000
FXUS61 KOKX 230530
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1230 AM EST Tue Jan 23 2024
.SYNOPSIS...
A weak frontal system will pass through the region on Tuesday,
then to the north and east on Wednesday, with another
disturbance following behind it Thursday into Friday. An area of
low pressure develops over the Deep South into the weekend,
likely tracking near the region early next week.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
No significant changes with the forecast remaining on track. Dew
points and temperatures have been adjusted slightly to reflect
the most recent observations and the trends of each over the
next several hours.
Water vapor shows moisture flowing nwd from the GOMEX, while Pacific
moisture streams towards TX. As the upr trof over the middle of the
conus slowly translated ewd, this moisture will begin to flow
into the cwa.
Increasing clouds tngt as moisture rounds the offshore ridge and
flows into the area. With subsidence aloft and dry llvls, the fcst
has been kept dry reflecting the NBM guidance. This is supported by
no pcpn reported across ncntrl PA into NY state with the radar
echoes this aftn.
The cloud cover should keep temps warmer than the last few nights,
with lows in the 20s to around 30 per the NBM which was used
with minor local adjustments.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
Light pcpn begins to break out during the day as a jet segment
and mid lvl wave approach. Mild temps aloft to start, so either
-ra or -fzra the initial pcpn type expected attm. Perhaps some
sleet mixed in. The -fzra is likely to be confined to the
interior n and w, where sfc temps will be harder to get abv
freezing and where pcpn is expected at the same time. The pcpn
may arrive too late across most of CT to risk any -fzra, and at
the coast it looks warm enough at onset to keep the start all
rain. Nonetheless, it is very close with timing and temps, and
there is a concern based on blended dewpoints that sfc temps
could end up colder than fcst. The fcst is already much colder
than the NBM and other guidance.
No advy attm, but one will be possible if confidence increases on
the timing and placement of any fzra, as only a trace is
required. Will include a mention in the HWO however.
As high pres traverses Quebec in the aftn, a backdoor cold front
begins to sag swwd into the cwa, allowing for the column to cool
from NE to SW on nely flow. The NAM is colder than the GFS, and
decided to go close to the NAM which had support from the HRRR.
As a result, expecting a transition to a mixed bag and
eventually snow roughly down to the CT coast and thru the Hudson
Valley into interior NJ into Tue eve.
Temps aloft then rise overnight, so a transition to an icy mix or
fzra is again likely, provided the light pcpn is still ongoing.
The lift is not particularly strong with this event, so mainly light
pcpn is expected throughout. This should keep any snowfall accums
less than an inch with the rates too low. The main hazard will be
where the pockets of -fzra develop, leading to icy spots.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
*Key Points*
* Gradual warming trend into late week, temperatures 10 to 15
degrees above normal by Friday.
* Multiple rounds of precipitation with several waves of low
pressure impacting the region through the weekend.
Region remains on the northern periphery of broad ridging over the
Eastern US to start the period. Frontal boundary meanders near the
region on Wednesday, gradually lifting back north by Thursday as
weak low pressure exits the New England coast. Soundings indicate a
warming column that should change any remaining frozen precip into
plain rain by late Wed AM. Much of the afternoon may turn out
largely dry, though as another shortwave rounds the ridge and WAA
begins to work in, additional wet weather looks to develop by the
evening. The associated surface low is progged to pass to our north
and drag a cold front through the area Thursday night into Friday
morning, with periods of rain through then.
A brief reprieve then looks likely thru Saturday with zonal flow and
weak high pressure temporarily in place. Global guidance is in
fairly good agreement in another shortwave spurring low pressure
development over the Deep South by Saturday, eventually emerging off
the Mid Atlantic coast toward the latter half of the weekend. While
confidence is low at this stage, it`s not out of the question that
ptypes could become a factor with this system locally should
Canadian high pressure build in quick enough to allow a marginally
cold enough air mass to support it. For now, capped PoPs at chance
(50%) given differences in timing and track at this stage,
otherwise, NBM was generally followed.
Despite the multiple periods of precipitation, the extended does not
necessarily look like a washout. Ensemble means prog total
precipitation thru early next week at or under 2 inches, which
occurring over several days, should help to preclude any significant
hydro concerns. In addition, the moderating flow on the backside of
the high helps to thaw out the region from the recent cold spell. A
gradual warming trend looks to peak Friday, when forecast highs are
progged in the 50s, or upwards of 15 degrees above normal for late
January.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A weak cold front sags south, meeting up with warm front from
the southwest and creating a nearly stationary front over the
region tonight into Wednesday.
Mainly a VFR forecast through the overnight and the first half of
Tuesday. MVFR/IFR conditions developing Tuesday late morning/early
afternoon in a light wintry mix mainly for KSWF. While less likely,
a light wintry mix remains possible for northern terminals, namely
KHPN, KBDR, KGON. The NYC terminals could see some MVFR ceilings in
light rain late Tuesday afternoon/early evening, but confidence not
high so covered with a Prob30. By Tuesday evening and into the
overnight , widespread MVFR or lower ceilings expected for all
terminals. -RA showers become possible overnight into Wednesday
morning for the coastal and NYC terminals but confidence in coverage
and intensity is low.
SW winds around 10 kt at the coast, but weaker at the inland
terminals, will gradually veer to the W late tonight at less than 10
kt. Some gusts up to 20 kt possible. Winds will then become light N-
NW Tuesday afternoon/early evening. Winds continue to veer to the N
then NE into the evening and the overnight.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of light precipitation Tuesday may need to be amended by 1-3
hours. Amendments likely Tuesday afternoon through evening for the
timing of changing flight categories with MVFR/IFR cigs and vsby.
OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
Tuesday Night...MVFR/IFR with a chance of light rain at the coast
and IFR at the inland terminals. A wintry mix could get down to the
CT coast. Confidence in precipitation type is low at this time.
Wednesday-Thursday Night...MVFR/IFR with periods of rain.
Friday...Chance of MVFR/IFR/rain AM. Chance of improvement to VFR in
the afternoon.
Saturday...Mainly VFR. Chance of precipitation late.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds increase tngt. The sca was expanded to all but the harbor.
Winds diminish during the day on Tue. No changes to the end
timing of the sca with the ern ocean up the longest. Winds and
seas blw sca lvls all waters Tue ngt.
Sub SCA conditions appear to continue on all waters through at least
Thursday, and perhaps into the weekend with a weak pressure gradient
in place.
&&
.HYDROLOGY...
No hydrologic impacts are expected through the weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST early this morning for
ANZ331-332-335-340-345-353-355.
Small Craft Advisory until 10 AM EST this morning for ANZ350.-- End Changed Discussion --
&&
$$
SYNOPSIS...JMC/DR
NEAR TERM...JMC/MW
SHORT TERM...JMC
LONG TERM...DR
AVIATION...MW
MARINE...JMC/DR
HYDROLOGY...JMC/DR