning of next week.
&&
.TIDES/COASTAL FLOODING...
Water levels continue to gradually fall in conjunction with
astronomical tides. In addition, an easterly swell from low
pressure over the Canadian Maritimes will subside. That being
the case, it`s still possible for the high tide cycles Thursday
and Friday night to get close to minor coastal flood benchmarks
across the south shore back bays of Nassau. A statement is
possible, but confidence is not high enough at this time to
issue.
There is a low risk for the development of rip currents at the
ocean beaches today and Thursday due to a diminishing swell and
weak winds.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JP
AVIATION...JP
MARINE...JP/DW
HYDROLOGY...JP/DW
TIDES/COASTAL FLOODING...