000
FXUS61 KOKX 200943
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
543 AM EDT Wed Sep 20 2023
.SYNOPSIS...
High pressure remains over the region through Thursday night
then slides northeast of the area late Friday into Saturday. A
developing low pressure system then moves northeast into the
region from Saturday into early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast on track with just some minor adjustments to reflect
current observations. Otherwise, high pressure remains over the
region today with pleasant conditions. Sunny skies with
temperatures in the low to mid 70s can be expected.
Tonight, light winds and clear skies will result in good radiational
cooling. Lows will fall into the 40s and 50s.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The tranquil and pleasant conditions continue through the short term
period with high pressure remaining over the region through Thursday
night. The high will slide offshore on Friday, giving way to clouds
during the second half of the day as clouds from the south start to
filter into the region.
High temperatures on Thursday will be in the lower and middle 70s.
As the high shifts to the east, winds on Friday become more
easterly, and increasing high clouds for the second half of the day
should keep temperatures a few degrees cooler. Expect highs on
Friday to be in the upper 60s and lower 70s. Good radiational
cooling Thursday night will once again allow temperatures to fall
into the 40s and 50s, however a few locations right around the NYC
metro area could stay right around 60 degrees.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Confidence is increasing that a coastal low pressure system with a
southeast US origin will impact the area this upcoming weekend.
Global models and their respective ensemble systems have come into
better agreement on the synoptic pattern, though some differences do
exist in the handling of this system with respect to track and
timing. The ridging in that was in place over the northeast during
the week pushes further offshore by Friday evening. At the same
time, a slow moving upper/mid level low originating over the
Carolinas pushes slowly north and is somewhat impeded by the ridging
in place over the northeast. This upper low remains across the
northeast for much of the weekend before getting absorbed by another
mid/upper level trough dropping through the northeast into early
next week.
A surface low begins to take shape off the Carolina coast and
deepens somewhat as it heads northeast into the weekend. While there
remains some differences in the strength, track, and timing of this
feature in the guidance, a more general consensus that the surface
low will track near, or just east of the local area seems more
apparent with the latest runs. Thus, it appears more likely that a
wet, windy weekend is in store across the Tri State.
Increased easterly flow and precipitation onset looks to begin by
early to mid morning on Saturday, with most guidance indicating an
inverted trough feature associated with the main sfc low approaching
by this time. Global ensemble (GEFS, CMCE, ECE) means for precip
have increased since yesterday with better overall agreement, and
thus the NBM all paint a widespread 1.5-2.5" Saturday into early
Monday for the area, but the spread in individual ensemble members
continues to be quite large. The highest amounts look to be over
Long Island and southern CT, but will depend on the eventual track
of the system.
NBM v4.1 probabilities of >2" over the 24 hours ending 12Z Sunday
show a widespread 20-30% across Long Island and CT, up from about 10-
15% this time yesterday. However, the NBM v4.1 probabilities of >1"
in any 6 hours still remains low as a signal for periods of heavier
rainfall. Details should come into better view over the next few
days with additional high resolution/convective allowing guidance
sources available for that time horizon which will help better
diagnose the potential for locally heavy rainfall on Saturday into
Sunday.
By Monday, the surface low heads north of the area, as the upper low
is absorbed by a larger system to the northeast. Some gradual
clearing/drying out is then likely Monday into Tuesday. Seasonable
temperatures are forecast for the period, though clouds and rain
over the weekend may allow for slightly cooler conditions.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
VFR.
High pressure continues to build west of the terminals through the
TAF period.
NW winds 5-10kt, with outlying terminals under 5 kt. The winds then
back slightly to the WNW Wednesday and mainly settle in at 7-10kt.
Coastal terminals may back a bit more to the WSW Wed afternoon
before veering back to WNW by 00Z.
....NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No amendments expected.
OUTLOOK FOR 6Z THURSDAY THROUGH SUNDAY...
Wednesday Night - Friday: VFR.
Saturday and Sunday: MVFR or lower likely in rain. E gusts 15-25 kt,
possibly higher at the coastal terminals. Strongest winds at this
time look to be on Saturday.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n900
&&
.MARINE...
Generally looking at sub-SCA conditions through Friday on all the
waters, however seas on the ocean waters will gradually increase on
Thursday and remain around 4 ft through Friday as low pressure
develops well south of the region and some swells move into the
area. There is a low end chance that some seas could reach 5 ft on
Friday.
SCA conditions appear likely for most, if not all, of the
waters on Sat. There is a chance for gales, particularly on the
eastern waters and the ocean. An SCA is possible again on Sun,
then gradual improvement on Mon.
&&
.HYDROLOGY...
No hydrologic impacts are anticipated through Friday.
Confidence is increasing for a widespread precipitation event this
upcoming weekend. WPC has placed the entire CWA in a marginal risk
of excessive rainfall on Saturday. Hydrologic impacts will be
possible if locally heavier rainfall occurs, though confidence in
this scenario low at this time.
&&
.TIDES/COASTAL FLOODING...
There is a moderate rip current risk on Wednesday for all the area
atlantic facing beaches. There is a high rip current risk for the
Suffolk County atlantic facing beaches on Thursday, with Nassau and
NYC remaining moderate.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BC/DBR
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...DBR
AVIATION...DBR
MARINE...BC/DBR
HYDROLOGY...BC/DBR
TIDES/COASTAL FLOODING...