869
FXUS61 KOKX 102240
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
540 PM EST Mon Feb 10 2025
.SYNOPSIS...
High pressure continues to build in tonight and passes offshore on
Tuesday. Low pressure will pass south of the area Tuesday night.
Another low pressure system moves through during Wednesday night
into Thursday, followed by high pressure Friday into Saturday
morning. A third low then impacts the weather Saturday afternoon
through Sunday with high pressure building back in on Monday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
The forecast is mainly on track. Minor updates made to hourly
temperatures and dewpoints for the evening hours.
Zonal flow continues aloft as high pressure builds over the area
tonight. Even though winds weaken, mid and high level clouds moving
in will likely dampen the effect of radiational cooling. If winds
weaken quick enough early on, this may be the type of night
where temperatures drop quick at first, and then become stable
or slightly rise with clouds moving in. To account for the
uncertainty, blended CONSMOS and some colder guidance with the
NBM.-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
The flow aloft remains mostly zonal on Tuesday as high pressure
shifts offshore. Aforementioned cloud cover will lower and become
more widespread/thick as the column slowly saturates from the top
down.
Tuesday night, a wave of low pressure will pass well south of
Long Island, but bring some light snow accumulation the the
area. Our area is on the northern edge of the expected
precipitation shield, so southern locations are expected to
receive more snowfall. Latest forecast has trended in up in QPF
and snow amount for a few reasons. An upper level jet streak to
our north has slowly been trending farther north, which places
us under the right entrance region. Some guidance has also been
trending stronger in addition to the northward shift. Given the
support from the upper jet, the thinking is that QPF across much
of the guidance could be underdone. Did not make a major
change, but have up to 0.20 inches of QPF across the southern
half of the area. HREF QPF amounts look way underdone as the
CAMs are likely struggling with the jet. The NAM is one of the
highest with 0.30 inches, which is not completely out of the
question, but before trending closer to those totals would like
to see a little more support from other guidance. It is worth
noting that the 18z NAM brings an enhanced area of 700mb
frontogenesis closer to our area than previous runs and other
guidance. This trend will need to be monitored because this
would support higher QPF as well. Also went with higher SLRs
than the previous forecast (around 13:1 average) which is
leading to 2 to 2.5 inches across NYC, Long Island and portions
of northeast NJ. Isolated 3 inch amounts are possible along the
immediate south coast. Farther north totals will be closer to .5
inches to 1 inch and northern interior CT and Lower Hudson
Valley likely see less than .5 inches.
Given the current totals, no headlines were issued. If QPF continues
to trend up it is possible that a Winter Weather Advisory would be
needed for Long Island, NYC and portions of northeast NJ.
As for timing, this will likely all be in the overnight period, with
the highest chances being between 10pm and 5am. Confidence is high
in this falling as all snow, with no other ptypes mixing in.
We dry out the rest of Wednesday, with just lingering snow chances
in the morning. We do not get much of a break as PoP chances
increase late Wednesday afternoon ahead of the next system.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Primary low pressure center shifts from the Ohio Valley into the
eastern Great Lakes Region Wednesday night before passing well to
our north during Thursday. Meanwhile, a weaker secondary low center
shifts just south of Long Island during Thursday morning. This will
bring snow to the forecast area Wednesday evening, then as a warm
nose aloft pushes in, the snow changes to a wintry mix before an
eventual changeover to rain late Wednesday night through Thursday
morning. Rain then tapers off late morning into the afternoon.
Thermal profiles aloft among the various models differ with GFS
continuing to be a cold outlier, particularly from approx 09-15z
Thurs. Didn`t want to completely discount the GFS, so did take it
into some consideration regarding precip types. Right now it appears
that a snow/sleet accumulation of 1-2 inches will occur for LI, NYC
and right along the CT coast with 2-3 inches elsewhere. Light ice
accumulations of up to a few hundredths of an inch expected outside
of LI, NYC and the urban corridor of NE NJ. Advisories could
eventually be needed for these areas that are expected to have an
ice accumulation, with combined snow and ice presenting
slippery/hazardous conditions.
Dry and somewhat breezy Thursday night into Friday morning as high
pressure builds in behind the departing storm. Its ridge axis shifts
through here during Friday evening with light winds. Highs on Friday
below normal in the lower and middle 30s.
A stronger and wetter system is then anticipated to approach from
the SW on Saturday before passing through or nearby to our NW during
Sunday. Precip becomes likely Saturday afternoon into evening and
probably ends by Sunday evening. Kept precip types simplified for
the time being with rain, snow or a mix of the two. Too early to
have much confidence in potential snow accumulations, but with that
said, rain appears to be the dominant precip type with this
storm.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
High pressure continues to build over the terminals into tonight.
The high pressure weakens on Tuesday as low pressure develops across
the southeast.
VFR through the TAF period with high pressure in control through
Tuesday.
NW winds will begin weakening this evening, diminishing to around 5-
7 kt overnight. Outlying terminals will likely become light and
variable. Winds Tuesday morning become SW and will be under 10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Occasional gusts around 20 kt will end by 22z.
.OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday Afternoon-Night: VFR afternoon, becoming IFR/LIFR at night
in light snow especially across NYC metro and Long Island terminals.
Wednesday: Lingering light snow ends early. VFR possible into
afternoon. NE gusts 15-20 kt in the afternoon.
Wednesday Night-Thursday: Snow/wintry mix developing Wednesday
evening with IFR/LIFR. Wintry mix becomes plain rain at the coast
late, gradually becoming plain rain inland Thursday morning. NE
gusts 15-20 kt Wednesday night.
Friday: VFR. NW wind gusts 15-20 kt during the day.
Saturday: VFR early. MVFR or lower possible with rain/snow mix near
coast and snow inland late.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
Sub-Small Craft Advisory conditions are expected on all waters
through Tuesday night. E/NE winds increase on Wednesday and
marginal Small Craft Advisory conditions are possible on the
ocean waters with 25 kt gusts and 5 ft seas.
SCA conds expected on all waters Wednesday night, followed by a
brief lull Thursday morning as a weak low center passes nearby.
Offshore winds will increase in the afternoon, but advisory
conditions might be limited to only the ocean waters. The
pressure gradient then perhaps tightens enough Thursday night
into Friday morning for all waters to have advisory-level gusts
during the period. Winds and seas subside throughout the day
Friday with sub- advisory conditions even on the ocean waters by
early evening. Southerly winds increase for Saturday, but
conditions look to be short of advisory thresholds. A better
chance of SCA conds arrives Saturday night.-- End Changed Discussion --
&&
.HYDROLOGY...
At this time there are no hydrologic concerns through early next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...JC
AVIATION...DS
MARINE...JC/JT
HYDROLOGY...JC/JT