241
FXUS61 KOKX 021232
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
732 AM EST Thu Jan 2 2025
.SYNOPSIS...
Strong low pressure will move northward into the Canadian Maritimes
today and then will retrograde into SE Canada tonight into Friday. A
disturbance moves through Friday into Friday night with weak high
pressure building in thereafter briefly for Saturday. High
pressure will remain to the south and west this weekend while
strong low pressure remains over Atlantic Canada. Another low
will pass to the south through the Mid Atlantic region late
Sunday night into Monday, followed again by high pressure
remaining to the south and west and low pressure across eastern
Canada.
&&
.NEAR TERM /THROUGH TONIGHT/...
Another windy day expected today into this evening. Wind gusts
reaching up to 40 to 50 mph across the region, maximum gusts
likely late morning through early evening with daytime mixing.
The pressure gradient will be tight between strong low pressure
moving northward into the Canadian Maritimes and high pressure
well to the southwest of the region.
In addition, with mid level positive vorticity advection with a
shortwave moving in, will have just enough moisture to give
sprinkles or snow flurries to the region for some locations.
The sprinkles or flurries will vary depending on temperatures
and ensuing wet bulb cooling.
High temperatures today from MOS consensus, mainly in the lower
40s.
More mid level zonal flow and leaning towards more negative
vorticity advection tonight. Mainly dry conditions are expected.
Boundary layer remains gusty, mitigating the low temperature
range, mainly ranging from lower to upper 20s. By late evening
and into overnight, expecting wind gusts to be decreasing more
with gusts more in the 30 to 40 mph range.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
More trough development expected in the mid levels Friday
through Friday night. A strong shortwave moves south of the
region Friday night.
For Saturday, shortwave activity and positive vorticity remain
active south of the region but may move near from the northwest
Saturday night into early Sunday. Overall mid level flow across
the region remains northwesterly.
At the surface, low pressure retrogrades more within SE Canada
Friday. However, another low moves across the Appalachians
Friday and then further develops offshore well southeast of the
local area Friday night. Then, weak high pressure briefly builds
in for Saturday into Saturday night.
Across the region, weather remains quite breezy and getting
progressively colder. Not expecting advisory level winds, more
in the 25 to 30 mph range for gusts. Forecast high temperatures
for Friday are mainly in the mid 30s to near 40 and are mainly in
the low to mid 30s for Saturday.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Key Points:
* Cold with persistent NW flow through the period.
* Some light snow is possible on Monday as low pressure passes to
the south.
The big picture aloft late this weekend shows high latitude
blocking, with upper ridging across Greenland and a deep closed low
not too far from 50N/50W, also split flow across the western CONUS
with a broad upper ridge off the West Coast and a closed low moving
eastward in the southern stream through the Plains states.
Conds will be brisk/dry on Sunday with the area under a pressure
gradient between high pressure off the south/west and strong low
pressure over Atlantic Canada, then we should see at least a
glancing blow from the southern stream sys late Sunday night into
Mon. With northern stream energy remaining bottled up across Canada
this sys should remain progressive/weaker and keep moving eastward
through the Mid Atlantic region, close enough to forecast chance PoP
for light snow accumulation mainly for the NYC metro area and Long
Island for this time frame.
The ECMWF suggests only light accumulations at most, but the model
has been trending slowly northward over the last several forecast
cycles, which could open the door to a worst-case advy level
snowfall for western Long Island through NYC metro and NE NJ, which
is being shown by the ensemble 90th percentile forecast. At any
rate, the axis of heavier snow with this system should remain
well south.
Dry/cold wx expected for Tue-Wed with persistent NW flow between
high pressure off to the SW and persistent low pressure over eastern
Canada.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
VFR as low pressure continues to move NE and away from the area
overnight, and high pressure slides to the south and west
daytime Thu into Thu night.
W flow 10-15 kt with G20-25kt should increase by 14Z to 15-25
kt with G35-40 kt. Winds gradually diminish after 23Z-24Z but
remain gusty.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Occasional G40kt possible today.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday through Sunday: Mainly VFR. W winds G20-25kt.
Monday: Chance of light snow. MVFR cond likely, IFR possible at
the NYC metros/KISP.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Low water advisories issued for the low tide cycle late today
into this evening. Blended TWL guidance suggests abnormally low
water levels of 2 to 2.5 ft below MLLW along parts of NY Harbor
and the western Sound. This could cause issues for moored boats
and shallow water navigation.
Adjustments made to ocean gale warnings and some of the non-
ocean water gale warnings. They go more into tonight.
By Friday, SCA conditions expected for most waters but NY Harbor
and Western LI Sound will be more marginal for SCA as gusts
there only reach near 20 kt.
For Friday night, briefly sub-SCA for all waters. Then, SCA
conditions are forecast once again for all waters Saturday into
Saturday night.
SCA cond on all waters daytime Sunday, with NW flow gusting to
25-30 kt and ocean seas 4-7 ft, should gradually abate Sunday
evening, with quiet cond on all waters late Sunday night into
Mon as low pressure passes to the south. Minimal SCA cond likely
in the wake of this sys on the ocean, with NW flow once again
gusting to 25 kt and ocean seas approaching 5 ft farther
offshore.-- End Changed Discussion --
&&
.HYDROLOGY...
No significant hydrologic issues anticipated.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Wind Advisory until 10 PM EST this evening for CTZ005>012.
NY...Wind Advisory until 10 PM EST this evening for NYZ067>075-
078>081-176>179.
NJ...Wind Advisory until 10 PM EST this evening for NJZ002-004-006-
103>108.
MARINE...Gale Warning until midnight EST tonight for ANZ331-335-340-345.
Gale Warning until 4 AM EST Friday for ANZ332-350-353.
Low Water Advisory from 7 PM to 9 PM EST this evening for
ANZ335.
Gale Warning until 10 PM EST this evening for ANZ338.
Low Water Advisory from 4 PM this afternoon to 6 PM EST this
evening for ANZ338.
Gale Warning until 1 AM EST Friday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...BG
AVIATION...BG
MARINE...BG/JM
HYDROLOGY...BG/JM
TIDES/COASTAL FLOODING...