000
FXUS61 KOKX 212009
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
309 PM EST Thu Dec 21 2023
.SYNOPSIS...
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High pressure anchored north of the area will be in control for the
remainder of the week.High pressure weakens on Saturday ahead
of unorganized low pressure Saturday night into Sunday morning.
High pressure reestablishes itself Sunday afternoon into Monday
before moving offshore on Tuesday. Low pressure and its
associated frontal system will likely impact the area Tuesday
night into the middle of next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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A cold front has lead to breezy north winds which will lessen as we
go into tonight due to a weakening pressure gradient. High pressure
to the north will help reinforce colder air in the region tonight
with clear skies. Lows are expected to be in the low-20s/upper-teens
for most. The NYC metro will be be drop into the upper-20s while far
interior areas may see mid-teens. These temperatures are only a few
degrees to 5 degrees below normal, but still some of the coldest we
have seen thus far this season.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
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Look for the drier stretch of weather to continue with high pressure
spreading down into New England. After plenty of sunshine, some high
clouds begin to streak during the afternoon and evening as the 500
mb ridge axis moves over the area. Temperatures will struggle to get
out of the 30s, despite sunshine.
Clouds begin to increase Friday night in advance of an approaching
mid level shortwave. The timing of the advance of mid level clouds
will ultimately determine how much radiational cooling takes place,
and thus how low temperatures ultimately get. Either way, a
seasonably cold night takes place with lows in the 20s to lower 30s.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
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*Key Points*
- Mainly dry conditions expected this weekend through Christmas Day.
- Gradual warming trend this weekend through the middle of next week.
- A rain event is becoming more likely Tuesday night into Wednesday.
There remains uncertainty on exact timing and rainfall amounts. The
system at this time does not appear to bring significant impacts to
the region.
Weak middle level ridging is expected to move offshore on Saturday.
A broad shortwave quickly approaches Saturday night into early
Sunday. This will help weaken the surface high pressure and allow a
disorganized low to pass across New England by Sunday morning and
then quickly offshore thereafter. The modeling continues to hint at
some very light QPF amounts under weak lift and limited moisture. It
is not out of the question for a few locations to see some light
precip Saturday night into early Sunday morning. Thermal profiles
are marginal for any wintry precip and soundings indicate limited
ice nucleation aloft. Temperatures should largely stay above
freezing due to no fresh cold air source, light SW flow, and
increasing clouds late Saturday into Saturday night. However, cannot
completely rule out portions of western Orange County getting close
to freezing, so a localized occurrence of light freezing rain cannot
be ruled out. Probabilities are very low and feel its best to watch
trends in the next day before including mention of freezing rain in
Orange County in the HWO. Otherwise, any precip that falls elsewhere
will be in the form of sprinkles or light rain showers. It should be
emphasized that probabilities for measurable precip remain very low,
generally 20 percent. The system moves east of the area later Sunday
with high pressure reestablishing itself into early next week.
Ridging builds over the eastern seaboard Monday and then moves
offshore on Tuesday ahead of an amplifying shortwave trough over the
central states. The parent low tracks towards the Great Lakes on
Tuesday with its associated frontal system approaching through
Tuesday night. The global deterministic guidance and ensembles
differ on whether or not there will be secondary development along
the Middle Atlantic/northeast on Wednesday. NBM probabilities for
greater than 1 inch of rain in any 12 hour period with this event
are around 10 percent and it has been relatively similar over the
last few cycles. This would give some confidence that impacts from
rainfall should be limited with this event. The models also have
timing differences that are a result on how the tough evolves aloft.
Used NBM likely PoPs late Tuesday night into Wednesday. There is
high confidence that any precip will be in the form of rain with the
parent low tracking up into the Great Lakes, driving warmer air up
into the northeast. Differences on the models increase further with
the evolution of the upper trough. Some of the global guidance hints
at the trough becoming an upper/closed low Thursday or by the end of
the week, which could start a cooling trend towards the end of the
year.-- End Changed Discussion --
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
High pressure remains in control.
VFR. N winds 10-15kt with gusts around 20kt through the afternoon.
Winds then diminish this evening with light NE winds for Friday
morning before becoming variable in direction in the afternoon.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts might be only occasional.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday PM through Saturday: VFR.
Saturday night-Sunday: VFR, with possible MVFR at times.
Monday: VFR.
Tuesday: Mostly VFR. Chance of rain and sub-VFR late
day/nighttime.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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A Small Craft Advisory remains in effect through Thursday night for
the ocean waters for waves 5-7 feet. Wind gusts have remained below
25 kts.
Lingering E-ESE swells Friday morning may lead to 5 ft seas over the
ocean. The swells look to subside through Friday with sub-SCA
conditions likely on all waters Friday night.
The pressure gradient over the waters will remain weak this weekend
through next Tuesday leading to conditions below SCA levels.-- End Changed Discussion --
&&
.HYDROLOGY...
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There is still lingering flooding along the Passaic River (warnings
handled by WFO PHI), Housatonic River (warnings handled by WFO ALY),
and Connecticut River (warnings handled by WFO BOX). Otherwise, no
additional hydrologic impacts are expected through Tuesday.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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A long period E swell may bring water levels close to minor flooding
benchmarks for the south shore back bays of Nassau for early Friday
morning high tide. Guidance has continue to trend lower and it
appears water levels should remain below minor benchmarks.
Statements are not anticipated at this time.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until noon EST Friday for ANZ350-353-355.
&&
$$
SYNOPSIS...BR/DS
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...DS
AVIATION...JC
MARINE...BR/DS
HYDROLOGY...BR/DS
TIDES/COASTAL FLOODING...DS