000
FXUS61 KOKX 221801
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
101 PM EST Fri Dec 22 2023
.SYNOPSIS...
High pressure building from the north today will move offshore
to begin the weekend. A weakening warm front approaching
Saturday night will lift north on Sunday. High pressure will
then reestablish itself late Sunday into Christmas Day before
moving offshore on Tuesday. A frontal system will likely affect
the area from Tuesday night into the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Look for the current dry stretch of weather to continue with
high pressure building and spreading down from the north. High
and some mid level clouds will continue to stream in through
this evening as a 500 mb ridge axis approaches. These clouds
will be more noticeable for the NYC metro area and points west.
Temperatures will only get to the mid/upper 30s today with a dry
Canadian air mass in place despite a good amount of sunshine.
More of an increase in clouds takes place tonight, more so late
with the passage of the mid level ridge axis. The timing of the
advance of mid level clouds will ultimately determine how much
radiational cooling takes place, and thus how low temperatures
ultimately get. Either way, a seasonably cold night takes place,
with lows from the 20s to lower 30s.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
High pressure offshore will continue to linger throughout the
weekend. A dampening shortwave will approach from the west,
thus look for more in the way of clouds, especially mid level
clouds. A light southerly flow begins with high pressure further
offshore. Therefore temperatures should rebound and actually
get a few degrees above normal, with mainly lower 40s across far
northern areas, with middle and upper 40s elsewhere.
For Saturday night skies will be mostly cloudy as the weakening
shortwave begins to make it way in. The weakening of the
shortwave shows up more at the 700 mb level. It will be
difficult to moisten up the column enough to get any appreciable
precipitation. Model fcst soundings continue to show pockets of
drier air at various levels in the lower half of the column.
Thus a few light showers, or even sprinkles / drizzle remains
possible. Overall there will be little lift and the warm front
off to the west appears to experience frontolysis / weakening,
and thus precip amounts will be quite low to non- existent for
later Saturday night into Sunday.
For Sunday what is left of the warm front dissipates and lifts
north of the area. A milder Pacific based air mass moves in on
a westerly flow behind the lifting out system. Temperatures
should remain a few degrees above normal despite some cloud
cover. Most places should get into the middle and upper 40s for
daytime maxes. Have followed NBM and consensus guidance closely,
with Low end Chance to Slight Chance PoPs for late Saturday
night into Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The forecast in the extended has not changed too much over the
last 24 hours.
Key Points:
* Dry conditions expected for Christmas Day.
* Above normal temps early to mid week.
* A progressive rain event likely Tuesday night into Wednesday,
but there remains significant model spread on rain and wind
details. At this point the probability of this being a high
impact event is very low.
Complex upper air pattern across CONUS over the next several
days as a train of northern stream shortwaves moving through
southern Canada interact with a closed upper low coming into the
western US today. The general outcome of these interactions is
development of a deep central US trough early next week sliding
into the eastern US by mid- week. There is quite a bit of model
spread on the details of this trough, particularly intensity and
location of the closed low or lows over the Great lakes area,
anchoring this trough.
At the surface, general agreement on a primary area of low
pressure developing over the Central US and tracking into the
Great lakes early to mid week, with its associated frontal
system approaching the area late Tuesday and working through Wed
into Wed Night. Quite a bit of model spread on intensity of
primary low and potential development of secondary intensifying
low along the coastal plain (tied to the eventual closed low
evolution), which manifests in varying solutions of rain and
wind details.
NBM probabilities for greater than 1 inch of rain in a 12 hour
period remain at or below 10 percent. With that said, model
solutions with quicker secondary development along the coastal
plain (00z GFS) do indicate potential for over 1" of rain in 12
hrs with deep lift of a gulf/subtropical moisture feed (+2 STD
PWATS). Solutions with later and/or weaker secondary development
(00Z ECMWF) indicate a lighter event. With recent back to back
rainfall events, streamflows and soil moisture will likely
continue to run above normal during this time, so will bear
watching. NBM probs of 40-kt gusts (wind advisory) are below
5%, with even stronger 00Z GFS solution depicting only a
marginal signal for strong winds.
Models differences increase further with the evolution of the
upper trough for late week into weekend. This could continue
an unsettled pattern with a gradual cooling trend.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
High pressure remains in control through Saturday. A weakening
area of low pressure approaches from the northwest Saturday
night.
VFR. Generally light and variable winds through tonight. Light
S/SE winds developing late Sat AM, speeds at or under 5 kt.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Most likely direction would be E/NE less than 5 kt for PM push.
No unscheduled amendments expected.
OUTLOOK FOR 18Z SATURDAY THROUGH TUESDAY...
Saturday PM: VFR.
Sunday: MVFR possible, with isolated showers. Low prob for
-FZRA for KSWF late Sat Night/Sun AM.
Christmas Day: VFR.
Tuesday: Becoming MVFR or lower late, increasing likelihood for
rain.
Wednesday: MVFR or lower with rain.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA cond prevail with N flow 10 kt or less, ocean seas 3-4
ft attm, lowering to around 3 feet on Sat, and closer to 2 ft
on Sunday.
Sub-SCA conds then continue through Tue as high pressure slowly
slides east through the waters. Next chance for SCA cond for
the ocean and possibly all waters will comes Tue night into mid
week with a frontal system.
&&
.HYDROLOGY...
There is still lingering flooding along the Passaic River
(warnings handled by WFO PHI), the Housatonic River (warnings
handled by WFO ALY), and the Connecticut River (warnings
handled by WFO BOX). Otherwise, no hydrologic impacts are
expected through Tuesday.
Rain is likely from Tue night into Wed night. Low predictability
continues on rainfall amounts and therefore hydrologic impacts.
Stream flows and soil moisture will likely continue to run above
normal during this time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/BG/NV
NEAR TERM...JE/BG
SHORT TERM...JE
LONG TERM...NV
AVIATION...DR
MARINE...JE/BG/NV
HYDROLOGY...JE/NV