000
FXUS61 KOKX 051826
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
226 PM EDT Thu Oct 5 2023
.SYNOPSIS...
High pressure remains in place to our north and east through the
day, before departing farther east tonight into Friday. The high
will give way to an approaching frontal system that will drag a cold
front through the area Saturday into Saturday night. Low pressure
lingers over the Northeast into the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Today will be the last day of above normal temperatures with the
recent warm spell. Highs peaking in the mid to upper 70s away
from south coastal areas.
The aforementioned onshore flow will advect an increasingly
humid airmass and stratus into the area tonight. Some patchy
light rain or drizzle is possible at the very end of the tonight
period.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A digging upper level trough approaches from our west, becoming
negatively tilted before closing off. At the same time, TC Phillipe
approaches from the south and east. Phillipe will stay well to our
east, but aid in increasing the moisture over our area before
getting pulled back west into northern New England. A surface low
associated with the approaching upper level trough will pass well to
our north, but drag a cold front through our area Saturday into
Saturday night.
After a dry week, this set up will allow rain chances to increase
through the day on Friday, and become likely Friday night through
Saturday. Expecting the showers ahead of the cold front Friday
through Friday night to be mostly light. The ECMWF is currently an
outlier showing a higher band of QPF during this time frame and does
not seem to be supported given the expected moisture and
instability. Will have to continue to monitor this trend especially
as the CAMs start to come into play. For now, the WPC as outlined
the area in a marginal risk for Day 2. There is potential for
this to be upgraded to a slight risk as WPC mentions in their
Day 2 ERO based on today`s 12z CAM guidance. Moderate to heavy
showers are then expected with the passage of a cold front
Saturday into Saturday night. Have removed thunder given the
forecast soundings showing very little CAPE through the profile.
Thunder can not be completely ruled out but thinking it will be
extremely isolated. NBM probabilities for 1 inch of rain over
any 6 hour period have actually lowered to less than 10%.
However, probabilities for 1 inch of rain over the 24 hr period
ending 00z Sunday have increased significantly to 65-85% for
most.
Rain tapers off late Saturday night into Sunday morning. Cool
air filters in behind the cold front, with lows Sunday morning
in the 40s.
Refer to the National Hurricane Center, https:/www.nhc.noaa.gov for
official forecasts on Philippe.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
For much of the long term, the area is positioned at the base of a
large trough and associated cut off low pressure system positioned
well to the north centered over Southern Canada. Behind the cold
frontal passage and through much of the week, winds will be
generally out of W/SW. Wind speeds will be a bit breezy Sunday and
into early Monday as the pressure gradient remains fairly tight over
the area as the low pressure initially occludes closer to the area.
Wind speeds lower into Tuesday as the center of the low moves
northward.
Lower heights and a cooler airmass will be advected into the area
allowing temperatures each day in the extended period to be
generally 5 to 10 degrees below average. Highs through the beginning
of the week will only be in the low 60s, eventually rising into the
middle 60s by midweek.
In terms of sensible weather, conditions seems to be generally dry,
though pieces of energy rounding the base of the trough and the cut
off low may result in some showers at times through the week, though
confidence in the timing and placement of any more organized showers
remains low at this time.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
High pressure centered well east of New England coast will
gradually retreat farther offshore through Friday, while a
frontal system approaches from the west.
VFR through early this evening, then widespread IFR/LIFR
conditions overspread the area, mainly after 00Z. Occasional
VLIFR with vsbys 1/4 mile or less. A few showers and/or
areas of drizzle remain possible late tonight into Friday.
S-SE 5-10kt this afternoon will become E-SE this evening at 5
kt or less.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of lowering cigs/vsbys this evening could vary by 1-3
hours.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday: LIFR/IFR to start, improving to MVFR. Chance of VFR for
a period at KEWR/KTEB/KLGA/KSWF. Chance of rain showers and/or
drizzle.
.Friday Night...LIFR/IFR conditions return. Showers becoming
likely, especially across the NYC and Lower Hudson Valley
terminals.
Saturday: MVFR or lower in rain showers. Improving late with
a cold frontal passage and NW winds 10-15kt G20-25kt.
Sunday: VFR. W winds 15-20kt G25-30kt.
Monday: Mainly VFR. Chance of showers late. SW G15-20kt
Tuesday...Manly VFR. Chance of showers. S-SW G15-20kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Some patchy dense fog along the interface of the south shore of
LI and along portions of coastal LI Sound is quickly eroding
early this morning. Otherwise, sub- SCA conditions are expected
through Friday under a weak pressure gradient.
Ocean seas build to 5 ft Friday night as swells increase from TC
Phillipe. By Saturday night, ocean seas are expected to be 9-10 ft.
Winds also increase with and behind a cold frontal passage late
Saturday. SCA criteria gusts are likely on all waters Saturday
night through Sunday night before subsiding.
Ocean seas remain elevated above SCA criteria into early next week
as long period swells from distant Tropical Storm Philippe move into
the waters.
Refer to the National Hurricane Center, https:/www.nhc.noaa.gov for
official forecasts on Philippe.
&&
.HYDROLOGY...
Chances of showers start Friday and become likely Friday night
through Saturday. Periods of moderate to heavy rain are
possible. The WPC has now outlined the western 2/3 of the area
in a marginal risk for Day 2 (Friday) and much of the area in a
marginal risk, with a slight risk for portions of western
Connecticut, for Day 3 (Saturday). Much of the area will likely
see an inch to an inch and a half of rainfall in total. The main
threat is minor nuisance flooding, but there is potential for
isolated flash flooding.
&&
.EQUIPMENT...
Data from the Peconic River at Riverhead NY tidal gauge appears
to have improved. Will monitor the gauge over the next few days
to make sure it is in line with other nearby gauges.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JT/MW
NEAR TERM...NV
SHORT TERM...JT
LONG TERM...MW
AVIATION...DW
MARINE...DW
HYDROLOGY...JT/MW
EQUIPMENT...