326
FXUS61 KOKX 212044
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
444 PM EDT Sat Sep 21 2024

.SYNOPSIS...
Offshore low pressure continues to slowly depart to the southeast
tonight through Sunday. Meanwhile, high pressure noses in from the
northeast and remains in control through at least Tuesday. A
frontal system may then approach on Wednesday and move across on
Thursday, High pressure may slowly return on Friday and
Saturday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Offshore low pressure is now centered about 300nm southeast of the
area. The low will continue to slowly depart to the southeast
tonight, while high pressure centered well to our northeast noses
into the area.

Similar to the past few days, showers to the east associated with
the low have had a hard time making it to our area. Kept PoPs
similar to the last forecast. Continue slight chance to chance
through the afternoon for most of far eastern LI and CT,
lowering to slight chance for the evening and early overnight.
Did bump up to likely for the next few hours right along the
eastern New London border where steady returns can be seen
currently. Some precipitation may make it farther west, but this
will likely be just sprinkles and not measurable.

As the pressure gradient slowly slackens over the area tonight,
winds will lower a bit. However, can still expect 10 to 15 mph
sustained winds, with gusts up to 20 mph for far eastern LI and CT.
Given the elevated winds, stuck with the NBM for lows tonight. Not
expecting good radiational cooling conditions.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
High pressure continues to build in on Sunday and will remain in
control through at least Tuesday. Aloft, heights rise on Sunday as
an upper level ridge builds in. The ridge axis will pass overhead
early Monday.

This pattern will bring dry conditions to end the weekend and start
next week. It will also bring a slight cooling trend. Highs will be
right around normal on Sunday and then likely just below normal on
Monday. Stuck with NBM for the most part for temperatures. Blended
some MOS guidance and the NBM 10th percentile across the northern
interior for Sunday night where winds will be lighter and dewpoints
a bit lower.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Points:

* Dry into daytime Tuesday.

* Possible showers Tue night through Thu night with an approaching
  frontal system.

* Uncertainty as to whether shower chances may continue into Fri or
  Sat.

* Temperatures near to slightly below normal from Mon-Thu, with
  moderation to slightly above normal Friday and Saturday.

Forecast mostly follows NBM, but with somewhat lower PoP and sky
cover until the current dry-begets-dry pattern truly shows signs of
breaking. High pressure nosing down from the northeast on Mon should
hang on into at least Tue, then start slowly introducing PoP to
areas W of NYC Tue night, also to the NYC metro area and western
Long Island/CT daytime Wed, and throughout Wed night/Thu.

Model disagreement remains especially from that point on as to
whether the frontal system will even clear the area on Fri with high
pressure building from the N per 12Z GFS, or if low pressure will
develop nearby and then move slowly away per 00Z ECMWF. Have slight
chance PoP for Fri and dry conditions for Sat, but these are
uncertain.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A large area of low pressure to the southeast over the western
Atlantic will remain nearly stationary or drift slowly southeast
through Sunday. At the same time, high pressure will be wedged
in across the Northeast. This will keep the area under a mainly
NE flow and on the western periphery of some rain.

This will be a mainly VFR forecast with a chance of MVFR at the
coastal terminals, especially at KGON. Showers will generally
stay east of the area, but could briefly impact KGON. Plan to
just carry VCSH for KGON through 00Z.

Winds will be NE at 10-15 kt this afternoon with the eastern
terminals, specifically KGON and KISP, gusting to 25-30kt.
Gusts will diminish this evening, but remain occasional at KGON
during the overnight hours. Gusts at KGON and KISP return on
Sunday but will be bit weaker.

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

Can not rule out an occasional gust to 20kt early to mid
afternoon.

Brief MVFR possible overnight.

OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...

Sunday: VFR. NE winds G15-20 kt possible, highest east.

Monday: VFR.

Tuesday and Wednesday: Mainly VFR, with pockets of MVFR
in SHRA. E/NE G15-20kt possible at the coastal terminals.

Thursday: Chance of MVFR in SHRA.

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

&&

.MARINE...
Offshore low pressure continues to bring gusty winds to the eastern
waters and 5+ ft swell to the ocean waters. The low will slowly
drift southeast, with 25 kt gusts likely ending everywhere late this
evening or early tonight (with the exception of the far eastern
ocean zone where 25 kt gusts could linger). However, Small Craft
Advisory conditions will continue on the ocean waters for some time
with 5+ ft seas. Seas peak tonight through Monday at 6 to 8 ft. The
Small Craft Advisory has been extended into Monday, but will likely
need to be extended further over the next several forecast
cycles. An extended period of hazardous ocean seas and rough
conditions at the inlets should remain through at least Wed.
Seas may start to diminish below 5 ft Wed night into Thu, but
could come back up again later on Thursday.

&&

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

Basin avg QPF from Wed into Thu night should range from 3/4 to 1
inch. Only minor nuisance impacts expected at most, mainly on
Thu.

&&

.TIDES/COASTAL FLOODING...
Coastal flooding will continue into Monday, but impacts and
areal coverage will be on the downswing as astronomical tides
continue to lower. The offshore low responsible for the easterly
swell that has helped pile water into the area will slowly work
southeast through early next week. There will be one more cycle
of widespread coastal flooding on Sunday with the potential for
localized moderate, especially for the south shore back bays of
Nassau. The high tide cycles tonight and Sunday night will
feature more localized minor flooding for locations adjacent to
Lower NY Harbor and western LI Sound. However, an advisory is in
effect for late tonight for the south shore back bays of Queens
and Nassau where minor flooding will be a bit more widespread.
The south shore back bays of western LI will likely have issues
through Monday.

As for surge guidance, leaned toward a blend of the TOFs, ETSS
and Steven`s 50th percentile. However, Steven`s guidance has
been overdone in the south shore back bays of LI, likely due to
no wind forcing (E/SE winds). This has been accounted for with
some downward adjustment. This was particularly noticeable over
the eastern bays of LI, where there has been little if any
flooding noted.

The high rip current risk continues through Monday evening due
to a prolonged period of easterly swells.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from noon to 5 PM EDT Sunday for CTZ009-
     010.
NY...Coastal Flood Advisory from noon to 5 PM EDT Sunday for NYZ071-
     073-078-176-177.
     Coastal Flood Advisory from 10 AM to 4 PM EDT Sunday for
     NYZ072-074-075-080-178-179.
     High Risk for Rip Currents through Monday afternoon for NYZ075-080-
     081-178-179.
     Coastal Flood Advisory from 10 PM this evening to 2 AM EDT
     Sunday for NYZ178-179.
NJ...Coastal Flood Advisory from 10 AM to 4 PM EDT Sunday for
     NJZ006-106-108.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ332.
     Small Craft Advisory until 6 PM EDT this evening for ANZ340.
     Small Craft Advisory until 6 PM EDT Monday for ANZ350-353-355.

&&

$$

SYNOPSIS...BG/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...BG
AVIATION...DW
MARINE...BG/JT
HYDROLOGY...BG/JT
TIDES/COASTAL FLOODING...DW