000
FXUS61 KOKX 021341
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
841 AM EST Sat Dec 2 2023
.SYNOPSIS...
The area will reside under weak high pressure today between
frontal systems located to the north and south. Developing low
pressure over the Mid Mississippi Valley tonight heads up into
the Great Lakes through Sunday, with a secondary low developing
to the south of the area. Both lows lift north and east Sunday
night into Monday, dragging a cold front through the area. High
pressure returns for Tuesday. Another wave of low pressure
develops off the Middle Atlantic coast Wednesday, followed by
high pressure for Thursday. The next frontal system may approach
next Friday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
An amplifying shortwave trough over the Plains today will become
a player later tonight into Sunday, but in the meantime the
forecast area will reside under weak high pressure. A weak cold
front sags south across the the Northeast today, while another
frontal system offshore will be stalled to the south and east.
After some morning clouds and fog, there very well could be
some breaks in the cloud cover. For the time, highs are forecast
to be mainly in the lower to mid 50s, but a few warmer readings
are possible, especially if more sun is achieved. Wind will
light W/SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
A confluent upper flow across eastern Canada, ahead of an
amplifying trough over the mid section of the country, will
allow for high pressure to remain in place across eastern
Canada. This will allow a dissipating cold front to get close to
the area tonight or pass just to the south. Lows will be mild
in the 40s. At the same time, an amplifying shortwave trough
lifts across the Mid Mississippi Valley tonight and across the
Great Lakes on Sunday. At the surface, developing low pressure
follows a similar track with a secondary low developing to the
south of the area on Sunday. A deep SW flow aloft and
strengthening low-level easterlies across the area will allow
for a decent overrunning rain event starting late tonight and
continuing through much of the day Sunday before drying out at
night. Rainfall amounts across the area will average between
0.75-1.00". East winds and rain will keep temperatures on
Sunday from getting any higher than the upper 40s inland and the
lower 50s along the coast.
A double-barreled low structure from the eastern Great Lakes to
east of New England will lift north and east Sunday night into
Monday with drying conditions and a gusty west flow to follow.
Modest cold advection follows with temperatures returning to
more seasonable levels.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
High pressure briefly returns for the forecast area Tuesday. A weak
surface low dives south from the Northern Plains into the mid-West
Monday night, while the flow aloft within the upper trough begins to
amplify Tuesday into Tuesday night as energy is progged to dive
southeastward towards the coast. Additionally, a weak cold front or
surface trough moves through Tuesday. This surface feature will move
through dry. The surface low weakens as it passes south and west,
with a secondary low developing off shore by Tuesday night. A large
majority of the global models and ensembles keep the secondary low
pressure development well south and east off the Middle Atlantic
coast late Tuesday night into Wednesday. However, there are some
ensembles members that have an inverted trough near the area or the
low close enough to support a slight chance (20 percent) PoP. Based
on the currently modeled pattern, the upper trough amplification
occurs too far offshore for any impacts to the region. Temperatures
Tuesday will be in the lower to middle 40s and then only upper 30s
to middle 40s on Wednesday.
The mean upper trough should push offshore later Wednesday into
Thursday. The deterministic runs diverge for the end of the week,
but ensemble means indicate a near zonal flow aloft with some
potential of a frontal system to approach on Friday. The forecast
remains dry with surface high pressure largely in control. Highs in
the upper 30s to lower 40s Thursday trend closer to normal on
Friday.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
The area will reside under weak high pressure between multiple
frontal systems today. Another low tracks west of the area late
tonight into Sunday, with a secondary low approaching from the
south.
Shifted later the improvement times in the TAF by a few hours.
Mostly IFR with some LIFR is occurring this morning. Expecting
prevailing IFR, mostly due to ceilings before 15Z.
Thereafter, improvement to MVFR between 15Z and 18Z, and
perhaps a period of VFR by 18Z-20Z, then MVFR and lower develops
again after around 00Z Sunday. NYC terminals and KSWF are
forecast to be the first to improve to MVFR (by 15Z) with other
terminals improving to MVFR between 16Z and 18Z. There is
considerable uncertainty in vsby and cigs forecast during the
TAF period.
A light SW or variable flow into this morning, picking up slightly
but still below 10 kt today. Winds become light and variable after
00Z Sun, but should generally shift to the W, then NW, and
finally NE by tonight. Winds increase to around 10 kt just prior
to 12Z Sunday.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for changing VIS/CIGS thru the TAF period as
there is considerable uncertainty in the forecast.
OUTLOOK FOR 12Z MONDAY THROUGH WEDNESDAY...
Monday: Mainly VFR. W winds G20-25kt, becoming more NW at night.
Tuesday: Mainly VFR. NW winds G15-20kt.
Wednesday: Mainly VFR. N winds G15-20kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA issued for the ocean waster for Sunday into Sunday night.
While a weak W/SW flow will prevail across the waters today,
guidance shows a period of about 6-8 hours where a 5 ft
southerly swell could enter the ocean waters east of Fire
Island Inlet. If this occurs, it looks to be mainly across the
outer waters and would be during the afternoon and early
evening hours before subsiding back below 5 ft. For the time,
since the seas are marginal, have held off on the issuance of a
SCA. However, a strengthening easterly flow late tonight into
Sunday will likely bring SCA conditions to the waters on Sunday.
Winds will then shift to W/NW Sunday night with SCA conditions
possibly lingering into Monday.
5 ft waves and 25 kt gusts are possible for the ocean waters
Monday night as a surface trough moves through. The 5 ft waves
will mainly be for the outer ocean waters. Thereafter, sub-SCA
conditions expected on all waters through Thursday.
&&
.HYDROLOGY...
0.75-1" is expected late tonight into Sunday night. There are
no hydrologic concerns given this is a relatively long duration
event.
No hydrologic impacts are expected next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 9 AM Sunday to 6 AM EST Monday for
ANZ350-353.
Small Craft Advisory from 9 AM to 10 PM EST Sunday for ANZ355.
&&
$$
SYNOPSIS...JP/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JP
AVIATION...JM/JP
MARINE...JP/DW
HYDROLOGY...JP/DW