358
FXUS61 KOKX 031737
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1237 PM EST Fri Jan 3 2025
.SYNOPSIS...
Low pressure continue to retrograde into SE Canada today.
Meanwhile another low develops well south of the region today
and moves well offshore tonight. High pressure will remain south
and west of the region with low pressure north of the region
going into this weekend. Low pressure passes through the Mid
Atlantic on Monday and offshore Monday night. Behind it, strong
Canadian high pressure builds in from the west through mid next
week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Longwave troughing continues anchored by a deep closed low over
Quebec thru tonight, with northern stream shortwave pivoting
from the eastern Great Lakes through the region tonight. At the
surface, a cold front crosses east of the region by this
evening, with weak surface wave developing well south and east
of the region.
Increasing cloud cover through the aft/eve with potential for a
few flurries/isolated snow showers, with shortwave trough/cold
frontal passage this evening. Higher probability for steadier
light snow remains across Central NJ and points south, but
slight chance for a dusting across southern portions of NYC/NE
NJ. Otherwise localized dusting possible with any snow shower
activity. Any accum would be on mainly on grassy or elevated
surfaces, and primarily across interior and higher elevations.
Temperatures getting colder today compared to the previous day
with cold air advection. Daytime mixing will achieve high
temperatures mainly in the mid to upper 30s. Some 40 degree high
temperatures are forecast along the coast.
Gusty winds remain but will be more in the 25 to 35 mph range.
This will make for temperatures to actually feel like freezing
or slightly below freezing for maximum wind chills.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
In the mid levels, the region remains in between cutoff low in
SE Canada and ridging well to the south and west. WNW mid level
flow increases over the weekend with a tightening height
gradient.
The low pressure develops well southeast and offshore. Again,
northern fringe of precipitation get close to Long Island but
only chances of snow are south of Long Island within the
forecast marine zones with higher chances farther to the south.
Otherwise, winds slightly subside but still stay up enough to
keep a mixed boundary layer. Gusts do not completely go away
tonight with gusts still frequent along coast. Lows forecast
are in the 20s but minimum wind chills will be near the 10 to 15
degree range.
For the weekend, the core of high pressure remains well to the
south and west, keeping a tight enough pressure gradient to
maintain gusty winds. Expecting mainly dry conditions for much
of the weekend. NW winds continue and advect in even colder air.
Highs forecast on Saturday and Sunday are only in the low to
mid 30s. Wind chills both days will be at most mainly within the
20s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Key Points:
* Light snowfall possible Monday as low pressure passes to the south.
* Temperatures remain below normal through much of next week
with persistent NW flow.
An active start to the period as low pressure tracks from the
Mississippi River Valley this weekend through the Mid Atlantic on
Monday, introducing chances for precipitation locally. Timing of any
precip looks to be during the day on Monday, tapering Monday night.
Given the cold air mass in place, ptype would likely be all snow.
The question becomes how much moisture will make it this far north.
Some guidance, like the 00Z GEFS, offers a wetter, more amplified
solution that brings the FGEN axis into the region. On the other
hand, the EPS and GEPS members largely keep the bulk of the
accumulating snowfall just to the south with a flatter wave. These
differences will need to be resolved and are key in determining
ultimately where the snowfall occurs. NBM probabilities of at least
1 inch of snow have been creeping up with each run, now about 50%
for NYC and surrounding areas. Lessening chances, though not zero,
for accumulating snow going north into the LoHud Valley and southern
CT, but trends will need to be monitored closely.
All to say, a light snowfall is possible for at least portions of
the area on Monday. If the more amplified northern solution proves
valid, winter headlines *could* eventually be needed for the
southern half of the CWA.
Conditions dry out Tuesday as the low moves offshore, and a nearly
blocked upper flow persists through at least mid next week with
sprawling low pressure centered over far eastern Canada. Behind the
system, Canadian high pressure drops south into the Plains and
builds in, reinforcing the cold air mass and maintaining a tight
pressure gradient that will keep winds blustery. Temperatures look
to run up to 10 degrees below normal through the period, with
afternoon highs near freezing, and morning lows in the teens and
20s. Wind chills likely in the single digits at times given the flow.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A quick moving weak low passes to the south and offshore late
this afternoon, meanwhile a sprawling area of low pressure
remains centered to the north of the region as high pressure
builds to the west.
VFR.
W flow persists this afternoon, with gusts 20-25kt. Gusts may be
more occasional before ending late in the day. Winds back toward
NW tonight with gusts redeveloping to around 25kt. Winds and
gusts increase Saturday morning, and toward 18Z gusts may be
35-39kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may be more occasional through this afternoon, before
ending. Gusts redevelop late tonight 05Z/06Z and may begin an
hour or two later than forecast.
Occasional gusts up to 40kt possible Saturday afternoon.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday afternoon: VFR. WNW winds 18-25kt, gusts 25-35kt,
occasional gusts up to 40kt, especially along the coast.
Sunday: VFR. W gusts 20-25kt. MVFR with a chance of light snow
at the NYC metro terminals toward Monday morning.
Monday: IFR at the NYC metro terminals and KISP with snow. MVFR,
IFR possible, with light snow at the other terminals.
Tuesday: VFR. WNW winds 15-20kt, gusts 25-30kt.
Wednesday: VFR. W gusts 20-25kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA conditions are in place for all the forecast waters. SCA
for non-ocean zones goes until 4pm this afternoon with ocean
zones having SCA until 7am Sunday. SCA on the ocean may very
well need to get extended through the day Sunday. Non-ocean
waters will have a lull in wind gusts tonight but for those
zones, SCA conditions will probably return overnight tonight and
into the weekend.
SCA conditions may briefly abate on the ocean Sunday night and
Monday, before returning Monday night or early Tuesday as NW flow
increases and seas once again build over 5 ft. SCA conditions then
appear likely on all waters Tuesday through midweek, with persistent
wind gusts above 25 kt. There is also potential for gusts across the
ocean waters to be near gale force, especially east of Fire Island
Inlet, late Tuesday into Tuesday night.
&&
.HYDROLOGY...
No significant hydrologic issues anticipated through the middle
of next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ331-
332-335-338-340-345.
Small Craft Advisory until 6 AM EST Sunday for ANZ350-353-355.
&&
$$
SYNOPSIS...JM/DR
NEAR TERM...JM/NV
SHORT TERM...JM
LONG TERM...DR
AVIATION...MET
MARINE...JM/DR
HYDROLOGY...JM/DR