000
FXUS61 KOKX 232341
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
641 PM EST Sat Dec 23 2023
.SYNOPSIS...
High pressure centered east of New England will drift a little
farther east tonight as a weakening warm front and upper level
disturbance approach. The front will dissipate nearby on Sunday,
allowing the high to reestablish itself from the east on
Christmas Day as the upper level disturbance moves across from
the north. The high will then move back out into the Atlantic
and slightly weaken Monday night through Tuesday. Low pressure
will then approach Tuesday night into Wednesday, pass nearby
Wednesday night, then pass to the northeast on Thursday. A cold
front will approach Friday into Saturday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Overcast skies (mostly mid level clouds) have spread across the
entire CWA. MRMS shows some radar returns across parts of Orange
County that are likely not reaching the ground due to dry sub-
cloud air.
Model guidance has trended drier with the approaching front, and
have chance PoP only for parts of Orange County for tonight.
Temps there should be aob freezing, so cold enough for some
spotty light mixed wintry precip, with p-type of any precip
more likely to be light snow before midnight and then light
sleet or freezing rain after midnight as low levels warm up. Any
QPF should be on the very light side, only a couple hundredths
of an inch at most. HWO already mentions this potential, and due
to the spotty nature of any expected precip will not be issuing
winter headlines but may need SPS at some point.
Low temps tonight should range from 25-30 inland, to 30-35 most
elsewhere, to the upper 30s in NYC. Lows are likely to be
reached this evening before remaining nearly steady overnight.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
The weakening front may still produce some spotty light precip
on Sunday mainly inland N of NYC, while its associated upper
level disturbance moves into upstate NY into a building upper
level ridge and cuts off. High temps should range from the
upper 30s well inland to the upper 40s across NYC metro/Long
Island.
The weak cutoff low should then turn S across New England and
the CWA from late Sunday night into Christmas Day, and maintain
mostly cloudy skies. Lows Sunday night will be from the lower
30s well inland to the lower 40s in NYC. Highs on Christmas Day
will be a little milder, 45-50.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Points :
* Prolonged steady rainfall mainly Wednesday into Wednesday
night, possible 1 to 2 inches.
* Warmer than normal temperatures until late week, then airmass
cools closer to normal
* Forecast changes from previous forecast, a little cooler and
PoP increased on Wednesday
The synoptic pattern still transitions from ridging to troughing
Monday night into mid week. This will be as surface high
pressure moves farther out to sea. Meanwhile, a developing
frontal low pressure system in the Southeast will approach the
area.
The large scale numerical weather prediction models do not
strengthen this system too much despite an increasing
subtropical upper level jet. The mid and upper level pattern
remains positive tilting.
The axis of the upper level trough with multiple positive
vorticity advection maxima moves into the Northeast for the
latter half of next week.
The pattern results in a more of a progressive low that does not
deepen too much. This will limit the heavy rain and thereby the
total rainfall with the midweek event. The pattern for the
latter half of the week depicts the more unsettled pattern where
there will be periodic chances for rain and/or snow showers
depending on the timing of when these vorticity maxima move in.
The troughing aloft latter half of the week will also point to a
transition to a relatively colder airmass for Friday and into the
start of next weekend.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
High pressure gradually drifts east over the Atlantic thru
Sunday.
Generally VFR for the NYC terminals the thru the TAF period.
SOme MVFR cigs will be possible well north and west of NYC
(where the best chances of precip will be) and also the far
eastern terminals (KBDR and KGON). Generally looking at some
light rain or drizzle moving through the area after midnight.
Will cover this with a tempo group. The precip looks light with
little impacts to operations. A mix with snow will be possible
at SWF if the precip occurs. There could also be some marine
stratus and fog from the ocean tonight. Again the probability
is low.
In the absence of any marine stratus on Sunday, VFR expected.
Winds will be light and variable through the TAF period.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Some variability in wind direction will be possible through the
TAf period, but wind speeds are expected to remain below 5kt.
Potential for the area to remain VFR thru the TAF period. If
marine stratus develops overnight, MVFR may linger thru 18Z
Sunday.
OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
Christmas Day: VFR.
Tuesday: Becoming MVFR aft 00Z Wed. Chance of rain aft 06Z.
Wednesday and Thursday: 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 expected through daytime Wed. SCA cond are then
increasingly likely Wed night through Thu night, mainly on the
ocean waters. Some of the non-ocean waters could see higher
gusts up to 25 kt at times.
&&
.HYDROLOGY...
River flood warnings are still in effect along the CT River
(handled by WFO BOX) and parts of the Passaic River basin
(handled by WFO PHI).
Localized minor/nuisance poor drainage flooding possible where
relatively heavier rainfall occurs mid-week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...JM
AVIATION...BC
MARINE...BG/JM
HYDROLOGY...BG/JM