547
FXUS61 KOKX 181006
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
606 AM EDT Sat May 18 2024

.SYNOPSIS...
A weakening upper level trough will approach from the west today
and move across the area tonight, otherwise surface high pressure
will remain in control through the middle of next week. A cold
front approaches late in the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Subtle adjustments made with this update, mainly to push back
low chances of showers today.

High pressure will continue to ridge south across New England
and into the forecast area. However, a weakening upper level
shortwave trough will approach from the west today and move
across the area tonight. At the same time, a large area of low
pressure over the western Atlantic will continue to send Atlantic
moisture into the area. Together, plan on lots of clouds, a
light NE-E flow, and a low chance of showers. Patchy light
rain/drizzle is also possibility across eastern LI and SE CT.

Highs are forecast to range from the lower 60s across far
eastern LI and SE CT, to around 70 from NYC and points north and
west. This is generally a few degrees below normal. However,
with the cloud cover, expect lows tonight in the 50s, slightly
above normal. Temperature guidance is generally in good
agreement with a slight upward trend.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
Surface high pressure along the new England coast remains in
control during this time. Patchy light rain/drizzle may linger
in the morning for far eastern areas, otherwise expect gradual
improvement with decreasing clouds from west to east in the
afternoon. This could be short-lived though for eastern LI and
SE CT, where low clouds may linger or redevelop during the
nighttime hours. Any clouds work east on Monday along with the
surface ridge axis. Aloft, a high amplitude ridge builds over
top of the area.

Temperatures will be on the uptick Sunday into Monday due to a
lot more sun. Sunday will be a touch warmer than Saturday, but
jumping to 75 to 80 north and west of NYC on Monday, with much
of the coast getting to around 70.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
*Key Points*

*Above normal temperatures through midweek.

*A cold front approaches late in the week, bringing the next
 chance of showers and thunderstorms.

Upper ridging noses into the region from the southern US early to
mid week, becoming suppressed late in the week in response to a
developing closed upper low drifting east across the northern
plains/Great Lakes. Quite a bit of model spread on the evolution of
this low, which manifests in timing and progressiveness differences
in the resultant cold front pushing towards and into the region late
in the week.

Before then, good agreement in high pressure over the region this
weekend, slowly sinking se of the region and developing a return
deep SW flow into the region by midweek. The result will likely be
dry conditions with temps moderating to 10 to 15 degrees above
normal away from the coast Tue thru Thu. Based on setup, and 850mb
temps in the mid teens, have leaned away from cooler deterministic
NBM and towards the higher NBM 50th percentile (high in the mid 80s)
for NE NJ and areas to the NW. NBM 75th percentile has temps
approaching 90 in this area, which is plausible with deep mixing and
SW flow. Meanwhile, SW flow off mid 50 degree waters will likely
keep temps in 70s along the coast, but still seasonable.

Shower/tstm potential exists ahead/along pre-frontal trough and cold
front, but with aforementioned upper low and frontal timing
differences, have capped potential at low chance, possibly as early
as Wed eve, with better chance Thu aft/eve. CSU MLP marginal severe
storm threat for areas west of the Hudson River Wed eve, and the
entire area Thu aft/eve looks reasonable based on synoptic and
thermodynamic setup.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
Weak high pressure will be in place today through Sunday, with
a weak warm front dissipating as it moves in from the west tonight.

MVFR cigs developing for KGON early this AM, and will likely develop
across KISP and KBDR by mid morning. MVFR cigs will likely be
stubborn for the eastern terminals through the day. Meanwhile NYC/NJ
terminals will likely remain VFR this AM, with patchy MVFR cigs
possible in the aft. Increasing likelihood for MVFR cigs spreading
west into NYC/NJ terminals tonight.

Isolated shower threat for eastern terminals this AM, then for all
terminals in the aft/eve.

NE/E winds 10 kt or less today into tonight.

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

Slight prob for MVFR cigs during AM push, and low prob for PM
push. MVFR conds likely for Sun AM push. Isolated shra possible
for eve push.

NE winds of 7 to 10 kt, likely becoming E/SE in the afternoon with
hybrid sea breeze development, except KLGA.

OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...

Late Tonight: MVFR. NE/E winds less than 10 kt.

Sunday...MVFR or lower in the AM, gradually improving to VFR.
Light E/NE winds.

Monday...MVFR AM, then VFR.

Tuesday-Wednesday...VFR.

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

&&

.MARINE...
SCA has been expand to include the ocean zones from Fire Island
Inlet to Montauk Point. An easterly swell due to a large area
of low pressure over the western Atlantic looks to keep seas
around 5 ft through much of the day. Otherwise, a weak pressure
gradient over the waters will likely lead to sub SCA levels
through the middle of next week. The exception will be the
potential for marginal southerly SCA gusts in and around the
entrance to NY Harbor with coastal jet formation Wed aft/eve.

&&

.HYDROLOGY...
There are no hydrologic issues through the middle of next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for ANZ350-
     353.

&&

$$

SYNOPSIS...NV/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...NV
AVIATION...NV
MARINE...NV/DW
HYDROLOGY...NV/DW