000
FXUS61 KOKX 251436
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
936 AM EST Thu Jan 25 2024
.SYNOPSIS...
A warm front has lifted to the north of the area this morning
and will drop south through our area as a cold front this
afternoon/evening. The front lingers over/near the area Thursday
night. A wave of low pressure and a cold front move east of the
area during Friday. The region is in between systems to start
the weekend. Low pressure approaches for the latter half of the
weekend. The low is forecast to strengthen southeast of Long
Island Sunday night into Monday. High pressure returns
thereafter for early to the middle of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
For the 530AM update, temperatures and dewpoints were adjusted
to account for current observations and trends, with many areas
trending warmer. 2 mile visibilities were extended across the
area a few hours earlier than forecast to account for
observations. The front has sagged a little south in the last
few hours, allowing for more steady rainfall for southern
locations. Previous discussion as follows...
A warm front has lifted north of the area this morning aided by a
strong SW LLJ. GOES-16 Longwave IR channel shows the boundary
very well associated with the colder cloud tops where most
precipitation is currently concentrated. Most of the current
rain in our area is light for northern areas near the warm front
and more like on-and-off drizzle for southern locations. This
will change as the warm front starts to advance southward helped
by an exiting low over the Canadian Maritimes and strengthening
high pressure to our north in the low`s wake. The warm front
will push back over the area this afternoon/evening as a cold
front, bringing more consistent light rainfall in the afternoon.
As the front situates itself south of us in the evening and
early night, much of the rainfall will be concentrated offshore
to the south, with more spotty, isolated rain chances, mostly
for southern areas closer to the boundary while northern areas
remain drier.
Areas of fog will continue to persist and may even redevelop until
the front clears to the south of the area Thursday afternoon and
evening. Before doing so, warm air will continue to filter in with
the warm front still situated to the north, leading to highs today
in the low-50s across the area.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
The front will stall and situate itself over our area yet again
Thursday night. Another wave of low pressure will track along this
frontal boundary from the southwest bringing more rainfall through
the night on Thursday. Areas of fog will redevelop Thursday night
and early Friday morning with this wave of low pressure as dewpoint
depressions will be very low and rainfall may not be heavy enough to
mix it out.
A second area of low pressure to our west with a cold front will
approach us Friday afternoon clearing any lingering rain and allow
drier air to filter in. In total, Thursday morning through Friday
afternoon, about 0.5-1.0 inches of rainfall is expected with higher
totals south and lower totals north.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
* Rain latter half of weekend, ending as snow potentially late
Sunday night into Monday. Potential for accumulating snow
Sunday night into Monday along with gusty NE winds.
Confidence low in the forecast.
* Turning colder Sunday into early next week. Forecast highs
only in the 30s for Monday and Tuesday.
Model uncertainty likely with wavering positions of low pressure
southeast of Long Island and varying magnitude of low pressure. So,
this will make for wide ranges of precipitation forecasts and how
much of the region will get snow versus rain or a mix of the two.
Also, this will make for wide ranges of snowfall in the
forecast. Because of these factors, the forecast confidence is
low and the new forecast incorporates the previous forecast to
mitigate drastic oscillations of precipitation and winds from
one forecast to the next.
For example, LREF dataset depicts greatest uncertainty in
precipitation from Sunday afternoon through Sunday night
comparing differences between max and min members as well as
between the 25th and 75th percentile.
Aloft, mid to upper levels depict a deepening trough with
positive tilt Saturday into Saturday night. By Sunday, the
upper jet extends from Gulf of Mexico to southern portions of
Canadian Maritimes. The jet streak goes east of the local
region Monday and the jet remains south of the region early to
the middle of next week.
The mid levels show the trough moving into the area Sunday,
with most positive vorticity advection moving across Sunday
night into early Monday. Trough pattern overall on average remains
across the region early to middle of next week.
For Saturday, the local region will be in between low pressure well
out in the Atlantic and another one developing in the SE United
States. This low to our south and west will be the main player in
terms of the weather forecast and for potentially the impactful
weather of the long term.
The low is forecast to move northeast along the Appalachians
Saturday night into Sunday. Then, on Sunday, the low moves east to
the mid-Atlantic coast and eventually offshore for early Sunday
evening. The low thereafter deepens as it continues to move in a
general eastward direction Sunday night through Monday.
High pressure builds in from the north for Monday night. However,
this high quickly weakens Tuesday into mid week. Mainly dry and cold
conditions with airmass moderating by midweek with temperatures
trending warmer.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Frontal boundary eventually moves across the region and farther
south today and then returns back north tonight.
With a warm front to the south of the region and another frontal
boundary to the north, with a wave of low pressure tracking
through the area, or just to the south, conditions vary from IFR
to MVFR, and even briefly VFR. With the rain ending as the wave
of low pressure passes to the south and east, conditions are
expected to briefly improve to MVFR across the terminals.
However, with another round of rain moving in late this evening
into tonight, and early Friday conditions return to IFR and
possibly LIFR.
With the potential for categories to fluctuate and timing
differences and spatial differences in categories that could
vary a few hours from forecast, the forecast has low confidence.
Winds relatively light through the period, near 10 kts or less.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There could be fluctuations between IFR and MVFR today into
early tonight. LIFR will be possible at times, mainly this
evening, and tonight.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday...Chance of MVFR/IFR/rain mainly AM. Improvement to MVFR
and eventually VFR in the afternoon.
Saturday...Mainly VFR. MVFR or lower developing in rain at night.
Sunday...MVFR or lower in rain. Potential for snow to mix in N&W
of NYC terminals with IFR possible. Potential for snow for all
terminals late Sunday night with IFR possible. E-NE winds
gusting 20-25kt during day and 25-30 kt at night.
Monday...MVFR or lower. Chance of snow, mainly AM. NE G20-30 kt.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA conditions were originally expected this morning along ocean
waters, but the latest guidance and observations no longer support
the issuance of a Small Craft Advisory. Waves will reach 4 feet on
ocean waters with wind gusts SW 20-24 kts.
Thursday afternoon through Friday night SCA conditions are not
expected.
Sub-SCA conditions expected Saturday through Saturday night. SCA
conditions become more likely Sunday and Sunday night. Potential for
gales on ocean, Eastern LI Sound and Eastern LI Bays Sunday
night into Monday with otherwise SCA conditions. Monday night
forecast to have more SCA conditions as gales diminish.
Ocean seas build to 5 to 10 ft Sunday night into Monday.
&&
.HYDROLOGY...
In total, Thursday morning through Friday afternoon, about 0.5-1.0
inches of rainfall is expected with higher totals south and lower
totals north. There are no significant hydrologic concerns at this
time.
No hydrologic impacts are currently expected Friday through
early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JM/BR
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...JM/MET
MARINE...JM/BR
HYDROLOGY...JM/BR