000
FXUS61 KOKX 141814
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
114 PM EST Sun Jan 14 2024
.SYNOPSIS...
Deep low pressure remaining in southeastern Canada today will
bring an Arctic cold front through the region today. High
pressure builds to the southwest tonight and Monday. Low
pressure will approach Monday night and pass to the south and
east on Tuesday. High pressure will then build to the south on
Wednesday and slide off the coast on Thursday. Another low will
pass to the south on Friday and then move east on Sunday as
strong high pressure builds into the Plains and Midwest.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
After surveying various sites with NAM and GFS BUFKIT profiles,
confidence increasing on wind gusts of 45 to 50 mph to be
reached especially for the latter half of this afternoon. There
is a wind advisory in effect until 6PM for the entire forecast
region.
Snow shower and snow squall activity entering western portions
of the region. However, conditions more favorable with
temperatures closer to freezing for far northern interior areas
so there is where conditions will be more primed for snow to
stick to untreated surfaces with possibility for flash freeze.
This will be for Orange NY, Putnam NY as well as interior parts
of Southern CT. Little to no snow accumulations expected to the
south with no measurable snow expected in and around NYC and
Long Island.
HRRR and other mesoscale models depict the snow shower activity
to traverse the region mainly before 4PM. Mainly dry conditions
with an eventual decrease in clouds is expected thereafter.
A deep upper low will continue to move through southeastern
Canada today as deep cyclonic flow remains across the
northeast. An amplified shortwave with an embedded short vort
max will rotate through the upper trough into this afternoon.
An accompanying Arctic cold front will sweep through the region.
While the atmospheric column will be rather dry the dynamics
will be enough to produce a chance of precipitation along and
just behind the Arctic boundary with the better lift, low level
lapse rates, and instability across the northern tier. With the
cold air moving into the region most areas will see a chance of
snow showers, while near the coast temperatures will be more
marginal just ahead of the front for rain showers at the onset
becoming snow showers as the front passes. Steepening low level
lapse rates, up to 700mb, will be mixing down low level winds of
60-70kt as the Arctic front moves through. While synoptic winds
will be strong and gusty as the front moves through winds and
gusts will increase. There is medium to high confidence
that a brief period of gusts reach up to 40 to 45 kt at the
surface especially across the northern tier. Low possibility of
a brief 50 kt gust.
With the potential for a period of snow squalls will handle the
quickly reduced visibilities and stronger winds with short term
special weather statements, or possibly snow squall warnings if
warranted. The CAMs have been indicating the potential for snow
squalls. Also with the steepening lapse rates and some
instability, along with weak elevated CAPE, a rumble of thunder
is possible with the heavier snow showers. A quick coating of a
few tenths on an inch, maybe up to 1/2 inch, of snow are
possible especially inland. The strongest cold air advection
behind the front will likely be after any precipitation ends,
21Z to 06Z, as temperatures fall to as much as 10 degrees below
seasonal normals tonight.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
The cold airmass remains in place tonight and Monday as the deep
cyclonic flow comes to an end this evening as high pressure
begins to build in to the southwest and the southeastern Canada
low gradually tracks farther to the northwest. Temperatures
will remain as much as 10 degrees below normal.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Initial focus will be on snow chances from late Mon night into
Tue as a broad upper trough approaches from the west, and
associated sfc low pressure developing off the SE coast passes
just SE of the 40N/70W benchmark Tue evening. There could be
some initial light snow late Mon night as a mid level baroclinic
zone and associated frontogenetic forcing lift NE into the
area, but the main time frame for any light snow will be daytime
Tue as the sfc low organizes and passes to the SE, and as right
entrance region forcing of a developing upper jet streak
associated with the trough to the west passes across and
interacts with the mid level baroclinicity. This setup favors a
light mainly sub-advisory snowfall daytime Tue, with most places
receiving 1-2 inches, and some locales seeing closer to 3
inches. PWPF guidance still shows some spread, with anywhere
from less than an inch (discounting this due to presence of the
upper jet), and higher end amts of 3-4 inches if the offshore
low and/or upper jet/baroclinic zone interaction are stronger.
For Friday, guidance is in closer agreement on potential for
another snowfall event as a digging nrn stream trough closes
off over the Great Lakes and ern Canada, and a sfc low develops
near then srn Mid Atlantic and heads out to sea. Still carrying
high chance PoP for this event, with details still uncertain
this far out in time.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
An Arctic cold front will move across this afternoon. Low
pressure moves into the Canadian Maritimes tonight into early
Monday. High pressure builds southwest of the region.
WSW winds ahead of the front will be near 15-25 kt with gusts
near 25-35 kt. After the frontal passage, winds become more
W-WNW and increase to near 25 kt with gusts near 40 kt. Gusts
up to near 45 kt will be possible late this afternoon and early
this evening. Winds will then slowly weaken tonight.
Brief IFR to LIFR in snow showers or potentially snow squalls
this afternoon. NYC terminals, KHPN and KSWF snow shower
activity ends by around 19-20Z. To the east, the snow shower
activity ends by around 20-21Z.
Higher chance for light snow accumulation less than 1 inch for
KSWF, KHPN, and CT terminals.
Expect mainly VFR conditions after 20-21Z and through the
remainder of the TAF period.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of return to VFR could be off by 1-2 hours.
Occasional 35-40 kt gust possible early this evening, mainly
before 02Z.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon: VFR.
Monday night: MVFR or lower possible, with chance of light snow.
Tuesday: IFR with light snow likely, tapering off in the
evening.
Wednesday: VFR. W wind gusts near 20-25 kt.
Thursday: VFR. W wind gusts near 20 kt.
Friday...IFR possible with snow likely. NE-N wind gusts near 20
kt in the afternoon.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
The gale warning remains in effect through much of this evening
for all waters. A few gusts on the ocean waters may briefly
reach storm force behind an Arctic cold front passing through
the waters through the afternoon. Once gales end this evening a
few hours of SCA gusts will be possible across the forecast
waters, however, ocean seas remain at SCA levels tonight, and
gradually fall below during Monday.
SCA cond likely on most waters Tue night-Wed after low pressure
passes to the east. Cannot rule out a brief pd of minimal NW
gale force gusts on the ocean waters Wed evening after passage
of an upper level disturbance. Residual SCA cond should linger
on the ocean into daytime Thu as the pressure gradient remains
tight, then quiet cond expected by Thu night ahead of the next
low pressure system.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic impacts expected through Saturday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Wind Advisory until 6 PM EST this evening for CTZ005>012.
NY...Wind Advisory until 6 PM EST this evening for NYZ067>075-
078>081-176>179.
NJ...Wind Advisory until 6 PM EST this evening for NJZ002-004-006-
103>108.
MARINE...Gale Warning until 10 PM EST this evening for ANZ331-332-335-
338-340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/MET
NEAR TERM...JM/BR/MET
SHORT TERM...MET
LONG TERM...BG
AVIATION...JM
MARINE...BG/JM/MET
HYDROLOGY...BG/MET