discussion on 2023-08-31

000
FXUS61 KOKX 311135
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
735 AM EDT Thu Aug 31 2023

.SYNOPSIS...
High pressure builds in through tonight, then remains in control
through the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Forecast on track early this morning.

An upper trough will move off the New England coast today with
heights rising through tonight as ridging starts to move towards
the area. Sprawling high pressure at the surface across the
Great Lakes region will build towards the northeast and settle
overhead tonight.

An 120-130 kt 250 mb jet streak near the New England coast up
into the Maritimes will help lift high cirrus clouds from
Tropical Cyclone Idalia. These clouds look to be thickest
closest to the coast this morning and early afternoon. The jet
pushes further east through the day which should help push the
cirrus clouds south and east. Increasing subsidence and building
heights aloft will also aid in diminishing the clouds this
afternoon. By evening, the expectation is that all areas will
be mostly clear.

High temperatures today will be several degrees below normal
for the end of August, generally the middle 70s. Dew points
should fall into the middle to upper 40s most spots, making it
feel comfortable. It will also be breezy with northerly winds
10-15 mph and a few gusts up to 20 mph.

A cool night is in store with temperatures falling into the
upper 40s and low 50s inland and lower to middle 50s most
elsewhere. The NYC metro will likely fall into the lower 60s.

Tropical Cyclone Idalia is forecast to pass well to our
south, and Tropical Cyclone Franklin will continue to bring
indirect impacts to the coast. See the Tides/Coastal Flooding
section below. Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on this,
and other, tropical systems.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
High pressure over the northeast will remain in control into
the upcoming weekend. Upper ridging continues to build towards
the area, but the core should remain across the central states.
The atmospheric column will be dry on Friday with skies likely
clear through the day. Highs will continue below normal in the
middle to upper 70s. Cool conditions remain for Friday night
with lows in the 50s to around 60 degrees.

The air mass moderates on Saturday as the center of the surface
high shifts offshore. The return flow around the high will bump
dew points up a bit into the middle and upper 50s in the
afternoon and evening. A few high clouds may also spill around
the periphery of the upper ridge as a shortwave begins to move
towards Southeast Canada and Northern New England. Highs will be
in the upper 70s to around 80 degrees.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The long term is largely dominated by a large high pressure
system that traverses the area through the middle of next week.

A weakness in the high pressure system on Sunday may give way
to a very weak cold front that likely pushes through without
any precipitation. High pressure then builds back into the area
from the southwest as an upper level ridge moves back into the
area by the middle of the week. This is associated with a
warming trend through the period. Highs on Sunday will be in the
middle to upper 80s with temperatures increasing Monday and
Tuesday with highs in the upper 80s to middle 90s. The heat then
is expected to remain fairly persistent through the end of next
week with highs Wednesday and Thursday still above average in
the middle 80s to low 90s.

The one questionable thing in the forecast is what happens to the
remnant of Tropical Cyclone Idalia. Some global models have the
remnants of, or a reinvigorated, Idalia retrograding closer to the
Canadian Maritimes as an upper level ridge encompasses the low.
There is still significant uncertainty in the its eventual placement
and strength but models have been consistent enough with this
potential solution to be worth mentioning.

For the latest official forecast information on Tropical
Cyclone Idalia, please monitor the National Hurricane Center at
https:/www.nhc.noaa.gov

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --A large area of high pressure centered over the Great Lakes
will build east and into the area through the end of the week.

VFR. N winds 10 to 15 kt. Gusts up to 20-25kt expected this
morning, diminishing in the afternoon. N wind around 10 kt
continues overnight and into Friday morning.


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

Gusts may be more occasional than frequent.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...

Friday-Monday: VFR.

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

&&

.MARINE...
N wind gusts on the ocean may approach 20-25 kt this morning. A
continued SE swell from distant Tropical Cyclone Franklin will also
keep seas elevated around 5-7 ft today. The swells begin to slowly
subside, allowing seas to begin to subside tonight. However, some 5
ft seas may linger early Friday morning. The SE swells will also
bring elevated seas east of the Mouth of the Connecticut River. No
changes were made to the ongoing SCA here and on the ocean. Seas
subside further on Friday. Sub-SCA conditions are expected
Saturday through Tuesday as high pressure builds in and then
slides offshore.

&&

.HYDROLOGY...
No hydrologic impacts are expected through the middle of next
week.

&&

.TIDES/COASTAL FLOODING...
Long period SE swells emanating from distant TC Franklin in
the Western Atlantic will continue to produce high surf,
dangerous rip currents, and scattered beach/dune erosion into
this evening.

A high risk of rip currents remains at all ocean beaches
through this evening. SE swells begin to subside on Friday, but
about a 10 second period may persist which could lead to
another high risk of rip currents. Have held off on extending
the rip current statement through Friday for now to allow the
next shift to reassess the latest data.

A High Surf Advisory remains in effect through 6 pm.

In addition, the combination of the long period swells and
the recent full moon (high astro tides) will lead to minor
flood benchmarks being exceeded for the south shore back bays of
western LI with tonight`s high tide. Water levels will likely
just touch minor benchmarks across the lower NY Harbor and
coastal Fairfield County CT coast. Have issued another coastal
flood statement. The latest guidance indicates that isolated
minor flooding is possible with Friday mornings high tide cycle
across the south shore back bays and possibly coastal Fairfield.
More widespread minor coastal flooding is anticipated across
the south shore back bays during Friday nights high tide. Any
coastal flooding across the Lower NY Harbor and coastal
Fairfield appears more localized Friday night. The threat for
coastal flooding diminishes on Saturday, but could still be
localized for the south shore back bays.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents through this evening for NYZ075-080-081-
     178-179.
     High Surf Advisory until 6 PM EDT this evening for NYZ080-081-
     179.
     Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for
     NYZ178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ332.
     Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.

&&

$$

SYNOPSIS...DS/MW
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...MW
AVIATION...MW
MARINE...DS/MW
HYDROLOGY...DS/MW
TIDES/COASTAL FLOODING...