553
FXUS61 KOKX 111617
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1217 PM EDT Sat May 11 2024
.SYNOPSIS...
-- Changed Discussion --
High pressure builds in from New England this afternoon, 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.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Forecast on track this afternoon. A weak high ridges down from
New England this afternoon with a mid level ridge overhead.
These features are all within a larger mean upper level trough
over eastern North America. Clouds will vary in coverage to this
afternoon with at least partly sunny skies for most areas.
Middle and high clouds should begin to increase late.
Highs will be in the upper 50s to lower 60s, warmest away from
the immediate coast, 5-10 degrees below average for this time of
year. ESE flow is already developing which will likely cap off
any temperature rise near the coast for the remainder of the
afternoon.-- End Changed Discussion --
&&
.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 SATURDAY/...
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
mid levels, 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 /16Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Weak high pressure initially will give way to an approaching weak
frontal system tonight into early Sunday.
Mainly VFR conditions are expected through the TAF period.
Winds shift to the E and SE this afternoon into tonight. Wind
speeds will be generally near 5-10 kts. NYC terminals a few kts
higher with max wind speeds closer to 12-13 kt at times this
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shift to the SE this afternoon may be off by a
few hours.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
Sunday: Chance of MVFR or lower in showers.
Monday: Mainly VFR. Isolated showers possible mainly north of
NYC terminals.
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-- End Changed Discussion --
&&
.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 minor coastal flood benchmarks.
A coastal flood statement has been issued for Southern Nassau
County between 9PM EDT this evening and 1AM Sunday EDT overnight.
No additional coastal flooding is anticipated Sunday into next
week as astronomical tide levels continue to subside.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JM/BR
NEAR TERM...BR/DS
SHORT TERM...BR
LONG TERM...JM
AVIATION...JM
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...