679
FXUS61 KOKX 050607
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
107 AM EST Thu Dec 5 2024
.SYNOPSIS...
A strong frontal system will move across through early
Thursday. The region will then lie between low pressure over the
Canadian Maritimes and high pressure over the Central states
Thursday night through Friday. The high will then slowly move
off the Southeast coast this weekend as a warm front passes well
to the north. Another warm front will approach and pass through
on Monday. A slow moving cold front will then approach from
the west from Tuesday into Wednesday.
&&
.NEAR TERM /THROUGH TODAY/...
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As precipitation picks up in intensity for eastern sections,
areas which were receiving just plain rain have mixed in with
wet snow in some spots via evaporative cooling as freezing
levels fall a bit, at least momentarily. Cameras up north across
NE Fairfield and N New Haven counties indicate light to moderate
snow has fallen and has resulted in snow covered secondary and
tertiary roadways. Maintaining localized 1 to 2 inch amounts,
mainly on colder surfaces in NW interior CT, especially getting
closer to I84. Eventually the steadier precip across theses
areas is expected to get further east for the predawn hours.
Therefore holding current thinking that northern Fairfield, New
Haven, and extreme NW Middlesex zones should fall short of adv
level snow. Thus no changes anticipated for the next several
hours as radar trends are as expected. Precip is noticeably
lighter and spotty back to the west over the Hudson Valley and
NE NJ and NYC where spotty light rain / snow will continue
overnight. Temps here should stay a touch above freezing so not
anticipating icing / freezing issues at this point with respect
to travel in these areas. Previous discussion follows.
A potent middle level vort max will dive southeastward from the
Eastern Great Lakes region, through PA and into the northeast/
Middle Atlantic coast by Thursday morning. The associated
closed upper low approaches and draws closer overnight and
passes over the area on Thursday. The system will bring a
strong frontal system overnight, with the warm front lifting
over the area first and to the north ahead of the main cold
front passage through early Thursday.
Most of the precip will be along and ahead of the warm front,
with moderate precip shifting ENE overnight. The precip
coverage will likely be more scattered across NE NJ and the
Lower Hudson Valley for much of the overnight, but become more
widespread early Thursday morning as the potent shortwave
provides more enhanced lift just ahead and along a cold front.
The precip should then begin tapering off from west to east
after day break as the strong cold front sweeps through the
area. Many of the CAMs are hinting at a convective line
accompanying the front in the morning, which may bring a brief
enhancement before the precip ends.
Precipitation Types and Amounts...The increasing SW flow will
bring in warmer air which will allow the precip to be mainly
rain across the NYC metro, Long Island and south central and
southeast Connecticut. The interior of the Lower Hudson Valley,
southwest Connecticut, and NE New Jersey will be mostly snow.
There may be some wet snow flakes mixed in near the Hudson
River Corridor/NYC metro and then as the potential convective
line moves through with the cold front early in the morning.
There has not been much change with regards to snowfall
accumulation with less than an inch across interior Lower Hudson
Valley to around 1-2 inches across interior Southwest
Connecticut (northern Fairfield and northern New Haven
counties). Some higher elevations in northern Fairfield and
northern New Haven could see locally higher around 3 inches.
Will mention potential for slick travel in the HWO for these
zones. Otherwise, little to no snow accumulation is expected
outside of the aforementioned areas. Liquid equivalents range
from around a tenth west to one half to three quarters eastern
Long Island and southeast Connecticut.
Winds...No changes made to the wind advisory headline Thursday
into Thursday evening. S-SW flow strengthens tonight with
potential gusts 25 to 35 mph, especially along the coast, where
even 40-45 mph could be reached. Winds will pick up quickly
with the cold front passage Thursday morning. A steep pressure
gradient, a well mixed boundary layer, and strong cold advection
will increase westerly winds to 20-30 mph with gusts 45 to 50
mph. The strongest gusts are most likely to occur in the
afternoon and early evening.
There will be improving sky conditions behind the front, but
varying levels of stratocu are likely in the cold advection
regime. There may also be some flurries or even a few snow
showers in the afternoon. Daytime highs will be in the upper
30s inland to the lower 40s near the coast. Some areas may see
their max temp for the day occur ahead of the front with
temperatures remaining colder for the rest of the day. The
strong winds will make it feel colder, with wind chills only
in the 20s.-- End Changed Discussion --
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
Strong winds continue Thursday evening as the region will lie
between deep low pressure over the Maritimes and high pressure
over the central states. The closed upper low and trough axis
push offshore, but there will be another dry front/surface
trough that passes late Thursday night and early Friday morning.
This will reinforce the cold air and bring in even drier dew
points. The low level winds will weaken however and we should be
below advisory levels by late Thursday evening. The end time of
the Advisory looks good (10pm). Wind gusts 25-35 mph, strongest
near the coast, continue with temperatures falling into the 20s
for much. Wind chills look to be in the teens by early Friday
morning, with potential for a few spots around 10 inland. Any
lingering flurries Thursday evening should end after sundown.
Breezy and cold conditions continue on Friday. NW gusts look to
reach 25-30 mph with temperatures only in the low to middle 30s.
There should be some stratocu for at least partly cloudy skies, but
no precipitation is expected at this time.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
The large upper trough that has been responsible for recent cold
wx will finally slide east this weekend, replaced by broad
ridging quickly propagating over from the Western states Sunday
and Monday. As this ridging slides east, deep layer SW flow
ahead of an amplifying trough over the nation`s mid section will
then take hold going into mid next week. Temps on Sat 5-8
degrees below avg on Sat will quickly moderate to slightly above
avg on Sunday as a warm front passes to the north and sfc high
pressure moves to the SE coast. As another warm front moves
directly toward the area and on Mon and lifts through by
evening, temps should modify further above normal on Mon, with
highs in the upper 40s/lower 50s, and a little warmer than that
for Mon-Tue with highs reaching the lower/mid 50s.
With the approach of the warm front on Mon, expect rain to become
likely through the day. If precip arrives early enough Mon morning
there is a slight chance of precip beginning briefly as -FZRA in the
valleys of Orange County.
With the area in the warm sector ahead of a slow moving cold front
aligned with the flow aloft going into mid week, capped any likely
or greater NBM PoP to 50 percent through the rest of the fcst
period. Timing of the front is uncertain, with the faster ECMWF
bringing it through before daybreak Wed, and the slower GFS
lagging until Wed afternoon out east.
Chance PoP continues into Wed and Wed night as fcst uncertainty
increases further regarding timing and track of a low coming out of
the Gulf States. Faster GFS starts bringing significant precip as
early as Wed night-Thu, while the ECMWF holds off until beyond
the fcst period.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
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A cold front passes through 11-13z this morning.
Mostly MVFR ahead of the cold front with rain, snow, and a
mixture falling at times. Some IFR possible mainly east of the
city terminals due to cigs, but IFR vsbys possible in KSWF and
maybe even KHPN due to snow. KSWF total snowfall of 1/2 to 1
inch. Precipitation ends with the passage of the cold front by
mid morning, and conditions quickly improve to VFR.
Winds ahead of the cold front SW 15-20kt with gusts 25-30kt.
Occasional gusts 35-40kt for the coastal terminals. Behind the cold
front, west winds around 25kt with gusts up to around 40kt,
diminishing this evening but remaining gusty.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Amendments for precip type possible, highest confidence in precip
type is at KJFK. Precip still possible from 07-08z until 12-13z.
Tempo VFR conds possible now through the cold front passage.
Sustained wind speeds and gusts may vary widely tonight within a
short amount of time. Peak gust around 40kt possible ahead of the
cold front, then as high as 42-45kt late morning to afternoon.
OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
Late tonight: VFR. W winds gust around 30kt.
Friday: VFR. NW winds G25-30kt.
Saturday - Sunday: VFR.
Monday: MVFR with a chance of rain showers, IFR in the afternoon
with rain showers.
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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Increasing SW winds are expected overnight ahead of a strong
frontal system. Gales currently on the ocean become more
widespread across the other waters for the remainder of the
overnight, and then into Thursday morning. Gales on the non
ocean waters may be marginal initially, but become widespread
and frequent Thursday morning behind the cold front passage.
Gales will then continue through Thursday evening before slowly
diminishing on the Sound, Harbor and Bays towards early Friday
morning. Rough conditions are likely due to elevated seas with
10-14 ft seas on the ocean and 4-7 ft on the Sound on Thursday.
Low water levels are possible near shore during the daytime low
tide on Thursday. Water levels may fall to around -2 feet MLLW.
Rough conditions will Fri into Fri evening with SCA winds on
all waters. Ocean seas will subside through the day, but should
still range from 4-7 ft by Fri afternoon. Cond will gradually
abate later Fri night into Sat, with 25-kt gusts confined to
the ocean and ern bays late Fri night, and to the ern ocean
waters daytime Sat as seas fall to 4 ft.
After a lull Sat night, SCA cond should return to the ern ocean
waters and the ern Sound/bays by daytime Sunday and continuing
into Mon as WSW-SW flow after a warm frontal passage increases,
with gusts over 25 kt and seas 5-7 ft. There may be a brief lull
in these conditions late Sunday night into Mon morning.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Wind Advisory from 6 AM this morning to 10 PM EST this evening
for CTZ005>012.
NY...Wind Advisory from 6 AM this morning to 10 PM EST this evening
for NYZ067>075-078>081-176>179.
NJ...Wind Advisory from 6 AM this morning to 10 PM EST this evening
for NJZ002-004-006-103>108.
MARINE...Gale Warning until 1 AM EST Friday for ANZ331-335-338-340-345.
Gale Warning until 6 AM EST Friday for ANZ332-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...JC/JE/DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...JC/DR
MARINE...BG/DS
HYDROLOGY...BG/DS