000
FXUS61 KOKX 202346
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
746 PM EDT Fri Oct 20 2023
.SYNOPSIS...
A broad area of low pressure will approach from the west
tonight. This system will spawn a rapidly deepening low near the
area Saturday. The low departs to the northeast Sunday as high
pressure starts to builds in. The high will be centered over the
area early Tuesday and remain in control through at least
midweek. A weak cold front may move through the area sometimes
at the end of the week, with high pressure returning thereafter.
&&
.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --
Forecast on track with only minor adjustments to reflect the
most recent observations.
Periods of rain can be expected tngt as the upr trof to the west
continues to approach and works on the subtropical moisture feed
over the Atlantic. A weak low analyzed east of Hatteras will
race newd tngt approaching the Maritimes by 12Z Sat. No wind
impact with this and the rain shield associated with the low
will remain well east of the cwa.
Some locally heavy stripes of rain possible tngt with pwats
around an inch, but with another low beginning to spin up south
of the region after midnight, this could temporarily cut off the
moisture feed into Sat mrng, reducing the excessive rain threat.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY NIGHT/...
Deep low pres is looking increasingly likely for Sat, with the
models coming into agreement with the 12Z cycle.
The 12Z NAM has a 981 low over Cape Cod at 21Z Sat, the GFS a
980 low over Montauk at 18Z, and the ECMWF a 983 low near
Nantucket at 18Z.
These solns indicate rapid deepening invof the cwa on Sat, with
locally hvy rainfall thru at least the mrng, and increasing
winds thru the day. Although the exact track and intensity is
uncertain based on the model spread, peak wind gusts around 40
mph seem likely, particularly LI, and 1-2 inches of rain where
the main band sets up nw of the low.
The possibility exists for stronger winds gusting in excess of
50 mph if the model trends hold. Winds were increased above
model guidance in the grids. Peak winds over land may be
limited in the eve, especially inland, by the cooling bl. LI
should remain gusty due to the warm waters.
The rain tapers off from west to east late in the day into the
eve, with most of Sat ngt dry.
The NBM with local adjustments was used for temps.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
By Sunday morning, the strong surface low will be centered well to
our northeast and will continue to depart the area as high pressure
starts to build in from the west. Aloft, a couple more shortwaves
swing through the upper level trough through Sunday. This will
result in mostly cloudy skies sticking around through Sunday and
even a slight chance of some additional light showers for the
northern half of the area. Given the strong low and resulting tight
pressure gradient, forecast soundings support good mixing in a
northwest flow. Expect wind gusts up to 30-35 mph.
The pressure gradient starts to relax as high pressure builds in.
The high will remain in control through at least midweek. Several
dry days with sun can be expected. There also looks to be a couple
of days with decent radiational cooling conditions. Have blended in
the CONSMOS and MEX guidance Monday night and Tuesday night to
capture this.
Global guidance is not in as good agreement for the end of next
week. Right now it looks like there is potential for a weak cold
front to pass through and bring some light showers. Given the
uncertainty, just stuck with NBM for PoPs which was mostly dry.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
An area of low pressure rapidly deepens just east of the area
into Saturday.
Mainly MVFR to IFR conditions with occasional showers expected
through Saturday morning. Showers will become more numerous
late tonight into Saturday morning. An isolated thunderstorm is
not entirely out of question, though confidence and coverage
remains too low to include in TAFs. Brief improvement to VFR is
possible this evening. Showers come to an end from west to east
into early Saturday afternoon with gradual improvement to MVFR
and VFR.
S or SE flow this evening with speeds around 10kt. Winds
decrease and eventually become variable tonight, veering NW by
Saturday morning. Speeds substantially increase late morning,
20 to 25 kt with gusts 30 to 35 kt through Saturday evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of category changes and wind shift could be off by a few
hours.
Isolated thunderstorm possible at terminals through Saturday
morning.
Isolated gusts up to 40 kt possible Saturday afternoon.
OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday Night: Mainly VFR. MVFR possible, especially early.
Gusty NW wind 20-25G30-35kt.
Sunday: MVFR cigs possible, especially in the morning. W to NW wind
gusts around 25-30 kt.
Monday: VFR. Gusty NW flow 15-20 kt in the morning.
Tuesday: VFR.
Wednesday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Low pres will deepen near the waters late tngt and Sat. Winds
blw sca lvls tngt, but seas around 4 ft on the ocean. Winds and
seas pick up on Sat, and a gale warning has been issued for all
waters. Peak winds Sat aftn and eve.
Winds will remain elevated Sunday through early Monday. As of right
now the winds look like they max out on Sunday just below Gale
criteria on the ocean waters. Wind gusts are expected to be between
30 and 33 kt with occasional gusts up to 35 kt. On all other waters,
winds will gust up to 30 kt. 25 kt gusts may linger on all waters
into early Monday morning. Waves will also remain elevated on
Sunday. On the ocean waters expect 7-9 ft waves to lower to 4-5 ft
Sunday night and then fall below 5 ft on Monday morning. Waves on
the Long Island Sound will likely remain 5-6 ft through early Sunday
night as well. Thereafter, with high pressure in control, conditions
will be below Small Craft Advisory criteria.
&&
.HYDROLOGY...
About 1-2 inches of rain, with some locally higher amounts, are
expected thru Sat. Some minor urban and poor drainage flooding
are the most likely impacts attm, although some fast responding
streams could flood within the axis of the heaviest rain.
There are no hydrologic concerns Sunday through next week.
&&
.TIDES/COASTAL FLOODING...
From the prolonged onshore fetch and piling of water, a few
sites in and around the South Shore Bays and possibly the lower
NY Harbor could reach minor coastal flood benchmarks for the
aftn high tide cycle on Saturday. One mitigating factor
Saturday will be the NW offshore flow developing and increasing
during the day.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Gale Warning from noon Saturday to 6 AM EDT Sunday for ANZ331-
332-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...JMC/JT
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JT
AVIATION...MW
MARINE...JMC/JT
HYDROLOGY...JMC/JT
TIDES/COASTAL FLOODING...