779
FXUS61 KOKX 120055
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
755 PM EST Wed Dec 11 2024
.SYNOPSIS...
A cold front swings east of the area tonight. High pressure will
gradually build Thursday and settle over the region Friday into
Saturday. High pressure slips offshore early Sunday with a weak area
of low pressure potentially passing through early next week before
another frontal system potentially impacts the area Tuesday into
Wednesday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
*A Flood Watch remains in effect for southern CT through 1 am
tonight.
*A High Wind Warning remains in effect for eastern Long Island
and far SE CT until 11 pm, and until 10 pm for the remainder of
Long Island and No. New London, Middlesex, and Southern New
Haven. A Wind Advisory remains in effect for the NYC and NE NJ
metro, Southern Westchester, and southwestern CT through 10 pm.
*Peak southerly winds 25 to 35 mph with gusts of 60 mph for LI
and southeastern CT. Peak southerly winds 20 to 30 mph with
gusts 45 to 50 mph in the Wind Advisory area. Trees and power
lines could blow down with potential power outages.
Surface cold front is making its way through the region early
this evening, now thru NJ, NYC, and much of the LoHud Valley as
of 1Z. Wind shift and a temperature drop follows the fropa, and
the rain has turned to snow off to the west in portions of NE PA
and Upstate NY as colder air works in. Rain should gradually
taper west to east behind the front into tonight, and additional
amounts look largely under an inch, which should preclude more
significant flooding. Not out of the question some of the colder
elevated locales in the LoHud Valley see some snow showers as
it tapers but no accum is expected. Decided to maintain wind
headlines thru previously scheduled times given potential for
post frontal gusts with the deeper mixing, but with the LLJ now
east of the local region, the threat for the strongest winds
has ended. Previous discussion follows.
Positive vorticity advection ceases towards 0-3Z from west to east
with strong negative vorticity advection along with strong cold air
advection immediately in the wake of the cold front for late this
evening and into the overnight. This will shut off precipitation
quickly, along with the strongest wind gusts. The strongest / peak
gusts likely get off the east end of LI and far eastern portions of
New London County, CT around 3z or so. There will still be gusty
conditions, especially from 3 to 7z in strong cold air advection.
However, the strongest gusts will be over with. For the overnight
gusts on a W wind should be more on the order of 25 to 35 mph. Gusts
may weaken further during the per-dawn hours as the magnitude of
cold air advection lessens. Much colder air pours in from the west
during the overnight into the morning. Wake up wind chills are
likely to get into the lower and middle 20s across a good portion of
the area. Actual air temperatures are expected to settle close to
freezing along the coast, and a couple of degrees below further
inland. There may be a few slippery spots approaching daybreak, but
with the wind expecting much of the moisture along the ground to
evaporate. There will be still be some standing water / ponding in a
few spots which could freeze, especially further inland but all in
all not expecting widespread impacts from the cold air surge into
the morning commute.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
The last spokes of energy from the upper level trough axis pivots
through and moves N of the area Thursday. This results in some
leftover CAA, especially further north across the area. Look for a
windy day with a few gusts potentially getting to about 35 mph,
especially across northern portions of the area on Thursday.
Forecast soundings look dry with moisture trapped some at around 5
kft, thus there may be some stratcu during the late morning and
afternoon. The winds start to subside later Thursday night with
light winds during the day Friday as high pressure quickly settles
over the area. For wake up wind chills Friday morning even though the
winds decrease some, expect widespread teens to around 20. With
synoptic scale subsidence in place expect mainly clear skies for
Thursday night through Friday as dry conditions prevail for the late
week period. With the return of a cP airmass temperatures will
average near 5 degrees below average Thursday, 5 to 8 degrees below
Thursday night (but feeling colder with the wind), and closer to 10
degrees below Friday.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
The long term period will start off with a cold night Friday night.
A 1047 mb surface high builds in and will be centered just to
the north by Saturday morning. MOS guidance may be just a bit
aggressive with lows at this point given there is time for the
pressure gradient trend to change. For now, blended MOS in with
the NBM. This gives lows Friday night in the low teens across
the interior and LI Pine Barrens and 20s elsewhere. The high
remains in control on Saturday and with the cold airmass and a
N/NE flow, highs will likely only reach the 30s.
A return flow sets up Saturday night as the high shifts offshore.
Much of Sunday looks to be dry, but cloudy skies are expected as
moisture increases in the low levels from the return flow and as mid
and upper level clouds approach from the west.
Model spread increases as we head into Sunday night and through the
middle of next week. It looks like a pair of systems could bring
unsettled weather to the area. Given the uncertainty, stayed
relatively close to NBM PoPs. Any precipitation would likely fall as
plain rain, with the exception of portions of the interior where a
brief wintry mix at the start Sunday evening is possible.-- End Changed Discussion --
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
Improving conditions for the start of the forecast period as the
cold front will be moving through the area. It will be moving
through the city terminals at 00Z and progress eastward over the
next couple of hours. Conditions across NW NJ are already MVFR
to VFR, so expect to see these conditions by 03Z to 06Z across
the city terminals. Thereafter, VFR conditions expected through
the rest of the TAF period.
SW winds quickly shift to the W after 00Z. There could be a gust
or two to 40 kt as the front moves through, but for the most
part, the strongest winds have ended, though it will still be
windy, with gusts 25-30 kts. W to WSW winds remain strong
tomorrow W 15-20 G20-30 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Amendments likely for changing flight categories, especially
with the front moving through the area through 01Z. Isolated
gusts to 40 still possible with the front, but for the most part
gusts should remain below 40 kt.
OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
Thursday Night: VFR. W winds 15-20G30kt.
Friday and Saturday: VFR.
Sunday: MVFR or lower cond possible with light rain and low
clouds, especially late.
Monday: MVFR possible in showers.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Low pressure and its associated cold front impacting the waters
during the evening hours will sweep east of the waters during the
overnight and pre-dawn hours. Storm force wind conditions should
continue to about midnight or thereabouts for the eastern ocean,
otherwise gale conditions continue for the majority of the ocean
through the day Thursday. Although, the western ocean may experience
more small craft conditions vs gales during Thursday afternoon. The
non-ocean nearshore waters will experience gales force conditions
through the first half of tonight, followed by small craft
conditions through the day Thursday. Small craft conditions may
linger into a portion of Thursday night, before sub small conditions
return late at night and into Friday morning. Eastern ocean seas may
linger around 5 ft into a portion of Friday morning.
Sub-SCA conditions are expected on the waters Friday night through
Sunday. Later Sunday night into Monday small craft seas around 5 ft
on the ocean become increasingly likely.
&&
.HYDROLOGY...
Mainly minor urban and nuisance flooding through this evening.
An isolated instance of moderate flooding remains possible in
mainly urban locations and cannot be completely ruled out.
There are no hydrologic concerns for late this week through the
middle of next week.
&&
.TIDES/COASTAL FLOODING...
Water levels for most locations should once again remain below minor
flooding benchmarks even though peak surge occurs for some locations
early this evening. The relatively higher probabilities of minor
coastal impacts are related to the combination of elevated water and
splashover from wave action for places like the eastern Great South
Bay as strong southerly flow switches to southwest, which may
prevent water from escaping the bay quickly.
The combination of 10-15 ft breakers during the evening high tide
will cause widespread beach flooding and erosion. Scattered area of
dune base erosion, and localized washovers possible for LI beaches
where dunes protection is compromised.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until 10 PM EST this evening for CTZ005-006-009.
Flood Watch until 1 AM EST Thursday for CTZ005>012.
High Wind Warning until 10 PM EST this evening for CTZ007-008-
010-011.
High Wind Warning until 11 PM EST this evening for CTZ012.
NY...Wind Advisory until 10 PM EST this evening for NYZ071>075-176-
178.
High Wind Warning until 10 PM EST this evening for NYZ078-080-
177-179.
High Wind Warning until 11 PM EST this evening for NYZ079-081.
NJ...Wind Advisory until 10 PM EST this evening for NJZ006-104-106-
108.
MARINE...Storm Warning until 11 PM EST this evening for ANZ331-332-335-
340-345-350-353-355.
Gale Warning until 6 AM EST Thursday for ANZ338.
&&
$$
SYNOPSIS...JE/JT
NEAR TERM...JE/DR
SHORT TERM...JE
LONG TERM...JT
AVIATION...JP
MARINE...JE/JT
HYDROLOGY...JE/JT
TIDES/COASTAL FLOODING...