585
FXUS61 KOKX 131448
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1048 AM EDT Thu Jun 13 2024

.SYNOPSIS...
High pressure remains in control today, followed by a cold front
approaching Friday and moving through Friday night. High pressure
returns for the weekend before sliding offshore early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Forecast on track. Temperatures and dewpoints have good
agreement last few hours comparing forecast with observed
values. Slightly increased cloud coverage for the day but still
expect overall mostly sunny conditions.

A semi-zonal upper level pattern will be in place today. A southwest
flow will become more southerly with localized hybrid sea breeze
interaction further east towards afternoon. Look for a good deal of
sunshine with just some scattered cumulus likely at 5 to 8 kft as
indicated by BUFKIT forecast soundings. There will also be some
scattered to broken cirrus throughout the day. A SW flow at 850
mb gets 5kft temperatures climb to about 14 to 16 C. This will
yield warmer temperatures region wide, with the warmer
temperatures muted slightly further east across the CWA due to
sea breeze development during the afternoon. Daytime max
temperatures will be in the 80s for the most part CWA wide.
Expect some middle and upper 80s across the NE NJ metro, with
just some middle and upper 70s across SE coastal communities.
The winds likely get gusty in the 20 to 25 mph range later in
the afternoon for portions of southern Nassau, Queens, and
Brooklyn as an Ambrose jet feature attempts to get going.

For tonight high pressure will begin to weaken and get further
east. Look for partly cloudy to mostly clear skies for the first
half but for the second half late overnight into early Friday
morning, there are expected to be more clouds moving in from
the west. With some low to mid level Q vector convergence noted
more so by the GFS with this not indicated as much with the NAM,
have a slight chance of showers late overnight into early Friday
morning for parts of the southern coastline along NYC and Long
Island. In the mid levels, the models do convey weak positive
vorticity advection on the backside of the mid level ridge
traversing the local region between 2AM and 8AM Friday.

A SW synoptic flow regime should keep temperatures above normal
at night for the first time in awhile as dewpoints inch a touch
higher. Lows should range primarily from the middle 60s to
lower 70s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Even warmer with a subtle climb in humidity as a S to SW flow
increases overall as a cold front approaches from the west. Expect
lots of sunshine through the early afternoon, with clouds increasing
from west to east with the approach of a cold front. Temperatures
are expected to reach the upper 80s to 90 for the NE NJ metro, with
mainly 80s elsewhere, and middle and upper 70s across far eastern
coastal sections. Convection ahead of the cold front is expected to
initiate towards 18 to 20z for the northwestern portions of the CWA,
with the activity moving ESE through the late afternoon and evening.
SPC has placed the area in a marginal to slight risk of severe
thunderstorms, with the slight risk roughly for the western half of
the CWA. The main threat with any storms at this time appears to be
gusty to damaging wind gusts in any stronger storms. Storm mode
appears to be multi-cell clusters with perhaps the storms becoming
more of a broken organized line as it gets closer to the metro
during the evening. MLCAPE values are expected to exceed 1000 J/kg
for far western areas, with bulk shear values in the 35 kt vicinity
as this has the chance to be the first widespread thunderstorm
activity of the season for a good portion of the CWA. A general
weakening trend in any storms is expected as the storms encounter
more of a marine environment as they move across the eastern third
of the CWA.

The showers and storms should slide to the east by midnight for far
eastern sections. A Drier NW flow moves in quickly in the wake of
the FROPA, with noticeably lower humidity into Sat AM with clearing
skies.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Surface high pressure builds in from the NW behind the exiting cold
front on Saturday, centering itself over the area on Sunday as an
upper-level ridge begins to build into the area. This ridge remains
over the Northeast on Monday before amplifying Tuesday into
Wednesday, remaining highly amplified into Thursday.

HEAT! That pretty much sums up the concerns for the long-term
forecast. Our first heat wave of the season could be a possibility
with multiple days expected to reach the mid-90s with upper-90s
possible. The hottest days are expected to be Tuesday through
Thursday. Heat index values are projected to be between 95 and 100
at their peak due to higher dewpoints being advected in from onshore
flow. This onshore flow, however, could lead to subtle relief for
Long Island and parts of coastal Connecticut where winds blowing in
from cooler ocean waters may allow their temperatures to be slightly
cooler than the rest of the CWA. Heat Advisories may need to be
issued as the event nears, if the forecast does not change too much.

850mb warm air advection starts aloft on Monday, but doesn`t really
become anomalously strong until Tuesday. Its important to note that
there is uncertainty with regards to the maximum temperatures. All
global model guidance agrees on a highly-amplified ridge over the
northeast with warm air advection aloft, but they still differ in
magnitude. Expect the forecasted temperatures to change somewhat
until the model guidance comes into better agreement. For now, went
with a blend of NBM deterministic and NBM 50th percentile. Even the
NBM 25th percentile was warmer than the deterministic NBM, so by
blending the two together, it has increased forecasted temperatures
next week.

A few weak shortwaves embedded within the longwave ridge on Sunday
and Monday will help forestall strong heat until Tuesday. The
shortwaves will increase cloud coverage somewhat and prevent the
ridge from amplifying until Tuesday. This will leave temperatures
near normal for the weekend and only slightly above average on
Monday.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
VFR this afternoon. Weak high pressure in the area.

Winds strengthen this afternoon 10-15 kt and become gusty at
around 20 kt for most terminals into early evening in a more
southerly direction. A few at the coast could gust up to 25 kt.
Thursday night, gusts diminish. Winds may hover around the 10 kt
range overnight Thursday into Friday morning.

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

Timing of afternoon/evening gusts may be off by a few hours.

Magnitude of afternoon/evening gusts may be off by a few knots.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Friday: MVFR or lower possible in showers/tstms late afternoon
or evening.

Saturday through Monday: VFR.

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

&&

.MARINE...
A return flow gets established with a south to southwest flow regime
today with 2 ft ocean seas getting closer to 3 ft by this evening.
With an Ambrose jet attempting to get going late today some
occasional small craft gusts cannot be ruled out for the western
ocean and towards the Harbor entrance later this afternoon. Overall
the S to SW flow results in marginal small craft gusts into Friday
ahead of an approaching cold front, especially out on the ocean. The
winds then shift to the NW and N Friday night into Saturday with sub
small craft conditions prevailing through early next week.

&&

.HYDROLOGY...
Showers and thunderstorms are expected to bring a round of brief,
but locally heavy rain late Friday and Friday evening. Rainfall
amounts are expected to average from around a half inch to one inch.
Instantaneous rainfall rates will be rather high, but the storms are
expected to progress along. Therefore impacts will most likely be
limited to minor urban and poor drainage flooding due to the quick
movement of this system, with flash flooding appearing unlikely at
this time.

&&

.TIDES/COASTAL FLOODING...
There remains a moderate rip current risk this afternoon for the
ocean beaches, and a high risk for most ocean beaches Friday.
Eastern Suffolk beaches are expected to have a moderate rip current
risk on Friday.

&&

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

&&

$$

SYNOPSIS...JE/BR
NEAR TERM...JE/JM
SHORT TERM...JE
LONG TERM...BR
AVIATION...IRD
MARINE...JE/BR
HYDROLOGY...JE/BR
TIDES/COASTAL FLOODING...