Area Forecast Discussion
Issued by NWS Upton, NY

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385
FXUS61 KOKX 032346
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
746 PM EDT Mon Jun 3 2024

.SYNOPSIS...
High pressure gradually builds down from New England through
Wednesday, then moves into the Atlantic Wednesday night. A series of
frontal system then approaches from the west Thursday through next
weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Only made minor changes to hourly temperatures, dew points, and
winds, for the current conditions and trends into late this
evening.

High pressure builds into the area from the north tonight. A
weak SE-E flow is expected later tonight. Some of the guidance
is hinting at some stratus moving into the area off the ocean
waters, mainly along the coast. Not sure how much, if any cloud
cover we see. It may be hard to get the clouds with the high
building in from the south. Looks like the better chance will be
Tuesday night. Lows tonight will range from the middle 50s to
middle 60s.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
Ridging aloft continues to shift east on Tuesday and Wednesday
with surface high pressure situated off to the north.

Tuesday will be dry with high pressure remaining off the New
England coast. An onshore flow 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.

Conditions remain dry Tuesday night, however with the second night
of onshore flow, expect a better chance of stratus and/or fog to
develop. Lows will be in the 50s and lower 60s.

High pressure starts to shift eastward Wednesday morning.
Meanwhile, a vigorous shortwave rounding the base of a large
upper low over Central Canada will move into the Midwest. This
will bring 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 to near 80 for most.

&&

.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 /00Z TUESDAY THROUGH SATURDAY/...
High pressure along the New England coast strengthens tonight
and builds into the area by Tuesday morning. The center of the
high will remain offshore of Cape Cod through Tuesday evening.

VFR. There is a chance that shallow low-level moisture moves in
from the east overnight with the possibility of a short period
of IFR/LIFR ceilings at the coastal terminals. However,
confidence remains low and plan to keep out of the forecast at
this time.

A weak S to SE flow remains into early this evening as sea
breezes weaken and end. Winds likely become light and variable
for a few hours before a light east flow develops late/toward
Tuesday morning. Winds will then veer to the ESE during Tuesday.

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

Low confidence of brief IFR/LIFR late tonight/early Tuesday
morning at KJFK.


OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...

Tuesday night: VFR. Chance of IFR/LIFR in low clouds and fog
late.

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 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...
The high tide cycle along the south shore bays has passed and
no flooding was observed. The coastal flood statement has been
cancelled for Southern Nassau. With high tides in the western
Sound later this evening, the coastal flood statement remains in
effect for Southern Westchester NY, Southern Fairfield CT until
12AM tonight.

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.

&&

$$