839
FXUS61 KOKX 040626
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
226 AM EDT Tue Jun 4 2024

.SYNOPSIS...
High pressure builds southward from coastal New England into
midweek before shifting farther out into the Atlantic thereafter.
A series of frontal system then approaches from the west Thursday
through next weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
High pressure building southward from Canadian Maritimes into
Northern New England. The local region is on the southern
periphery of the high with a resulting more onshore easterly
wind.

Some low clouds and fog have developed along parts of Long
Island and Southern Connecticut. Some of the fog, particularly
across parts of Central Suffolk County is locally dense where
visibilities are less than 1 mile.

General range of low temperatures going into daybreak, upper 50s
to upper 60s.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
High pressure makes its way from Northern New England in the
morning to eventually south of Cape Cod early in the evening.

Morning low clouds expected to scatter out with fog burning off
with diurnal heating. A mostly sunny day is expected for most
locations but some low clouds may linger south of Long Island in
the afternoon.

The synoptic flow will be more southeast today, making for a
much more marine influence on the low level environment.
Temperatures gradient will be seen today from coastal
locations where high temperatures are expected to stay in the
70s to low to mid 80s across the interior.

For tonight, high pressure will slowly move farther out into the
Atlantic. Onshore flow will continue but will become more
southerly. Min temperatures are not expected to decrease much,
with a range only from the upper 50s to lower 60s. The increase
in clouds and more in the way of fog development is expected to
limit radiational cooling.

Regarding the fog and low clouds, the more southeast flow will
enable this low level moisture to linger into a part of the day
Wednesday. Current forecast does not indicate fog for latter
half of the morning, but it will be possible. Otherwise, high
pressure will continue drifting out into the Atlantic. Across
the local region, a warm front will be drawing closer from the
south and west.

The southerly winds continue Wednesday but with more clouds and
potentially some showers, cooler temperatures are expected
compared to the previous day. Interior areas have high
temperatures forecast in the lower 80s with the rest of the
forecast region staying in the 70s. In addition to the chance
for showers, there will be a slight chance of thunderstorms as
well. This will be mainly confined to the westernmost parts of
the region, NYC, and locations north and west, which will be
relatively closer to the approaching warm front.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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 /06Z TUESDAY THROUGH SATURDAY/...
High pressure along the New England coast strengthens overnight
and builds into the area Tuesday morning. The center of the
high remains offshore of Cape Cod through Tuesday evening.

Mainly VFR. Chance for low stratus or fog to develop along some
of the coastal terminals into early Tuesday morning and lower
cigs and vsbys to IFR/LIFR. Already seeing this develop just
east of KISP, but low confidence on just how expansive this
area becomes tonight, so maintained a TEMPO here thru 12Z.
Better chance of more widespread coastal cig and vsby
restrictions Tuesday night into Wednesday morning with the
persistent onshore flow. Introduced IFR cigs after 6Z Wed at the
city terminals to highlight this.

The flow is light and variable at most locations, and winds
remain light until later this morning as east flow develops.
Winds then veer to the SE on Tuesday, speeds 10 kt or less.

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

Possible brief IFR/LIFR into early this morning at KJFK.

Low confidence on timing of sub VFR conditions Tuesday night
into Wednesday morning and this may be off by several hours.

OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...

Late Tuesday night: Becoming IFR or lower with stratus, mist,
and potential fog developing.

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 showers and thunderstorms,
mainly during the daytime hours.

Friday: Chance of MVFR with showers and possible thunderstorms.

Saturday: Chance of MVFR in showers.

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

&&

.MARINE...
Conditions will continue to remain well below SCA levels
through Wednesday with a weak pressure gradient in place.

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...
Guidance all points to statement level events for the next few
evenings as tides increase astronomically. Most locations need a
1/2 to a 1 foot to reach minor coastal flood benchmarks. The
existing background anomaly looks to be sufficient enough to get
some of the more vulnerable locations across western LI Sound
and the south shore bays of LI right around these levels. A few
spots may also go 1 to 2 tenths above.

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. This could lead to a bit more coverage as the week
hoes on.

There is a low rip current risk through Wednesday 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...BC
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...JM
AVIATION...DR/MET
MARINE...BC/JM/MET
HYDROLOGY...BC/JM
TIDES/COASTAL FLOODING...