951
FXUS61 KOKX 110854
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
454 AM EDT Sat May 11 2024

.SYNOPSIS...
High pressure builds in from New England today, then another frontal
system tracks through Saturday night into Sunday. High pressure
briefly returns Sunday night. High pressure then moves
offshore early next week followed by a low pressure area moving
across midweek. Weak high pressure returns thereafter towards
the end of next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mid-level heights increase today under a weak ridge with anomalously
low heights along with surface high pressure nosing in from New
England. It should allow for more sunshine today, but it will only
be brief before troughing sets back up this evening from the west.

Given the anomalously low heights, cooler air will remain in the
region today with highs only expected to reach low-60s. Some near
the NYC metro may reach the mid-60s while other the immediate coast
of Long Island and Connecticut may only reach the upper-50s. These
temperatures are about 5-10 degrees cooler than average.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
With troughing increasing from the west with an approaching frontal
system in the Great Lakes, cloud cover is expected to increase
Saturday evening into Saturday night. PWATs of 1"+ will also be
advected in from the west with positive vorticity advection and warm
air advection aloft both occurring, aiding in the formation of clouds
and eventual rain.

The trough will guide a weakening frontal system into our area
overnight Saturday with an occluded front. Rainfall will start in
the west overnight and spread eastward toward daybreak and into the
morning. Given the weakening nature of the system, most of the
rainfall will likely occur over far western sections of the area
with much lighter precip expected for the rest of the CWA due to
weaker forcing. Some may only pick up a trace or even remain dry (in
eastern areas), while those in far western sections of our CWA could
see around a quarter inch.

No thunderstorms are expected due to a stable environment.
Temperatures will be cooler on Sunday from the influence of the
trough, cloud cover and rain. Highs are expected to be in the mid-
50s, around 10-15 degrees below seasonal norms.

Expecting slow improvement Sunday afternoon and evening as high
pressure returns once again with weak ridging aloft increasing from
the west. Given the weak high taking over and the weak departing
low, the pressure gradient will be weak, meaning mostly light winds
Sunday night. And with the high pressure clearing clouds, could
expect some weak radiational cooling. Lows are forecast to be in the
mid/upper-40s with the LI Pine Barrens and interior areas in the low-
40s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
In the mid levels, ridging early next week will be followed by a
trough moving in for midweek. Model differences with timing and
evolution of trough with ECMWF showing a cutoff low. ECMWF keeps a
slower movement of the cutoff low while the GFS and Canadian models
depict a faster more progressive trough shifting more east of the
area towards the end of next week.

At the surface, high pressure based in the Atlantic will allow for
more southerly flow to develop early next week. Low level warm air
advection is forecast with a warming trend to daytime temperatures
from Monday to Tuesday. More easterly component of flow develops for
midweek as low pressure approaches from the west. Like the
midlevels, differences become more apparent in model solutions
regarding the speed, location and strength of the low. ECMWF lingers
the low nearby for Thursday and Thursday night while the GFS and
Canadian models show the low moving farther east of the region. Weak
high pressure follows for Thursday into Friday.

Next substantial rain event depicted in the general Tuesday to
Wednesday night timeframe. Tuesday night and Wednesday could present
some embedded thunderstorms, with a slight chance with elevated
instability and colder air aloft moving in.

Temperatures mainly near to above normal during the long term.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Weak high pressure initially will give way to an approaching weak
frontal system tonight into early Sunday.

Outside of some localized IFR to sub-IFR conditions before 12Z
today, mainly VFR conditions are expected through the TAF period.

Winds will be near 5 kts or less into early today with variable
direction for interior locations but more northerly along the
coast. Winds then become more east this morning with more
southeast winds developing this afternoon into tonight. Wind
speeds will be generally near 5-10 kts.

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

IFR to MVFR conditions at KTEB could linger until around 12Z
this morning.

Otherwise, for KEWR, KLGA and KJFK, mainly VFR conditions are
expected during much of TAF period.

OUTLOOK FOR 09Z SUNDAY THROUGH WEDNESDAY...

Late Tonight: Chance MVFR and showers late at night.

Sunday: Chance of MVFR or lower in showers.

Monday: Mainly VFR. Isolated showers possible at KSWF.

Tuesday: MVFR or lower in showers. T-storms possible at night. S-SW
wind gusts 15-20 kt.

Wednesday: MVFR or lower in showers and t-storms. SE to NE wind
gusts 15-20 kt.

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

&&

.MARINE...
Winds and seas should remain below SCA levels this weekend.

Mainly below SCA conditions forecast Monday through Tuesday
with more probable SCA conditions for midweek.

&&

.HYDROLOGY...
No significant hydrologic problems anticipated.

&&

.TIDES/COASTAL FLOODING...
Many locations are expected to fall short of minor coastal flood
benchmarks for high tide cycles tonight. However, the South
Shore Bays of Nassau County NY could have some locations that
touch or slightly exceed their respective minor coastal flood
benchmarks. Winds are expected to transition to more of an
onshore flow later today into tonight. A coastal flood statement
has been issued for Southern Nassau County between 9PM EDT this
evening and 1AM Sunday EDT overnight to address the minor
coastal flooding.

With astronomical tides continuing to lower for the rest of this
weekend and into early next week, no coastal flooding at all is
expected for this timeframe.

&&

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

&&

$$

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