786
FXUS61 KOKX 180525
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
125 AM EDT Tue Jun 18 2024

.SYNOPSIS...
High pressure stretching in from the western Atlantic remains in
control through late this week. A cold front stalls north of
the area late Friday and Saturday. Another cold front will
gradually draw closer late in the weekend and early next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Increased clouds but it is a thin cirrus without much effect on
surface temperatures. Expecting partly cloudy conditions for
most areas through the remainder of the night. The radiational
cooling is already being offset by a warm southerly wind staying
up within the boundary layer. Temperature and dewpoint forecast
on track.

Upper level ridging builds with surface high pressure to our
east and southwest keeping rain out of the picture tonight. A
return S-SW flow will keep somewhat muggy conditions in place as
dewpoints remain in the 60s. Overnight lows still expected to be
in the mid 60s for most areas, ranging into the low 70s in the
city.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
A strong ridge remains in place Tuesday through Wednesday with a
500mb high centered near or over us and surface high pressure
offshore to our east. This should be enough to keep any shower
activity out of the area during this period.

Models seems to have settled on 850mb temperatures of 17-19C for
both days, with the higher values generally across the northern
zones. With the winds arriving from over the cool waters, expecting
highs mostly in the mid 80s for most of LI and coastal CT both days.
 upper 80s/around 90 for NYC and interior CT, and lower
to middle 90s elsewhere.

Regarding surface dewpoints, at least a little daytime mixing
out/lowering is still anticipated for areas not under a S wind flow
as models continue to forecast sufficiently dry dewpoints at the top
of the mixed layer. Additionally, there will be antecedent dry soils
with the recent lack of rain and there will be no cold front or
significant trough nearby to provide low level moisture convergence.
And now that we`re within days 2-3 of the forecast period,
deterministic NBM surface dewpoints have lowered nearer towards
expectations - away from its high bias seen over the past several
weeks for longer lead times.

No changes to heat headlines needed for this period. Heat indices
within the advised area are expected to be mostly in the 95-100
range.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
**Key Points**

* The heat wave for interior locations (especially north west) is
  expected to continue in the long term period. The heat should
  continue through at least Saturday, and potentially into Sunday
  and a portion of Monday.

* The combination of the heat and humidity will produce heat index
  values of 95 to potentially up to 102 during this time frame away
  from the coast. The most impactful effects from the heat will be
  felt further away from the cooler effects of the ocean,
  particularly across north and western interior sections (including
  interior NE New Jersey), and northwestern portions of Southern
  Connecticut.

* Not much relief at night with warm and humid conditions as
  overnight lows will be in the upper 60s to the middle 70s, with
  dew points remaining well into the 60s.

The long term period begins with the region in the center of a
anomalous 595+ dm ridge, with a trough along the West Coast and
portions of the intermountain west. The global guidance consensus
points towards a gradual breakdown of the ridge over time during the
weekend and into early next week.

Look for an increasing chance of showers and storms throughout the
weekend and into early next week. There will be the chance of
isolated, or a few widely scattered storms late Friday, but this may
stay just north of the area. A slight chance of showers and storms
looks to be the case on Saturday, but much if not all of the day
will be dry with the heat continuing along with high humidity.
Towards late Sunday, and especially into Monday is when the more
noticeable height falls are expected to take place as the cold front
which stalls to our north and northwest late this week finally makes
more of a push towards the area. This will eventually break the
heat, but there remains questions as to exactly when the heat breaks
and showers and storms become more widespread later in the period.
The latest guidance consensus is pointing towards Late Mon / early
Tue being the time when the heat breaks, followed by cooler and less
humid conditions towards Tue of next week.

It is important to exercise caution with the intense heat and high
humidity, thus it is important to take precautions to protect one`s
health, particularly those without effective cooling and/or adequate
hydration.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
High pressure remains in place offshore through the TAF period.

VFR with a S-SW flow through the TAF period.

S-SW flow under 10 kt overnight expected into early Tuesday and
then increase to near 10 kt Tuesday afternoon into early
Tuesday evening with gusts near 20 kt. Not every terminal is
expected to have gusts.

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

Start and end timing of gusts could be a few hours off from the
TAF.

OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...

Tuesday night: VFR.

Wednesday through Saturday: Mainly VFR. S-SW wind gusts 15-20
kt afternoon into early evening Wednesday and Thursday.

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

&&

.MARINE...
With high pressure largely in control, sub Small Craft Advisory
conditions are expected to prevail through at least the middle
of this week. There may however be occasional gusts up to
around 25kt into the overnight on the ocean waters west of Fire
Island Inlet.

A S to SW flow will continue with high pressure anchored to the east
and south of the coastal waters towards later in the week. On
the ocean, seas may touch 4 ft at times with gusts up to 20 kt
for Thursday and Friday, but sub small craft conditions are
expected to continue throughout the week and into the start of
the weekend.

&&

.HYDROLOGY...
There are no hydrologic concerns through at least the early
portion of the upcoming weekend. A cold front will bring a chance
of showers and t-storms late in the weekend and early next
week, but it remains too soon to determine whether there will be
any hydrologic impacts. Any impacts would likely be very
localized and more of the minor urban type.

&&

.TIDES/COASTAL FLOODING...
There remains a moderate rip current risk at the ocean beaches
Tuesday and Wednesday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from noon today to 8 PM EDT Wednesday for CTZ005-
     006.
NY...Heat Advisory from noon today to 8 PM EDT Wednesday for
     NYZ067>070.
NJ...Heat Advisory from noon today to 8 PM EDT Wednesday for NJZ002-
     004-006-103>108.
MARINE...None.

&&

$$

SYNOPSIS...JC
NEAR TERM...JC/JE/JM
SHORT TERM...JC
LONG TERM...JE
AVIATION...JT
MARINE...JC/JE
HYDROLOGY...JC/JE
TIDES/COASTAL FLOODING...