000
FXUS61 KOKX 260102
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
802 PM EST Thu Jan 25 2024
.SYNOPSIS...
A cold front will become stationary to the south tonight as a
wave of low pressure moves along it. This low will pass south of
Long Island late tonight into Friday morning, then pass to the
east Friday afternoon. High pressure will build in briefly for
Saturday. A broad area of low pressure over the Ohio and
Tennessee Valleys will approach from the southwest Saturday
night. A secondary low then takes shape off the Mid Atlantic
coast early Sunday morning, deepening and tracking south and
east of the area through Monday. Weak high pressure briefly
follows for Tuesday before a fast moving clipper system tracks
across the area late Tuesday night into Wednesday. Another area
of high pressure builds in for Thursday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
Record highs were tied at Newark and LaGuardia today, and
broken at Islip and JFK. Some cooler air will settle south
through the night as a front has passed to the south of the
area with a light N-NE flow. The front will stall to the south
as a wave of low pressure moves along it overnight. This will
bring another round of moderate rain mainly after midnight.
Some patchy fog is also likely tonight especially from the NYC
metro area north/west, where lighter winds will prevail than out
east. Elsewhere, east winds should increase enough to keep the
airmass mixed enough to limit the extent of any fog.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Rain will still be likely early Fri morning across S CT and ern
Long Island as the wave of low pressure passes S of Long
Island. Most areas should be dry by afternoon, but mostly cloudy
skies should continue as low level moisture lingers. High temps
will be in the 40s throughout.
With light winds and residual low level moisture Fri night,
areas of fog look likely, and latest GFS MOS guidance indicates
the fog could become locally dense in spots. Lows Fri might will
also be a little colder in the wake of the passing low, bear 40
in NYC but in the 30s elsewhere, possible near or just below
freezing across the interior and in the Long Island Pine
Barrens.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
* Low pressure will impact the area late Saturday night into
Monday. Rain looks to be the predominant precipitation type
at this time, but could end as snow or a rain/snow mix Sunday
night into Monday. Early assessment for potential snow
accumulation looks to be in the advisory level for inland
areas with little or no accumulation at the coast. This will
continue to be refined through the weekend.
* Turning colder Sunday into early next week. Forecast highs
only in the 30s for Monday and Tuesday. There is the potential
for a colder shot of air for the middle of next week, but
there is a large spread in the guidance.
Overall, the guidance is in better agreement with a storm
system that will impact the area late Saturday night into
Monday. There has also been a slight warming trend in the
vertical temperature profiles. That being the case, all
locations will start off rain overnight Saturday with a
potential for a changeover to snow inland Sunday night and
perhaps a snow/rain mix at the coast. Higher elevations inland
could still see this happen a bit sooner. Liquid equivalent
amounts for this event are generally around or just under an
inch. Early assessment for snowfall potential is advisory level
inland and little or no accumulation at the coast. That being
said, subtle changes in storm track and magnitude will impact
this potential. The limiting factor for a big snowfall event is
marginally cold airmass and lack of a strong high to the north.
The latter of which is coming in behind the system. So
dynamical cooling will be the main mechanism to cool the column
enough for potential snow. Gusty NE winds will also accompany
the system with gust 25 to 35 mph, highest along the immediate
coast. Conditions dry out from west to east Monday, with much
of the area dry by the afternoon.
High pressure builds in for Tuesday with a clipper low dropping
southeast out of the Great Lakes and into the area late Tuesday
night into Wednesday. Solutions vary significantly with the
magnitude of the cold air to follow.
Temperatures will fall Sunday into early next week with highs in
the 30s for Monday and Tuesday with lows generally in the 20s.
For the time, the NBM temperatures that were used for the
midweek period are close to normal levels, however, there is
guidance that is much colder. For example, the NBM box and
whisker plots for high temperatures Wednesday at KISP, varies
from 27 to 42 with lows that morning ranging from 18 to 36. The
12Z ECMWF and to a lesser extent the Canadian, bring a piece of
the polar vortex southward with 85h temps around -20C by
Thursday morning. The ECMWF cuts off the vortex across the
Northeast with cold air persisting through the end of the week
with a gradual moderation. There is a lot of spread in the
guidance with the evolution of the upper air pattern next week
behind the storm system. However, it looks highly amplified
and blocky by the end of the week.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
A frontal boundary remains in the vicinity through tonight as
a wave of low pressure tracks northward, with another wave
developing off the Delmarva by morning, tracking east during the
day Friday.
Low confidence forecast with respect to flight categories and
any timing of changes in ceilings and visibilities. Any VFR
conditions will be brief over the next few hours with conditions
lowering back to IFR later this evening with -RA moving in. IFR
with pockets of LIFR possible through the day Friday, with any
overall gradual improvement closer to 0z Sat.
Winds relatively light through this evening and variable in
direction. The winds become more ENE late tonight and get closer
to 10 kt for city and coastal terminals approaching the morning
push. The winds will then become more NE and N on Friday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Varying conditions for the next few hours from VFR and MVFR with
exact timing to prevailing MVFR and IFR possibly being off by
+/- 2 hrs. LIFR possible tonight and on Friday, but confidence is
lower for KLGA and KEWR.
OUTLOOK FOR 0Z SATURDAY THROUGH TUESDAY...
Friday night: IFR or lower cond are possible in areas of fog
developing. Low confidence with respect to the timing and
coverage of fog.
Saturday: Early morning IFR or lower becoming VFR by mid to
late morning.
Saturday night: Rain developing with MVFR to IFR cond.
Sunday: MVFR or lower cond in rain. Potential for snow to mix in
N and W of the NYC terminals, with IFR possible by early
evening. NE winds G20-30kt.
Monday: MVFR or lower cond. Chance of rain and snow in the
morning. N winds G20-25kt.
Tuesday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
Dense Fog Advisories have been replaced by a Marine Weather
Statement to highlight the potential for patchy dense fog this
evening. As east wind increase and dew points lower, this will
become less of an issue.
SCA remains in effect for the ocean waters for late tonight
into Fri morning, as NE-E flow gusts up to 25 kt and seas build
to 5 ft.
SCA conditions are also likely Sunday into Monday, with NE gales
possible on the ocean and eastern Sound/bays Sunday night. Ocean
seas build to 5-10 ft Sunday night into Monday. Seas will likely
linger above 5 ft on the ocean through midweek.-- End Changed Discussion --
&&
.HYDROLOGY...
There are still no significant hydrologic concerns attm.
Additional rainfall of up to 1/2 inch expected tonight into Fri
morning. Another 1/2 to 1 inch will be possible late Saturday
night into Monday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 1 AM to noon EST Friday for ANZ350-
353.
Small Craft Advisory from 1 AM to 10 AM EST Friday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/DW
NEAR TERM...BG/DW
SHORT TERM...BG
LONG TERM...DW
AVIATION...JE
MARINE...BG/DW
HYDROLOGY...BG/DW