000
FXUS61 KOKX 172322
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
622 PM EST Sun Dec 17 2023

.SYNOPSIS...
Strong low pressure along the Carolina coast this evening
approaches form the south tonight and passes through the region
during Monday. The low tracks north of the area Monday night.
Low pressure moves away from the area on Tuesday with high
pressure building in. High pressure will remain in control
through next weekend.

&&

.NEAR TERM /THROUGH MONDAY/...
Scattered areas of light rain have become more widespread this
evening as moisture levels increase, and in response to the
approach of a northern stream upper trough. Rainfall then
becomes categorical later tonight and overnight as deepening low
pressure along the southeastern coast this evening approaches
the region from the south. Timing and track of the low remain
fairly consistent with the previous forecast. With the low
continuing to rapidly deepen tonight and a strong low level jet
developing on the eastern side of the low, a period of moderate
to heavy rainfall is expected late tonight into Monday morning.
Some of the highest rainfall totals are expected across portions
of northeastern New Jersey into the lower Hudson Valley, and
even into southwestern Connecticut (Fairfield County) with
strong southeasterly flow enhancing lift on the upslope sides of
the higher terrain. Rainfall totals have increased slightly
across these areas. Weak elevated instability, especially late
tonight into Monday morning, will also enhance rainfall, as
isolated thunder remains possible. A flood Watch remains in
effect tonight through Monday afternoon.

A period of high winds and strong gust also remain likely late
tonight into early Monday morning as a strong low level jet of
60-85kt moves over the eastern regions. And a High Wind Warning
remains in effect for the coastal locations. With a slightly
more western track of the low and winds gusts possibly reaching
advisory levels farther west and north, have expanded the winds
advisory to include Eastern Bergen, Eastern Essex, and Eastern
Union Counties. While the period of the strongest winds and
gusts will be a few hours late tonight into early Monday
morning, the timing of the Warning and Advisory remain as
initially issued.

&&

.SHORT TERM /MONDAY NIGHT/...
The low will be north of the area by Monday night with a brief
break in precipitation. Wrap around moisture in the back side
of the low will maintain chance and slight chance probabilities
Monday night. With some colder air wrapping into the northwest
sections a few snow showers and flurries will be possible. There
may even be slight coating of snow in the higher terrain of
Western Orange County.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Upper level low over the eastern Great Lakes region will weaken
into a trough as it moves toward the forecast area. A weak area
of low pressure looks to form along the frontal boundary
offshore, and a blocking pattern will then set up as the trough
becomes an upper level low once again and will interact with the
weak surface low offshore, becoming vertically stacked by the
middle of the week. With a blocked pattern over the region, the
surface high that builds in late Tuesday into Tuesday night will
remain over the area through next weekend. The only chance for
any precipitation for this time frame is during the day on
Tuesday. This will be due to the trough aloft and one at the
surface that will move through. These features may provide
enough lift for some precipitation, however any precipitation
will be light. It will be cold enough well inland Tuesday
morning for some snow flakes to fall, or snow mixed with rain,
but little if any accumulation is expected.

The area will be on the eastern side of the high during much of the
week, with a northwest to northerly flow for much time. This will
lead to seasonable temperatures with highs in the 40s.

&&

.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
HIGH IMPACT AVIATION EVENT TONIGHT INTO MONDAY...

Deepening low pressure tracks up the East Coast through Monday.

MVFR to IFR conditions across the area terminals through this
afternoon/evening. Widespread IFR tonight, possibly LIFR, with
steady rain developing toward 00Z Mon.

Easterly flow around 10 to 15 kt with gusts up to 20 kt through
this evening. Winds steadily ramp up tonight after 03Z Monday,
with strongest winds after 06Z Monday. SE winds increasing to
20-30kt G35-55kt, strongest along the coast. Slow improvement
late Monday morning through the afternoon, with winds gradually
decreasing in the afternoon and into the evening. Winds become
S/SW Monday morning then shift around to the west after 22z,
with showers also tapering off.

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

Gusts through this afternoon and early evening may be more
occasional than frequent.

Isolated 50+ kt gusts late tonight into Monday morning, especially
at KJFK and KLGA.

OUTLOOK FOR 20Z MONDAY THROUGH FRIDAY...

Monday: IFR, possibly LIFR in rain early. Isolated thunderstorm
possible in the morning. LLWS through the morning. SE winds
20-30kt gusting 35-50 kt before 15Z, strongest along the coast,
becoming S then SW to W diminishing late Monday afternoon and
night.

Tuesday: Chance of flurries mainly north and west of the NYC
terminals early, then a few rain or snow showers possible along the
coast during the afternoon. MVFR, possibly IFR, especially in any
snow showers. WNW G20-25kt in the afternoon.

Wednesday through Friday: VFR.

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

&&

.MARINE...
With winds, gusts, and seas expected to increase tonight,
especially late tonight, have begun the Storm Warning for all
the forecast waters with the evening issuance. The strongest
winds and gusts will likely continue into Monday morning before
diminishing rather quickly from west to east midday through
Monday afternoon. The highest winds will likely be after 100 AM
through about 1000 AM Monday. Once the Storm Force gusts
diminish there will be a brief period of gale force gusts
before winds diminish to SCA levels Monday evening, wind winds
falling below advisory levels late Monday night, ending by
Tuesday morning. However, very high ocean seas will remain
through Monday night.

An extended period of SCA is expected on the ocean waters
through at least the end of the week as long period swells from
an offshore storm keep waves elevated. Wave heights on the ocean
will range from 8 to 13 ft Tuesday morning will slowly diminish
through Thursday morning to around 5 ft. They then may build
again slowly through the end of the week.

Winds should remain below SCA criteria, except for Tuesday on the
ocean waters as a tight pressure gradient weakens with high pressure
building in.

&&

.HYDROLOGY...
A total of 2 to nearly 5 inches of rainfall is expected through
Monday afternoon, with most of this falling from late tonight through
Monday morning. Locally higher amounts, as much as 5 to 6
inches, are possible across portions of northeastern New Jersey,
into the Lower Hudson Valley, and possibly into portions of
Southwestern Connecticut (Fairfield County). The location of the
highest amounts will be dependent on the track of the low, and
will be more likely on the upslope sides of higher terrain. With
flooding of fast responding streams, possibly reaching moderate
flooding benchmarks, and flooding of poor drainage and urban
areas, and localized to scattered flash flooding becoming more
likely, the Flood Watch remains in effect tonight through Monday
afternoon. A few of the faster responding stream of northeastern
New Jersey may even reach major flooding benchmarks.

Afterwards, no hydrologic impacts expected through next weekend.

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Coastal flood warnings continue for southern Queens, southern and eastern portions of LI and coastal CT, and expanded for NE NJ as widespread moderate coastal flooding is likely with the daytime high tide cycle on Monday. This includes the tidally affected rivers, particularly Hudson and Hackensack rivers, where the surge is favored to be forced upstream by the strong southerly flow. There is potential for locally major flood thresholds to be reached for southern Queens, SW LI and twin forks, if windshift occurs near or after the time of high tide. Elsewhere minor to locally moderate coastal flood potential exists for NE LI and northern portions of NYC. Peak surge of 3 1/2 to 5 ft will likely be between high tidal cycles Monday morning. A later timing of windshift closer to the early Monday afternoon time of high tide will aid potential for major flood thresholds to be reached or exceeded for the most vulnerable southern Queens, SW and E LI portions of the area. This will likely not be evident until the time of high tide is approaching. Forecast is a blend of 75th percentile of PETSS, Stevens, and deterministic ESTOFS. Heavy rainfall and/or runoff coinciding with the Monday afternoon high tides will exacerbate street and property flooding issues along the coast and tidally affected rivers. Along the ocean beachfront, potential exists for 12-16 ft breakers Sunday overnight into Monday (8-12ft for NYC beachfront), which combined with elevated water levels, will likely result in widespread dune erosion and scattered overwashes. Finally, minor coastal flooding possible with tonight`s high tide mainly for southern Queens, SW LI and coastal Westchester and SW CT.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Flood Watch through Monday afternoon for CTZ005>007-009>011. Wind Advisory from midnight tonight to noon EST Monday for CTZ005>007. High Wind Warning from midnight tonight to noon EST Monday for CTZ008>012. Coastal Flood Warning from 10 PM this evening to 6 PM EST Monday for CTZ009>012. NY...Flood Watch through Monday afternoon for NYZ067>075-176-178. Wind Advisory from midnight tonight to noon EST Monday for NYZ071>074. High Wind Warning from midnight tonight to noon EST Monday for NYZ075-078>081-176>179. Coastal Flood Warning from 10 PM this evening to 6 PM EST Monday for NYZ071. Coastal Flood Warning from 10 AM to 4 PM EST Monday for NYZ074- 075. Coastal Flood Advisory from 10 PM this evening to 6 PM EST Monday for NYZ072-073-078-176-177. Coastal Flood Warning from 11 PM this evening to 6 PM EST Monday for NYZ079-081. Coastal Flood Warning until 6 PM EST Monday for NYZ080-178-179. NJ...Flood Watch through Monday afternoon for NJZ002-004-006- 103>108. Wind Advisory from midnight tonight to noon EST Monday for NJZ006-104-106-108. Coastal Flood Warning from 10 AM to 4 PM EST Monday for NJZ006- 104-106-108. MARINE...Storm Warning until 1 PM EST Monday for ANZ331-332-335-338-340- 345-350-353-355.
-- End Changed Discussion --
&& $$ SYNOPSIS...JP/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...JP AVIATION...20 MARINE...JP/MET HYDROLOGY...JP/MET TIDES/COASTAL FLOODING...