-- Discussion containing changed information from previous version are highlighted. --
727
FXUS61 KOKX 052130
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
530 PM EDT Sun May 5 2024

.SYNOPSIS...
High pressure centered near Nova Scotia and extending along the
New England coast continues to weakens and slowly shift to the
east through tonight ahead of an approaching cold front from the
west. The front eventually tracks through the region late
Monday into Monday night before stalling to our south. High
pressure then briefly returns before the stalled boundary lifts
back north as a warm front Tuesday night. A series of low
pressure centers then impact the weather from Wednesday through
Saturday.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --
No changes were made in this update. The forecast remains on
track.

An upper level ridge offshore continues to move into the Western
Atlantic tonight as a shortwave tracks through the northeast,
with the flow becoming more zonal across the region. Light rain
showers will accompany the shortwave. At the low levels weak
warm advection will be setting up late tonight. And while
temperature may fall a couple of degrees into tonight,
temperatures will be mainly steady with the cloud cover and
precipitation. And then as the warm advection begins
temperatures will hold nearly steady or rise a degree or two
toward Monday morning. The CAMs handle the areal extent and
timing of the precipitation and leaned toward those
probabilities. And with the shortwave moving east precipitation
will be tapering off and ending across much of the areas by
Monday morning. While some fog is possible tonight with
saturated low levels, and onshore flow, do not think that
visibilities will lower much below 3 miles to include in the
forecast at this time.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
A closed upper low will track through eastern Canada Monday into
Monday night, and with the flow more zonal a weak cold front
will be approaching during the day. While the flow is more
progressive the latest trends have been to move the front
through a little slower than previous forecasts. Continuing warm
advection ahead of the cold front, and possibly some breaks in
the cloud cover will allow for temperatures to rise into the
lower 70s across much of the region with coastal areas remaining
in the mid to upper 60s. While the NBM temperatures were
several degrees higher than the MOS guidance, with the cloud
cover have used a blend of the NBM with the MOS to have
temperatures several degrees cooler. However, if there are more
breaks in the cloud cover than temperatures inland may rise
into the mid and upper 70s. Have also included the chance of
isolated thunderstorms as surface based CAPE increases to few
hundred J/kg and instability also increases. In addition the
CAMs are showing a developing line of convection ahead of the
cold front during the later half of the afternoon and into the
early evening. The front does move through the region Monday
night, and with the zonal flow stall south of the region.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
High pressure briefly noses in on Tuesday with a weakening ridge
aloft before a stalled front to our south slowly lifts north as a
warm front Tuesday night. Weak low pressure from the Great Lakes
moves into the northeast on Wednesday in tandem with a mid-level
shortwave helping the warm front advance through the area. This will
also advect in more moisture with models indicating 1.25-1.45"
PWATs. 850mb warm air advection will help increase instability and
drive better development of showers and thunderstorms. Temperatures
on this day will be quite warm into the low-80s for NE NJ, and parts
of the Lower Hudson Valley and the NYC metro and in the low-70s for
eastern areas. Model sounding show decent shear, increasing CAPE
aloft with many areas 1000 J/kg or greater, decent speed shear and
increasing midlevel lapse rates. Gusty winds and small hail,
therefore, may be possible with some thunderstorms. When this
timeframe falls within the CAMs, we`ll have a better idea of how
great and exactly where in the CWA this risk will be.

A cold front will then pass through Wednesday night as the low exits
to our east. High pressure will settle in again, briefly, with more
of a zonal pattern aloft.

Another low pressure system approaches from the Ohio River Valley on
Thursday, passing through on Friday as the upper-level trough starts
to deepen over the region. Increased mid-level energy will arrive
ahead of the low early Thursday. PWATs again increase ahead of the
low around 1.3-1.5" based on the latest 12Z model guidance. Showers
and thunderstorms will be likely for this. They are less likely to
be as intense due to cooler air in the region.

A new low pressure system will develop to our south and east
Saturday into Sunday as a larger troughing pattern aloft takes
shape, leading to cooler temperatures settling in.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
A frontal system slowly approaches from the west.

IFR cigs remaining through Monday morning then slowly improving to
MVFR/VFR after mid day on Monday. Showers become more likely this
afternoon/evening, then remaining likely well into tonight, then
tapering off overnight.

ESE-SE winds around 10kt or less through this evening with an
occasional gusts up to 20 kts, shifting more southerly late tonight
and remaining southerly through Monday.

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

Timing of MVFR/VFR conditions Monday might be off by an hour or two.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...

Sunday night: IFR with showers ending.

Monday: IFR to MVFR in the morning, then MVFR, becoming VFR in
the afternoon. A slight chance of showers, an isolated
thunderstorm possible.

Tuesday: VFR, becoming MVFR to IFR late at night.

Wednesday: MVFR or lower with a chance of showers. Thunderstorms
possible mainly in the afternoon.

Thursday through Friday: Mainly MVFR. Showers likely, mainly in
the afternoon.

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

&&

.MARINE...
Winds and seas are expected to remain below SCA conditions
through Thursday, but ocean seas may rise to 5 ft Thursday
night.

&&

.HYDROLOGY...
There are currently no hydrologic concerns through this week.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides are running high with the approach of a new
moon Tuesday. Tide levels fell short of Stevens Institute
NYHOPS guidance with the Saturday night high tide cycle, and
most locations fall short of the minor flooding thresholds for
the high tide cycle tonight. At most isolated spots over
Southern Fairfield County may touch minor flooding thresholds.

Statements will be possible for Monday night`s cycle for
Southern Fairfield county, as well as for the south shore back
bays of Nassau County.

The potential of a more widespread minor flooding event that
would necessitate advisories will probably hold off until
Tuesday and Wednesday nights` cycles for these same areas as
well as southern Queens. Statements for these 2 high tide cycles
may be needed for other parts along western LI Sound as well as
lower NY Harbor and Brooklyn.

&&

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

&&

$$

SYNOPSIS...BR/MET
NEAR TERM...BR/MET
SHORT TERM...MET
LONG TERM...BR
AVIATION...20
MARINE...BR/MET
HYDROLOGY...BR/MET
TIDES/COASTAL FLOODING...