361
FXUS61 KOKX 061839
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
139 PM EST Thu Feb 6 2025
.SYNOPSIS...
Low pressure impacts the area today before moving to the
northeast tonight. High pressure builds back into the area for
Friday and into the first half of the weekend. Another area of
low pressure impacts the area Saturday night into Sunday. High
pressure returns Sunday into Monday night. A series of low
pressures may pass south of Long Island Tuesday and Wednesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The precipitation is beginning to end west to east and will
completely exit the area over the next hour or so.
Winter Weather Advisories have expired, but an SPS remains for
parts of the interior for the exiting wintry mix due to
temperatures still below freezing in these areas.
Patchy fog may continue into the early evening, but increasing winds
will lead to the fog clearing.
Winds will increase from the W and NW tonight, allowing for any
fog to mix out as drier air moves in. Lows tonight will be in
the low to upper 30s.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
High pressure builds in behind the departing low on Friday. This
will bring in a drier airmass, though a tightening pressure
gradient will allow for windy conditions on Friday with gusts
upwards of 30-35 mph, locally to 40 mph possible. High
temperatures on Friday will be in the middle to upper 30s.
High pressure continues to build into the area with dry
conditions and diminishing winds Friday night. Low temperatures
will be in the teens for the inland areas with the low to middle
20s expected for the coast. The cold airmass remains in place on
Saturday as high pressure begins to slide overhead. Highs will
be in the low to middle 30s for much of the area on Saturday.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Confidence is increasing in active period with several chances for
wintry weather.
*Key Points*
*Recent model trends indicate increasing probabilities for an
accumulating/advisory level snowfall and low potential for warning
level snowfall across the interior Saturday night.
*The accumulating snow may transition to a wintry mix late Saturday
night, especially closer to the coast.
*A series of low pressures may pass off the Middle Atlantic Tuesday
into Wednesday with another chance for snow.
Fast, zonal flow aloft will continue into early next week. The
modeling has been in excellent agreement with a fast moving middle
level shortwave and strong upper jet moving towards the region
Saturday night. The differences in the guidance continue be with the
exact track of the parent low and its transfer to the coast by early
Sunday morning. The system is fast moving and will pull away from
the area Sunday morning and early Sunday afternoon.
There have a been a few notable dprog/dt trends over the last
several cycles of the models that may be beginning to shed a little
clearer picture of the evolution of the event. The parent low will
likely be moving across the Ohio Valley in the evening with its
associated warm front approaching from the southwest. The trend has
been for the parent low to track into western PA rather than up into
western NY. The low then transfers to a secondary low along and just
off the Middle Atlantic coast. As a result, the model consensus is
starting to lean towards a colder solution especially at the
beginning of the event as departing high pressure leaves behind a
cold and dry air mass Saturday evening. There may still be some
mixing/ptype changes closer to the coast as warmer air aloft tries
to get into the area late at night. Some warmer surface air may also
try to edge north across portions of the NYC metro and Long Island,
but the magnitude of this is a bit uncertain. If the secondary low
develops quicker, it may help keep the flow more N or NE and hold
back some of the warmer air. These are some of the mesoscale details
that still need to be worked out in the next 24 to 48 hours.
The current anticipated evolution will be a period of accumulating
snow beginning Saturday night 7pm to 10pm, from west to east. The
system will likely have more moisture and more organized dynamics to
work with compared to the event today (early Thursday morning).
Model soundings indicate strong lift in the Dendritic growth zone
along with thermal profiles favorable for all snow area wide the
first half of the night. Moderate snow is possible and there could
be some bands of heavier snow with some of the modeled 850-700mb
frontogenesis. Sometime around or just after midnight some warmer
air aloft may try to bring a mix of of snow and sleet along the
coast and potentially into the NYC metro. Most of the global models
show this, but the timing and magnitude differ. However, given how
quickly the modeled QPF increases before the potential transition,
advisory level snowfall is possible even down to the coast.
Locations further inland should stay snow well into the early
morning hours with any mixing potentially coming from the loss of
snow growth and weaker lift. Some colder air could wrap back into
the system as the storm pulls away early Sunday morning, but lift is
not as impressive. Any lingering precip should end shortly after day
break Sunday based on the latest trends.
NBM probabilities for a 3 inches or more (advisory level) of snow
between 00z and 12z Sunday have been steadily increasing over the
last three cycles. They were around 50 percent for Southern CT and
the Lower Hudson Valley on the 13z Feb 5th cycle and are now around
80 percent on the 01z Feb 6th cycle. These probabilities have also
increased down to the coast and went from around 20 percent to
around 50 percent on the 01z cycle. NBM probabilities have also
increased for 6 inches (warning level) going from about 15 percent
to 50-60 percent inland. The probability for a 6 inch event at the
coast notably jumped from near 0 to about 15-20 percent. Based on
collaboration with neighboring offices and WPC, our latest official
snowfall forecast ranges from 2-4 inches Long Island and NYC metro
up to 4-6 inches with isolated amounts up to 7 in higher elevations
for interior NE NJ, Lower Hudson Valley and Southern Connecticut.
Adjustments to these totals are expected given that this is still 3
days out. A further north track would lead to lower snowfall totals
whereas a further south track could lead to higher totals down to
the coast. A brief period of freezing rain is possible, but have
left out of the forecast for now given some lingering uncertainties
with the depth of the surface cold as well as the potential warm
nose. Any freezing rain if it were to happen would be well after
midnight.
Dry conditions return on Sunday into Monday with high pressure
building over the region. The baroclinic/thermal gradient looks to
reside a bit further south than this week with several areas of
shortwave energy riding along this gradient. Guidance continues to
signal a series of low pressures passing to our south Tuesday and
potentially into Wednesday. Lots of questions remain with whether or
not it will be one main wave or broken up into different periods.
However, the chance is there for another wintry event mid next week.
The current model consensus was followed which gives a snow
solution. There is still room for this to trend a bit more
suppressed, which could lower precip amounts. For this reason, have
capped PoPs off at 50 percent for now.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
Low pressure moves northeast of the region this evening. A cold
front moves across early Friday. High pressure follows
thereafter.
Precipitation, mainly rain for this afternoon, tapering off late
afternoon. Mainly IFR conditions with localized LIFR conditions
expected through much of this evening. Improvement expected
overnight and into Friday from MVFR to eventually VFR. Slight timing
differences with respect to the terminals comparing the western
terminals to more eastern terminals.
Winds initially light near or less than 5 kts, with generally
easterly direction, but variable direction at times, will overall
become more SW tonight near 10 kt. The winds become more westerly
Friday at near 15-20 kt with gusts developing near 25-30 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely to refine the timing of categorical changes and
for timing of when wind gusts begin and end.
.OUTLOOK FOR 18Z FRIDAY THROUGH MONDAY...
Friday: VFR. NW winds near 15-20 kt gusting to near 25-30 kt,
diminishing at night.
Saturday: VFR morning into afternoon. MVFR to IFR, at times
lower at night, with snow developing, eventually transitioning
to a wintry mix.
Sunday: Snow, rain/snow mix ending early. Conditions improving to
VFR. NW wind gusts near 15-20 kt.
Monday: Mainly VFR.
Tuesday: VFR morning. Potential for MVFR, IFR and lower in afternoon
with chances of snow.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions are expected this morning with a building sea
allowing for SCA conditions on the ocean by this afternoon and
evening. Increasing W and NW winds tonight and especially on
Friday behind a departing low will allow the expansion of SCAs
to the rest of the waters. Gusts will generally be 25-30kt,
though a gale force gust can`t be entirely ruled out on Friday
for the waters. Sub-SCA condition are then expected Friday night
and through at least Saturday.
SCA conditions are possible on the ocean Saturday night into Sunday
as low pressure impacts the waters. High pressure then returns with
a weak pressure gradient and conditions below SCA levels Sunday
night into Monday night.
&&
.HYDROLOGY...
There are no hydrologic concerns through the forecast period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EST Friday for ANZ331-
332-335-338-340-345.
Small Craft Advisory until 6 PM EST Friday for ANZ350.
Small Craft Advisory from 6 PM this evening to 6 PM EST Friday
for ANZ353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/MW
NEAR TERM...BR/MW
SHORT TERM...MW
LONG TERM...DS
AVIATION...JM
MARINE...DS/MW
HYDROLOGY...DS/MW