843
FXUS61 KOKX 120557
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
157 AM EDT Sun May 12 2024

.SYNOPSIS...
A frontal system approaches from the west tonight and then
passes south and east of the area on Sunday. High pressure
returns Sunday night. A warm front passes north of the area
Monday into Tuesday. Low pressure may impact the area for the
middle of the week, with another frontal system possible by next
weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Have adjusted POPs with this update. Showers have
underperformed this morning, so cut back precipitation to far
western areas. It looks like the latest CAMs are trying to
develop persistent showers for the NYC metro and areas south and
west of the NYC metro later this morning while other areas
remain mostly dry, so have adjusted the forecast accordingly.

A large upper level trough remains over Eastern North America.
Within this trough, a middle level ridge will push east of the
area thsi morning, followed by a shortwave trough. At the
surface, high pressure continues to ridge down from northern New
England. An associated frontal system will slowly approach with
lift increasing west of the NYC metro. Showers will accompany
the increased lift, especially across NE NJ and the Lower Hudson
Valley, slowly making their way towards the NYC metro around
day break. Mainly light showers are expected with a small chance
for a brief occurrence of moderate intensity.

A chilly night is in store despite the increasing cloud cover.
Lows look to fall into the middle and upper 40s for most spots and
around 50 degrees in the NYC metro. These low temperatures range
from 5-10 degrees below normal for this time of year.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
The aforementioned shortwave becomes a broad closed low
overhead early Sunday morning. There will be two separate areas
of middle level energy within the low, one to our northeast and
then another to our south and west. The models are also in good
agreement with the cutoff low quickly shifting to our east
around midday. The remaining energy to our south and west will
shift to a less favorable position for supporting the shower
activity. The upper trough and cutoff low will then slowly shift
to a position near or just off the New England coast Sunday
evening.

Showers, mainly on the light side, will continue from around
the NYC metro/Hudson River corridor in the morning. The showers
will try to shift eastward in the morning, but will likely
encounter subsidence behind the lead energy and slowly dissipate
as they move over southern CT and western/central Long Island.
The showers will continue to dissipate early in the afternoon
with dry conditions likely returning around 19z. Total rainfall
amounts range from one to two tenths west of the NYC metro, a
few hundredths to a tenth in the NYC metro, and possibly a trace
to see a few hundredths east of the Hudson and NYC metro.
Locations on the east end and southeast CT may remain completely
dry. Lingering middle level moisture likely leads to mostly
cloudy skies for the remainder of the daytime hours.

The other story for Sunday will be unseasonably cool
temperatures with highs only reaching the middle and upper 50s.
These highs are 10-15 degrees below normal for this time of
year.

Heights will rise Sunday night as the upper trough continues
departing to the east. Surface high pressure will be in place
leading to dry conditions. Clouds should slowly diminish
through the night with mostly clear to partly cloudy skies by
early Monday morning. Another chilly night is expected with lows
in the 40s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Dry wx is expected on Mon with high pres along the coast. Sly
flow develops during the day with a warm front to the N and sea
breeze impacts. This will modify temps for most of the area E
of the Hudson River. With the boundary to the N and some energy
embedded in the flow aloft, a few shwrs are possible Mon ngt and
Tue. Greater instability could yield some tstms N and W of NYC
Tue aftn and eve, then low pres approaches from the SW and rain,
with a few embedded tstms, overspreads the area Tue ngt into
Wed. Despite the cool ocean, the warm airmass yields highs in
the 60s and 70s on Tue per the NBM. Mixing down the GFS from h85
would produce mid 70s without adding in the seasonal solar
adjustment which would bring the numbers to around 80. Stuck
with the NBM for now, but some higher readings possible in NJ
and up the wrn portion of the Hudson Valley. Clouds and residual
rain keep temps lower on Wed, then pcpn chances subside Wed ngt
into Thu. Temps rebound on Thu with more sunshine despite nely
flow. Another frontal sys is possible late Fri into Sat. The
timing and track are a little uncertain, with the ECMWF slower
than the GFS. As a result, the blended approach using the NBM
was used.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A weakening frontal system moves in going into today. Weak high
pressure return later today and tonight.

Some light rain showers are expected with this frontal system
with higher chances for NYC terminals, KHPN and KSWF and lesser
chances for KISP and KBDR. KGON may not receive any rainfall.
Chances are too low for rain for KGON to include in their TAF.

VFR is expected to transition to MVFR going into this morning.
Some MVFR may last into this afternoon, but otherwise mainly VFR
conditions are expected this afternoon into tonight.

Wind speeds less than 10 kt expected during the TAF period. Wind
direction overall southerly on average becoming more SW late in
the TAF period.

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

MVFR timing could vary from TAF by a few hours. Some fluctuation
between VFR and MVFR possible going into this morning.

OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...

Late Sunday night through Monday: VFR.

Tuesday: MVFR or lower possible in mainly afternoon showers, an
isolated thunderstorm possible inland. S winds 15kt coastal
terminals.

Tuesday night: MVFR likely in showers and possible tstms.
S winds 10-15kt coastal terminals.

Wednesday: MVFR or lower still likely in showers and t-storms.
SE winds 10-15G20kt, becoming NE late day and at night.

Wednesday night: VFR. N winds 10-15G20kt.

Thursday: VFR.

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

&&

.MARINE...
No changes to the winds and seas at this time.

Seas east of Moriches Inlet are likely to end up around 4 ft
this evening and may occasionally reach 5 ft. Not anticipating
the need for an SCA. Conditions will remain below SCA levels
through Tuesday night with a weak pressure gradient over the
waters. There could be period of marginal 5 ft seas on the ocean
Mon and Tue. A SCA will be needed on the ocean Wed with low
pressure, and possible elsewhere. SCA cond may linger through
Thu, subsiding by Fri.

&&

.HYDROLOGY...
No hydrologic impacts expected through next week.

&&

.TIDES/COASTAL FLOODING...
Only localized minor coastal flooding is expected for the
most vulnerable locations along the south shore back bays of
Nassau County with high tide tonight. A coastal flood statement
remains in effect. Otherwise, no additional coastal flooding is
anticipated as astronomical tide levels continue subsiding into
early next week.

&&

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

&&

$$

SYNOPSIS...JMC/DS
NEAR TERM...BR/DS/MET
SHORT TERM...DS
LONG TERM...JMC
AVIATION...MET/JM
MARINE...JMC/DS/MET
HYDROLOGY...JMC/DS
TIDES/COASTAL FLOODING...