365
FXUS61 KOKX 161031
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
531 AM EST Mon Dec 16 2024
.SYNOPSIS...
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A weakening disturbance passes through the area today, followed
by a quick moving frontal system tonight into Tuesday morning.
High pressure will then briefly move in Tuesday night into early
Wednesday. Low pressure passes to the north Wednesday night,
sending another frontal system across the area. High pressure
returns for the end of the week.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Winter weather advisories remain up across the interior through
11 AM. These will likely be taken down before then, but a
buffer is in place to account for some uncertainty with how
quickly the low-level cold air erodes in valley locations.
A weakening upper level disturbance and weak surface low will
move across the area this morning. With surface high pressure
centered east of the New England coast combined with an E/SE
surface flow and a strengthening southerly LLJ will continue to
gradually warm the low levels below 85H. This will allow for a
transition to all rain over the next couple of hours. However,
some trapped low-level cold air across the interior and a
somewhat slower response of ground temps due to the recent cold
stretch, will allow for some freezing rain this morning. Even a
northerly flow helped to bring some colder air down the
Connecticut River Valley, with freezing rain reported in New
Haven area. In addition, there have been reports of 2 to 3
inches of snowfall across portions of the Lower Hudson Valley
and SW interior CT.
The area of heaviest precipitation will shift to the east later
this morning. However, while mid level dry air works into the
region, a southerly LLJ will help to maintain pockets of light
rain and/or drizzle into this evening. Temperatures will
continue to gradually rise into this afternoon, topping out in
the lower 40s inland, to around 50 at the coast.
Shortwave ridging this evening may for a time shut down the
rain, but this will be short-lived as a negatively tilted upper
trough tracks across the Great Lakes sending a warm front into
the area later tonight with another round of steady rain.
Another southerly low-level jet will work through the area
overnight, likely enhancing rainfall across LI and southern CT.
Rainfall amounts of 0.25-0.50" are expected with some locally
higher amounts possible. Temperatures will gradually rise into
the upper 40s and lower 50s overnight.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY/...
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Rain ahead of a cold front will exit to the east by the end of
the morning Tuesday as a cold front passes through the area.
Expect gusty W/SW winds up to 20 mph with clearing skies. It
will be very warm Tuesday with high in the mid to upper 50s,
about 10-12 degrees above normal.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
An active pattern in place towards mid and through late week. Taking
a look at 250mb, strong upper jet streak north of the region Tuesday
night into Wednesday. This moves across the local area Wednesday
night into Thursday. Then, jet streak dives farther south Friday
into next weekend, setting up south of the region.
At 500mb, the upper pattern transitions from zonal Tuesday night to
a trough Wednesday night into Thursday. Then, briefly quasi-zonal
Thursday night before a longer wavelength trough sets up in the
region Friday into next weekend.
Surface pressure gradient not that tight Tuesday night through
Friday night. The pressure gradient tightens next weekend with
offshore developing low pressure and strengthening high pressure
moving in from the west. There is possibility for low and high
pressure to strengthen more than forecast for next weekend.
Regarding temperatures, overall decreasing trend. Starting out above
normal with temperatures towards midweek, then closer to normal
Thursday and Thursday night, and then getting more below normal
thereafter. The coldest airmass of the entire forecast period going
out through the next week is forecast for next weekend when forecast
highs once again will stay in the 30s.
Regarding precipitation, mainly a rain event for Wednesday into
early Thursday. Generally around 0.5 to 0.75 inch of rain is
forecast. Only wintry precipitation potential with this system is on
the backside with cold air advection late Wednesday night into early
Thursday morning for portions of the interior. However, drier air
advecting in will really limit the precipitation chances overall.
Potential for more snow Friday into the weekend. One low is
approaching from the Great Lakes and one low is far offshore.
Lows are not too strong. Chances for precipitation mainly in the
form of snow are forecast, but stays mostly under 50 percent. The
models are not really showing any significant phasing or strength
of low pressure. Might be more occasional snow shower activity
for Friday into next weekend.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
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Strong high pressure continues to push east of the New England
coast. A disturbance is moving through and will exit by midday. A
warm front then moves in this evening into tonight.
Most ceilings have gone down to MVFR in rain. Ceilings may lower to
IFR by mid-morning. Brief periods of LIFR are possible this morning.
Rain may take a break after midday into the evening with only a few
light showers expected which have be shown in TAFs using PROB30s. AT
the same time, ceilings will likely hover between MVFR and IFR.
MVFR/IFR fog is possible for terminals north and west of NYC late
morning into early afternoon. Rain returns late this evening into
tonight. Ceilings will likely drop to IFR/LIFR tonight with rain.
Brief periods of LIFR will again be possible tonight.
KSWF and KHPN are currently the only terminals with mixed precip.
Snow may continue at KSWF until 11Z, then switch to a rain-snow mix
and/or with freezing rain. THen later this morning transition to
rain. As for KHPN, a rain-snow mix is possible until 12Z, where a
transition to total rain is expected.
Winds are light and variable at many terminals this morning with
other terminals N/NE 5-8 kt. Winds this afternoon will be E/ESE
around 10 kts. Tonight, winds pick up in speed 10-15 kts with gusts
around 20 kts after 4Z. Wind directions turn south at 00Z tomorrow
then SW by 9Z tomorrow.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
MVFR timing may be off by 1-3 hours. Timing of IFR Monday morning
may be off by 1-3 hours.
OUTLOOK FOR 09Z SUNDAY THROUGH THURSDAY...
Monday Night-Tuesday: IFR and rain. The rain ends by the afternoon
with conditions returning to VFR. S-SW gusts 15-20 kt late Monday
night into Tuesday morning, becoming W Tues afternoon.
Wednesday-Wednesday night: VFR early becoming MVFR-IFR with rain by
evening into the night. NW gusts 15-20 kt possible late Wednesday
night.
Thursday: Mainly VFR. NW gusts 15-25kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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A southerly LLJ today will bring winds and seas up a bit sooner
today with SCA conditions forecast to develop on the ocean
waters by early afternoon. Advisory level winds then expand
across the remainder of the waters overnight with gusts getting
as high as 30 kt on the ocean late tonight following a warm
frontal passage. Winds and seas will then gradually come down on
the from west to east following a cold frontal passage Tuesday
morning. However, seas 5 to 8 ft on the ocean Tuesday morning
will be slow to fall through the day.
The ocean is forecast to have lingering SCA level seas Tuesday night
as well as Wednesday night through Thursday. In addition, some
eastern portions of the ocean could have SCA seas Thursday night.
Sub-SCA forecast for ocean on Friday. Some eastern portions of the
ocean could again have SCA seas Friday night.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through next weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Winter Weather Advisory until 11 AM EST this morning for
CTZ005>008.
NY...Winter Weather Advisory until 11 AM EST this morning for
NYZ067>070.
NJ...Winter Weather Advisory until 11 AM EST this morning for
NJZ002.
MARINE...Small Craft Advisory from midnight tonight to noon EST Tuesday
for ANZ331-332-335-340-345.
Small Craft Advisory from midnight tonight to 6 AM EST Tuesday
for ANZ338.
Small Craft Advisory from 1 PM this afternoon to 6 PM EST
Tuesday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JM
AVIATION...BR
MARINE...JM/DW
HYDROLOGY...DW