692
FXUS61 KOKX 102347
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
647 PM EST Fri Jan 10 2025
.SYNOPSIS...
An upper level disturbance pivots through Saturday while low
pressure passes well offshore. High pressure builds in and settles
Sunday before pushing offshore Monday in response to an approaching
cold front. The cold front passes Monday night. High pressure
builds in again for the middle of next week. Another low from
Canada may approach Thursday into Friday.
&&
.NEAR TERM /THROUGH SATURDAY/...
For this evening update, only minor adjustments were made to
account for current observations and trends. The forecast
remains on track.
High clouds continue to spill into our area and and thin out leading
to mostly clear conditions, especially the eastern half of the
area. Cloud cover will increase later this evening as the upper
level ridge axis passes to the east. The pressure gradient at
the surface continues to weaken and in turn winds and wind gusts
are gradually lowering. Depending on timing of thicker cloud
cover, some locations may be able to cool quickly right after
sunset this evening, mainly eastern locations. This could cause
current low temperature forecast to be too warm by a degree or
two in the usual cold spots.
There has not been much change in guidance with the upcoming light
snowfall event. Currently, a low pressure system is located over the
southeast US. This low will track towards our area and pass well
offshore to our south and deepen rapidly once it interacts with
a northern stream upper level trough that will pass over our
area as it becomes negatively tilted. Good agreement in track
continues with the latest 12z deterministic models. There has
just been a very subtle southward shift with the surface low
(expected to pass about 300 miles offshore) and how deep the
upper level trough digs.
This did not lead to a whole lot of change in the PoP and QPF
forecast. Did bump up Pops to likely as we are 12-18 hours out and
confidence is increasing in at least a 3 hour period of some
measurable precipitation. QPF ranges from 0.01 to 0.05 and
combined with SLRs around 14:1 to 16:1 the forecast snow totals
are around 0.3 to 0.7.
Forecast soundings do show quite a bit of dry air to overcome around
800mb. This was the reasoning for starting PoPs a few hours after
what the CAMs model reflectivity fields show. Light snow is possible
through late morning, with a dry afternoon thereafter.
&&
.SHORT TERM /SATURDAY NIGHT/...
The upper level trough axis will be just east of the area at the
start of Saturday night. High pressure starts building in at the
surface and the pressure gradient across the area tightens. This
will lead to a brief period of some gusty conditions Saturday
night. With gusty winds, effective radiational cooling is not
expected and stuck close to the NBM for lows.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
High pressure builds into the region at the surface as an upper-
level ridge centers itself overhead. Both of these features push
east offshore on Monday in response to a sfc and upper-low
approaching from the Great Lakes on Monday.
NW winds continue to weaken on Sunday turning W Sunday night as they
go light or calm then turning SW on Monday in response to high
pressure moving offshore. Dry, sunny weather is expected on Sunday
before increasing clouds late Sunday night into Monday. Temperatures
will be near seasonal values Sunday into Monday. Highs on Sunday and
Monday will be in the upper-30s to lower-40s. Lows Sunday night will
drop into the low to upper-20s.
A dry front pushes through Monday night as weak low pressure passes
to the north. A trough digs an amplifies over the region Tuesday
into Tuesday night, moving offshore on Wednesday. The region will
then remain sandwiched in-between high pressure to the west and low
pressure to the east on Wednesday and Thursday.
Blustery weather is expected to develop on Tuesday and remain
through at least Thursday due to a a tight pressure gradient. Winds
will not be as impactful as our recent stretch of gusty winds, but
still expected NW winds to gust 25-30 mph, at times during this
period.
Strong cold air advection takes place Monday night into Tuesday
following the frontal passage aided by a deepening trough and lower
heights. Highs will be around freezing (32F) to the upper-20s
Tuesday through Thursday. Lows each night will likewise be colder in
the low-20s to mid-teens. Given the gusty NW flow, wind chills will
be in the 20s to teens each afternoon, dropping to the single digits
each night.
While most of the long-term period is expected to be dry, there are
some hints in global guidance that a surface trough may extend
across the area Tuesday night into early Wednesday. Given dry air
entrenched in the area, its unlikely precip will develop along this
trough, but at least partly cloudy skies look likely. Some isolated
flurries can not be ruled out. Flurries have not added to the
official forecast, for now, given low confidence in flurries
actually occurring.
Thursday into Friday, most global models agrees on a weak low in
Canada nearing from Hudson Bay, but they vary on its location. Some
models keep high pressure in charge, while others bring the low
closer to the region, with light snow possible in this scenario.
Both scenarios would keep us under a somewhat tightened pressure
gradient with continued breezy conditions. Though overall, winds may
end up being a little weaker than what we see Tue through early
Thu.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Weakening high pressure builds into the area through this evening
and then offshore by daybreak. Developing low pressure will pass
well south and east of the area late tonight into Saturday. A weak
surface trough extending north of the low will pass through the
area in the morning.
VFR through late tonight. A period of light snow is possible
late tonight into Saturday morning, which may bring categories
down to MVFR. Accumulation is expected to be limited to a light
coating (less than 0.5").
Gusty NW flow will gradually back into this evening as speeds
fall below 10 kt, eventually becoming light and variable. Winds
will then become NW late morning into the afternoon with gusts
up to 20 kt toward evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of light snow and MVFR conditions may vary by 1-2 hours.
OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday Afternoon: Becoming VFR all terminals. NW gusts 20 kt
possible in the afternoon into the night.
Sunday-Monday: VFR.
Tuesday-Wednesday: VFR. NW wind gusts 20-30 kt possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
With the pressure gradient weakening over the area, winds and waves
have lowered and fallen below SCA criteria for the first time in
several days. Quiet conditions continue tonight through much of
Saturday before northwest winds pick back up again Saturday night.
As of right now, confidence is only high enough to issue a SCA
across the ocean waters. This may need to be expanded to other
waters by subsequent shifts. Gusts up to 25 kt and seas 3-4 ft
are expected across the ocean Saturday night.
SCA conditions are not expected Sun-Mon. Midweek next week, winds
may build to SCA levels on most waters.
&&
.HYDROLOGY...
There are no hydrologic concerns through next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM Saturday to 6 AM EST Sunday for
ANZ350-353-355.
&&
$$
SYNOPSIS...BR/JT
NEAR TERM...BR/JT
SHORT TERM...JT
LONG TERM...BR
AVIATION...MW
MARINE...BR/JT
HYDROLOGY...BR/JT