000
FXUS61 KOKX 312020
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
420 PM EDT Tue Oct 31 2023

.SYNOPSIS...
-- Changed Discussion --
A low pressure system develops offshore tonight and passes to the
southeast on Wednesday. High pressure builds into the region
Wednesday night and remains in control through the weekend. A
frontal system may move across the region early next week.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
Weak high pressure situated over New England exits this evening as
a H5 trough swings east toward the region. As it approaches, a
surface frontal wave develops along a boundary draped over the
western Atlantic. This wave passes just south and east of the
region tonight into Wed AM as it tracks off to the northeast.
While the low passes south of the 40/70 benchmark, an inverted
surface trough should help enhance any precipitation on the
western side of the low and produce a chilly light rain for much
of the area, with highest chances along the coast. Fortunately
for those out and about this evening, the rain should largely
hold off until later in the evening, with PoPs gradually
increasing after 00Z. As the low pulls away, temperatures may be
cold enough across portions of the lower Hudson Valley and
interior Connecticut to support some wet snowflakes mixing in
or even changing over, but confidence in a widespread freeze
across Orange Co tonight has lowered with the building cloud
cover and precip from the passing low. Little to no accumulation
is expected in any areas that do see flakes. Otherwise, conditions
could be slow to dry out Wednesday as the trough axis moves
through. Showers may persist into the afternoon hours for
eastern areas of the CWA, though remaining light. Overall QPF
from this event is under half an inch.

Surface high pressure builds into the Tennessee Valley behind
this system, and a cold NW flow will help to limit high
temperatures during the day, likely the coolest since March for
much of the region with the entire region topping out in the
40s.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT/...
-- Changed Discussion --
Cold conditions continue Wed night. Skies clear as the high
builds in and overnight lows range from the upper 20s across
the interior, to the mid to upper 30s in the urban centers.

Hoisted a Freeze Watch for coastal CT, southern Westchester, and
portions of NE NJ where the growing season continues into mid
November. Widespread frost development is likely as well,
perhaps even into the metro.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
The main highlight of the long term will be high pressure dominating
the weather pattern through the upcoming weekend. If the current
forecast verifies, the streak of 8 consecutive weekends with
measurable precipitation will end. The last fully dry weekend was
September 2-3, 2023.

Temperatures will start the period below normal with highs
struggling to rise above 50 degrees on Thursday. Another cold night
is expected Thursday night under mostly clear skies, light winds,
and a dry atmosphere. Model consensus lows range from the lower 30s
inland to middle and upper 30s closer to the coast.

Heights will begin rising on Thursday behind a departing shortwave
trough. Global models and ensemble means are all in good agreement
on the flow becoming zonal to end the week, likely continuing into
the weekend. There may be some amplification to the height field
towards the end of the weekend, but any troughing should remain over
the central states. This pattern will bring a warming trend and
continued dry weather through the weekend. Highs on Friday will be
close to normal (upper 50s) and then above normal this weekend
(lower 60s). Nighttime temperatures will also moderate with lows in
the upper 30s to the 40s over the weekend.

Modeling is in disagreement early next week with a progressive flow
across the CONUS. There are signals for an amplifying shortwave
tracking across the country during this time frame.
Deterministic runs are inconsistent on the evolution of a potential
low pressure and associated frontal system. NBM indicates increasing
chances for precip Monday night into Tuesday. Have capped PoPs off
at 40 percent (lower than the NBM) given the time range and
aforementioned uncertainty and inconsistencies in the modeling. Above
normal temperatures are favored to start next week.
-- End Changed Discussion --

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR this evening as high pressure retreats from the area. Low
pressure develops well offshore and passes to the east Wednesday.

MVFR ceilings and a period of light rain will be arriving across the
coastal terminals after 06z and continuing through Wednesday
afternoon. There could be pockets of IFR at the coast midday
Wednesday(mainly 14z-17z) but if it occurs would be rather brief.
Across the interior, MVFR likely to hold off until after 12z. There
will be pockets of light rain which may mix with a few snowflakes at
time at KSWF.

Expecting VFR to return Wed afternoon from W to E after 18z.

Winds NE-E wind around 10 kt will back to the NE tonight. N winds 10-
15kt Wed morning and then become NW Wednesday afternoon.


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

Amendments possible to adjust for timing of MVFR ceilings.

OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...

18z Wednesday: Becoming VFR by mid afternoon. N-NW winds G20kt.

Thursday through Sunday: VFR. S-SW winds G20kt Friday afternoon and
evening.

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

&&

.MARINE...
-- Changed Discussion --
Sub SCA conditions expected on all waters through this evening.
Wind and seas increase on the ocean overnight into Wed AM as a
frontal system passes nearby. Marginal SCA conds develop and
persist Wed thru Wed evening. Issued SCA for the ocean from 10Z
Wed thru 6Z Thu. Sub SCA conditions persist on non ocean waters
during this time.

Thereafter, a weak pressure gradient with high pressure in
control will lead to winds and seas below SCA levels Thursday.
The high moves offshore on Friday with an increasing SW flow
Friday afternoon. Marginal SCA gusts are possible on the ocean.
A similar set up exists on Saturday into Sunday with a modest SW
flow over the waters, but gusts should remain near 20 kt.
-- End Changed Discussion --

&&

.HYDROLOGY...
There are no hydrologic concerns through early next week.

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Astronomical tides will continue to subside through the middle of
the week. The latest blend of ESTOFS/ETSS/NYHOPS indicates water
levels will come close to minor benchmarks across the back bays of
Nassau County and across coastal Fairfield County with Wednesday
morning/afternoon high tide. A few of the most vulnerable locations
(Freeport, Reynolds Channel) may just touch during high tide
Wednesday morning. Have held off on additional coastal flood
statements since it looks marginal at this time.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Freeze Watch from late Wednesday night through Thursday
     morning for CTZ009>012.
NY...Freeze Watch from late Wednesday night through Thursday
     morning for NYZ071.
NJ...Freeze Watch from late Wednesday night through Thursday
     morning for NJZ104-106-108.
MARINE...Small Craft Advisory from 6 AM Wednesday to 2 AM EDT Thursday
     for ANZ350-353-355.
-- End Changed Discussion --

&&

$$

SYNOPSIS...DR/DS
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...DS
AVIATION...IRD
MARINE...DR/DS
HYDROLOGY...DR/DS
TIDES/COASTAL FLOODING...DS