415
FXUS61 KOKX 062014
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
314 PM EST Fri Dec 6 2024
.SYNOPSIS...
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High pressure to the southwest of the area will remain in
control through Saturday. A fast moving low pressure passes to
the north and east Saturday night into Sunday. Another frontal
system may impact the area Monday into Monday night. A cold
front approaches Tuesday night and passes Wednesday night. High
pressure returns thereafter.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH SATURDAY/...
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The Tri-State area remains between high pressure over the
south-central states and deep low pressure over southeastern
Canada. The pressure gradient will be much weaker than Thursday
night. Most gusts should end this evening, but the NYC metro and
coastal locations could remain mixed enough to support some
gusts 20-25 mph tonight.
The axis of a large upper trough that has been over the region
will shift to the east tonight. A vortmax will pass overhead
this evening, which likely brings an increase in mid clouds. The
clouds should diminish in coverage towards midnight leading to
mostly clear to partly cloudy skies early Saturday morning.
Temperatures tonight should bottom out in the upper teens to low
20s inland and middle to upper 20s elsewhere.
We will still lie on the northeast periphery of the high pressure
on Saturday, but the gradient is much weaker. A few gusts 15-20
mph are possible, especially near the coast. Mostly clear
conditions are expected into the early afternoon. Clouds will
increase late in the day ahead of the next shortwave diving out
of southern Canada. Highs will also be a bit warmer than Friday,
but still be 5-8 degrees below normal in the upper 30s inland
and lower 40s near the coast.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
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The aforementioned shortwave that dives out of southern Canada
on Saturday will pass to our north Saturday night into Sunday.
Low pressure associated with the shortwave will move near the
Great Lakes Saturday evening and then track across northern New
England on Sunday.
A warm front will likely set up north of the area Saturday
evening. Warm advection/isentropic lift should help lower and
thicken clouds from northwest to southeast Saturday night. The
lift is weak, but most of the model guidance signals potential
for at least a broken band of light precip overnight. The best
potential for this precip appears to be from the Lower Hudson
Valley southeastward towards southern Connecticut and Long
Island. Thermal profiles are cold enough initially with wet
bulbing for some light snow. However, there may be a warm nose
around 5-7kft which may allow for some sleet as the precip is
coming to end early Sunday morning. Warmer surface temperatures
across the forks of Long Island should bring a mix of rain/snow
or even plain rain. Southeast CT should stay all light snow with
the colder air taking longer to dislodge across this area.
PoPs are a bit higher compared to the previous forecast, but
have remained just below the NBM as dry subcloud and weak lift
should prevent the precip from being widespread. Liquid amounts
are just a few hundredths, especially eastern part of the area.
Any snow accumulation will be light, but some locations could
see a dusting across southeastern CT and maybe eastern Long
Island where it stays cold enough.
The system quickly passes east and any precip should end around
or shortly after day break. The boundary likely stays north of
the area through the rest of Sunday. The air mass will be much
milder under a west flow. Skies should become mostly sunny by
afternoon with highs near or slight above normal in the
mid/upper 40s to around 50 at the coast.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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Key Points:
* Cold & dry Sunday night.
* Rainfall on Monday. Tapers Monday night.
* Widespread rainfall Tuesday night into Wednesday evening with
warmer temperatures. Brief snowfall possible Wednesday night
as a cold front passes.
* Breezy Wednesday into Thursday.
* Much colder Thursday into Friday.
A weak ridge builds aloft into Sunday night as surface high
pressure passes well to the south. This leads to mostly clear
skies Sunday night under a light westerly flow. As a result,
Sunday night will be dry and cool with lows around the mid-30s
to mid-20s. This will be around or just below average.
Southern and northern stream jets start to phase to the west
on Monday and begin to strengthen Monday night. Locally, a
ridge remains aloft on Monday into Monday night with a shortwave
trough embedded in the longwave ridge that passes Monday into
Monday night. This brings a wave of low pressure at the surface
through the region. The warm front associated with this low,
which will approach from the southwest, will push into the
region mid/late morning into midday Monday, leading to
increasing temperatures and increasing rain chances. The arrival
timing of the low has been pushed back somewhat, meaning precip
may not start until well after sunrise. So previously
forecasted freezing rain for some interior areas Monday morning
may no longer occur. Instead, this event will be all rain.
Models are in good agreement on the timing. Showers will be
widespread midday into the evening before the low exits to the
northeast and rain tapers Monday night. Highs will be low-40s to
low- 50s Monday. Monday night will be warmer in the mid-30s to
low-40s.
A longwave trough aloft amplifies over the central U.S. Tuesday
as it slowly pushes eastward. A low that develops over the Gulf
States tracks up Appalachia and to the northeast Tuesday night
into Wednesday. This will be aided by a strengthening jet stream
oriented SW to NE that moves over the region on Wednesday and
also aided by a further deepening of a longwave trough aloft
that inches closer into Wednesday. This will lead to another
chance for widespread rain showers. Models currently have precip
starting Tuesday night as a warm front pushes in ahead of the
surface low`s arrival. Rain may continue through the day on
Wednesday, picking up in intensity ahead of the cold front`s
arrival due to increasing southerly winds aiding in more warm
air advection and surface temperatures well above average aiding
in more efficient rainfall. Highs Wednesday will be in the
low-50s to upper-50s. Higher PWATs will also be advected in
ahead of the cold front, maxing out around 1.1-1.2" for western
locations and eastern locations maxing out around 1.3-1.5". This
is around the maximum moving average per SPC`s Sounding
Climatology Page. Some showers may be locally moderate to heavy,
at times. Most global guidance currently hints at widespread
1-2" QPF over 24 hours.
The cold front is currently progged by models to be sometime
Wednesday evening or early Wednesday night as the surface low
passes to our northeast. Cold air advection is expected to be
very strong behind the cold front, aided by a highly amplified
trough that moves in Wednesday night into Thursday. This may
lead to precipitation getting sharply cut off along the front`s
passage with the clouds clearing. However, should locations be
cold enough before FROPA, they may be able to cool quickly
enough to see some flakes before precipitation cuts off. This is
not expected to last very long, however, so if snowfall does
occur, it will not occur for a long enough time to lead to any
significant accumulation. However, models still differ a little
on the FROPA timing, so this is still subject to change.
A strong LLJ may develop prior to and after FROPA, which may lead
to breezy winds Wednesday into Thursday. Currently forecasting
winds Wednesday into early Thursday to peak around 10-15 mph
gusting up to 20-30 mph. Winds will be southerly following a
warm front passage early Wednesday then turn northwest following
FROPA Wednesday night.
Heights start to rise aloft late Thursday into Friday as surface
high pressure moves in from the southwest and centers over the
region on Friday. Thursday and Friday will be cold with highs in the
mid-30s to low-40s.-- End Changed Discussion --
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
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The terminals will remain between strong low pressure to the
northeast and high pressure to the southwest.
VFR through the TAF period.
Gusty W-WNW winds expected through a good part the TAF period.
Sustained speeds 15-20 kt with gusts 25-30 kt are likely this
evening. Winds are expected to substantially diminish tonight,
especially away from the coast. Additional gusts are possible
Saturday, especially through midday.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
No unscheduled amendments are expected.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday. VFR. W wind gusts 15-20 kt.
Sunday. VFR. SW wind gusts 15-20 kt.
Monday: MVFR to IFR at times in rain. Possible wintry mix for
KSWF early Monday.
Tuesday: Increasing chances of rain day into night, expected to
occur at night. MVFR to IFR at times.
Wednesday: IFR or lower in rain.
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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SCA conditions will continue on the ocean through Saturday
morning. Winds on the Sound, Bays, and Harbor will weaken below
SCA levels tonight, so will expire the SCA at 1 am. The SCA on
the ocean runs through noon Saturday. Winds and seas by that
time should be below SCA levels and will likely remain through
Saturday evening. Increasing SW winds late Saturday night will
bring another period of SCA conditions into Sunday, likely
lasting on the ocean into Sunday night, especially east of
Moriches Inlet, due to lingering elevated seas. Conditions are
then expected to be below SCA levels until a frontal system
approaches Tuesday into Wednesday which will lead to elevated
winds and seas.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic impacts are anticipated through the middle of next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 1 AM EST Saturday for ANZ331-332-
335-338-340-345.
Small Craft Advisory until noon EST Saturday for ANZ350-353-
355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BR/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BR
AVIATION...IRD
MARINE...BR/DS
HYDROLOGY...BR/DS