162
FXUS61 KOKX 271658
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1158 AM EST Fri Dec 27 2024
.SYNOPSIS...
High pressure moves offshore this afternoon ahead of an approaching
frontal system. A warm front approaches Saturday and moves
through on Sunday, with a cold front moving through late Sunday
night into Monday. Another frontal system is forecast to move into
the area for the middle of next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Latest surface analysis clearly shows the cold air having a difficult
time being scoured out across the Mid Hudson Valley down into
the KSWF and KMGJ in Orange County. While there is a thin veil
of cirrus across the area, most locations are now above
freezing and some already warmer than previously forecast.
Latest HRRR soundings show it being deeply inverted above the
surface with plenty of warm for a rain event that will move in
later tonight. The question will be how much warmer can these
locations get inland as it will take some time to scour out the
low levels due to a weak return.
Otherwise, a light SW flow develops develops this afternoon.
Highs will be in the upper 30s to around 40 at the coast, and
the low to mid 30s inland. Some locations in northern portions
of Orange and Putnam counties in NY may not get above freezing.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Although high pressure shifts offshore this afternoon, a very weak
pressure gradient remains across the area and results in only
very weak return flow. By 06z tonight, the high is progged to be
centered about 200nm offshore and the flow across the area will
still likely be under 5 kt. Because temperatures don`t get too
high during the day, the interior will be able to drop to below
freezing before any significant cloud cover/significant warm
advection kicks in.
Off to the west, a shortwave trough lifts into Central NY out ahead
of a stronger shortwave that will lift into the Great Lakes. Warm
advection precipitation enters the western part of the area sometime
between 03z and 06z. Forecast soundings are very warm aloft (5
to 7 C around 900mb) and all the precipitation will fall as
rain or freezing rain. Confidence has increased in freezing rain
across the interior as the latest hi res guidance continues to
be in good agreement on timing and forecast temperatures were
lowered. A Winter Weather Advisory has been issued. The highest
confidence is across Orange, Putnam and northern Fairfield
Counties, where up to a tenth of an inch of ice accumulation is
possible. Went with some cooler guidance for temperatures,
especially on Saturday morning where the NBM is likely warming
up valley locations too quick. Included the CT coast, southern
Westchester, eastern Essex and Eastern Union in the HWO as brief
freezing rain can not be ruled out. Temperatures are marginal
in these locations and subsequent shifts will have to monitor
trends in guidance. All plain rain is expected across NYC, Long
Island and the NJ metro area.
There is still some question in how long it takes for ground
temps to rise above freezing. The thinking for now is that
interior CT and Orange County will hold on the longest,
especially in the valley locations, through potentially mid
morning. By late morning all plain rain is expected everywhere.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A warm front will be in the vicinity of the area Saturday night into
early Sunday morning. This will likely be the focus for some rain
showers over much of the area, but intensity should be light with
showers generally more scattered than widespread. The area then
become warm sectored on Sunday, with an intensifying low pressure
system over moving over the Ohio Valley and into the Great Lakes
region. This may result in additional scattered shower activity,
though depending on how deep into the warm sector the area is in,
some areas may be dry during the day on Sunday, especially areas to
the south and east, such as eastern Long Island and southeastern CT.
By Sunday night, the strong cold front begins to approach the area
from the west. As the low pressure strengthens and pushes northeast
into Southeastern Canada to the northwest, the cold front will
slowly make its way through the area into Monday. Deterministic
models are coming more in line with the front moving through by late
Monday morning into the early afternoon hours, though the Canadian
is still lagging a few hours behind the ECMWF and GFS. Light to
moderate rainfall is expected for much of the area Sunday night with
persistent strong southerly flow advecting warmer air into the area.
High temperatures both Sunday and Monday are expected to be in the
lower to middle 50s, well above average for this time of the year.
The system exits the area by Monday night allowing for weak high
pressure to move overhead before quickly departing as another
moderately strong albeit much quicker low pressure system moves in
from the southwest into the middle of next week.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
High pressure remains over the area today, then slides offshore
tonight as a warm front approaches.
VFR today with a low probability of MVFR cigs developing for S
coastal terminals this aft/eve. MVFR to IFR conditions expected late
tonight through the end of the forecast period.
Variable to light N/NE winds late this morning, becoming light S to
SE flow or variable after 18Z. Speeds generally 5 kt or below
through the TAF period. Light precipitation moves in after 06Z
tonight, with steadier precipitation towards daybreak Saturday.
Conditions at the more northern terminals may be cold enough at the
start for some freezing rain. The best chance for this is at KSWF.
However, a brief period of -FZRA showers is possible for KHPN and
KTEB and covered this with a tempo group. Plain rain is expected
after 08Z for these terminals. There is an even less chance for brief
-FZRA at KBDR and KGON, but did not include in TAFs due to the very
low chance of occurrence.
NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
No unscheduled amendments expected through this afternoon. Low prob
for MVFR cig development for the eve push. A brief period of -FZRA
is possible at KTEB between 06-08Z tonight, with plain rain expected
after 08Z.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
Saturday morning: Becoming MVFR/IFR with light rain developing from
west to east for city/coastal terminals aft midnight. -FZRA likely
developing aft midnight thru Sat AM push for KSWF, with up to a
tenth of an inch of ice accretion on untreated surfaces. Low chance
of LIFR conditions late Sat AM.
Saturday afternoon into Sunday: Period of -RA & DZ likely with IFR
and LIFR conds.
Sunday Night into Mon Morning: -RA/RA and IFR conds. Chance of LLWS.
S winds with gusts abv 30kt.
Monday Afternoon: Becoming VFR with W winds.
Tuesday: MVFR or lower in -RA likely.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
With high pressure over the area, winds and waves remain below SCA
criteria through Saturday.
The frontal system will move across the area waters Sunday and
Monday, with SCA conditions possible on all waters from Sunday night
through Monday morning as winds gusts increase to near 25 kt. Seas
build to 5-9 ft on the ocean waters late in the day Sunday into
Monday, slowly diminishing Monday morning into Monday night.
Conditions fall below SCA levels on Tuesday, however this may be
short lived as another frontal system approaches for Tuesday night
and Wednesday.
&&
.HYDROLOGY...
There are no hydrologic concerns through next week at this time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Weather Advisory from 11 PM this evening to 11 AM EST
Saturday for CTZ005>008.
NY...Winter Weather Advisory from 9 PM this evening to 9 AM EST
Saturday for NYZ069-070.
Winter Weather Advisory from 9 PM this evening to 11 AM EST
Saturday for NYZ067-068.
NJ...Winter Weather Advisory from 9 PM this evening to 9 AM EST
Saturday for NJZ002-004-103>105-107.
MARINE...None.
&&
$$
SYNOPSIS...JP/JT/DW
NEAR TERM...JT/DW
SHORT TERM...JT
LONG TERM...JP
AVIATION...JE
MARINE...JP/JT
HYDROLOGY...JP/JT