401
FXUS61 KOKX 031152
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
752 AM EDT Mon Jun 3 2024

.SYNOPSIS...
A weak disturbance passes offshore early today, with high
pressure then gradually building down from New England into
midweek. High pressure moves out into the Atlantic Wednesday
night. A warm front approaches thereafter and moves within the
region Thursday. The warm front then moves north, leaving the
area with an approaching central area of low pressure for
Friday. The low meanders near the area going into the upcoming
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Forecast remains on track early this morning with just a couple
spotty sprinkles moving through. Otherwise, a dry and mild
start to the day with temperatures in the 60s and lower 70s.

The few lingering sprinkles and showers, mainly along coastal
Long Island, come to an end by mid morning as a weakening
disturbance aloft passes east. Thereafter, drying conditions as
ridging begins to return and a 1020 mb high over Quebec
gradually noses south into midweek and sets up an onshore flow.

Cloud cover should begin to break up, especially away from the
coast, and bring a return to sunshine by early afternoon with the
exiting of the disturbance. With ample sun, temperatures will once
again rise into the low to middle 80s for much of the area. Hints of
instability off to the west this afternoon may be able to instigate
a few pop up showers or thunderstorms with daytime heating, but
coverage looks limited given dry air, lack of significant forcing,
and only marginal instability. Maintained a slight chance (20%)
for this late afternoon activity, but confined to areas from
NYC on west. BUFKIT soundings do indicate DCAPE values approaching
1000 J/kg given the dry low levels and steepening lapse rates,
so not out of the question that any thunderstorm that goes up
could produce an isolated damaging wind gust. Still, severe threat
looks minimal and SPC has maintained the local area in a general
thunder.

Any convection weakens by evening with loss of heating and as
heights begin to recover behind the shortwave begin to ridge a bit
more. Lows tonight will be in the mid 50s to low 60s, or near just
to above normal for early June.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Ridging aloft continues to shift east on Tuesday and Wednesday
with surface high pressure situated off to the north.

Dry on Tuesday with high pressure sliding down the New England coast
keeping fair weather conditions in place. The developing onshore
flow Tuesday will keep coastal locales a bit cooler than recent
days, with highs likely in the low to mid 70s during the
afternoon. Away from this influence, mainly the far interior and
areas west of the Hudson River, lower 80s is where temperatures
top out.

A vigorous shortwave rounding the base of a sprawling upper low
over Central Canada will eject into the Midwest midweek,
spelling an end to the relatively quiet pattern that has been
in place. Rain chances increase Wednesday afternoon and evening
with the approach of an associated warm front from the south and
west. While the bulk of the day appears dry, global ensembles
have trended a bit quicker with this WAA, and will need to continue
to monitor these trends. It`s just as possible however any wet
weather holds off until later Wednesday night. Temperatures on
Wednesday will be held down some by the increasing cloud cover
and persistent onshore flow, with highs in the 70s for most.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Main points

* Heavy showers and thunderstorms looking likely for Wednesday night
  into Thursday. Possibility for mainly minor flooding. See hydro
  section for more details.

* Periodic shower activity for Friday and into upcoming weekend.
  Possible thunderstorms at times as well.

* Temperatures will not depart much from normal values this time of
  year.

Synoptic pattern shows a transition from mid level ridge to a
longwave mid level trough that eventually closes off. The mid level
cutoff low then moves towards the local region towards the end of
the week and into the upcoming weekend. The base of the trough and
its axis potentially get within the local region by Sunday
night. This analysis is from the LREF grand ensemble.

Here is how the forecast changed compared to the previous forecast:

Temperatures no significant changes. Max temperature forecast lower
80s NYC and locations N&W Thursday and Friday. Min temperatures
forecast mid 50s to around 60 for much of area Friday night and
Saturday night, lower 60s for NYC.

POPs trended up Wednesday night, overnight, now into likely NYC and
locations N&W, overnight Wed night into early Thursday AM, 6-12Z
Thursday, likely POPs all forecast region 12-18Z Thursday, just
about entire area 18Z Thursday - 00Z Friday. Otherwise no
significant changes.

Despite marginal elevated instability in the Thursday into Friday
timeframe, there is potential for some low to mid level omega to aid
in vertical lift, so that is why there are higher chances of
thunderstorms and wanted to have higher than slight chance thunder.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Offshore high pressure remains through the TAF period.

Mainly VFR conditions are expected through the TAF period.
A pop-up shower or thunderstorm will be possible for this
afternoon, mainly in the latter half in and around NYC
terminals, KHPN and KSWF. There is a low possibility of MVFR
with any shower or thunderstorm as well as a strong isolated
wind gust. Only currently have the mention of the possibility
of a thunderstorm at KSWF where there is relatively higher
confidence.

Winds overall will be quite light through the TAF period with
wind speeds under 10 kts. Wind direction will be quite variable
into early this morning, followed by more of a sea breeze
circulation for most terminals during the afternoon before
weakening going into early this evening. For tonight, wind
direction becomes variable again. A more east to southeast wind
is expected to develop going into early Tuesday.

    NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Low confidence in wind direction forecast today.

Wind direction may turn out to be more variable for today with
occasional large differences from forecast possible this
afternoon.

OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...

Tuesday: VFR.

Wednesday: VFR during the day. MVFR or lower possible late day
into the night with chances of showers and thunderstorms.

Thursday: MVFR or lower possible in rain showers, possible
thunderstorms afternoon into night.

Friday: MVFR possible at times. A chance of showers with
thunderstorms possible.

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

&&

.MARINE...
Conditions will remain below SCA levels through late week with
seas on the ocean generally 3 ft or less.

&&

.HYDROLOGY...
There are no hydrologic concerns through Wednesday.

With precipitable waters potentially approaching near 2 inches
Wednesday night into Thursday, some showers and especially any
thunderstorms could have heavy downpours. The potentially torrential
rain could cause minor flooding in low lying, urban and poor
drainage areas. With sufficient movement to showers and
thunderstorms, would think much of the flooding potential would be
minor.

&&

.TIDES/COASTAL FLOODING...
Coastal flood statement in effect for South Shore Bays, Southern
Nassau NY 4PM this afternoon to 8PM this evening. Coastal flood
statement in effect for Southern Westchester NY, Southern
Fairfield CT 8PM this evening to 12AM tonight. The indication
here seen in Stevens and ETSS indicates these locations are
touching or slightly exceeding minor coastal flood benchmarks
for this evening high tide.

With the approach of a new moon this week, astronomical levels will
be on the rise. With winds becoming more southerly and eventually
southeasterly, this will allow for increasing surge this week. As a
result, some locations especially across the Western LI Sound
and LI South Shore back bays may see minor coastal flooding,
starting with Monday afternoon`s high tide cycle and becoming
more widespread Tuesday night and Wednesday night.

Stevens guidance shows minor flood benchmarks being approached,
or exceeded by a few tenths for a few spots along southern
Nassau and the Western Sound. Thus, trends will need to be
monitored in subsequent cycles as minor coastal flooding will
become more likely for these areas Tuesday into Wed.

There is a low rip current risk through Tuesday due to low seas
on the ocean and winds mainly 10 kt or less.

&&

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

&&

$$

SYNOPSIS...JM/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JM
AVIATION...JM
MARINE...JM/DR
HYDROLOGY...JM/DR
TIDES/COASTAL FLOODING...