discussion on 2024-01-19

000
FXUS61 KOKX 191732
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1232 PM EST Fri Jan 19 2024

.SYNOPSIS...
Low pressure passes well southeast of the area today. Arctic high
pressure then builds in through the weekend. High pressure then
remains south of the region on Monday. A frontal system is then
expected to impact the area Tuesday through Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Light snow continues to be observed across the whole area. The
highest returns can now be seen just south of the area and
extending down into southern and central NJ as the whole axis
shifts east slowly. Light snow is expected through the early
evening, with the bulk falling this afternoon. Snow amounts and
the Winter Weather Advisory were not changed with this update.
Earlier, an SPS was issued to cover the Lower Hudson Valley and
Southern Connecticut as some light accumulation could cover some
untreated surfaces. The surface low can be seen quite well on
current visible satellite imagery. It is located about 350 nm
south of Long Island. The latest guidance continues to struggle
with the location of the low, with the low appearing to be just
south and east of much of the guidance.

The previous discussion follows. An expansive upper trough over
the Great Lakes will have energy rounding its southern
periphery. This will help create an inverted trough at the
surface as an extension of a low pressure system well offshore
today. Model guidance continues to place this inverted trough
and best lift to our south, mainly near southern NJ. There will
however be enough moisture and lift for the likelihood of some
snow across most of the forecast area. This will develop
generally west to east across the area this morning and end late
day into early evening.

Model QPF remains light with only 0.1 to 0.2 inches across southern
zones, and up to around 0.1 inches for most spots north of the city.
It`s appearing more likely that most spots will probably end up
below advisory criteria as chances of snow/liquid equivalent ratios
of at least 15:1 in the advisory areas are diminishing as the best
lift remains to our south and thermal profiles are a little too warm.
Will however leave the advisory up as the late day/evening commute
will probably be impacted to some extent. Additionally, there is
still a chance that the inverted trough ends up a little farther
north than modeled as models typically have difficulty nailing down
their locations - but again, this would now be occurring 12-24 hours
from the 00z model initialization time, so chances are that they
won`t be too far off.

Snow chances end by late evening with partial clearing for the
overnight hours and somewhat breezy. Low temperatures in the teens
for most spots with wind chills late at night from around 0 to 5
above.-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Upper trough axis shifts through the Northeast on Saturday into
Saturday night. Doesn`t appear to be enough moisture combined with
this cyclonic flow, so dry weather expected. Remaining colder than
normal with high temperatures only in the lower and middle 20s.
It`ll be breezy, with wind chills warming to only around 10 above
during the afternoon hours. Wind chills on Saturday night then fall
to 0 to 5 below for areas north of the city, and 0 to 5 above most
elsewhere as it remains breezy due to the relatively tight pressure
gradient over the area as high pressure builds in from the west.

The high pressure ridge axis won`t quite reach the eastern seaboard
by late Sunday night, so it remains breezy during the day Sunday.
Expect sunny conditions, but not as cold as Saturday as the boundary
layer warms in the wake of the trough aloft. Still, wind chills
average around 20 in the afternoon.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
High pressure will pass south of the region on Monday. Expect dry
conditions Monday and Monday night.

The high slides east of the region on Tuesday. This will allow the
next storm system to impact the region, mainly Tuesday night through
Thursday as a frontal system approaches. A cold front is expected to
approach from the north, gradually stalling over the region on
Wednesday, then finally pushing south of the area on Thursday. There
remains quite a bit of uncertainty this far out. This includes start
time and precipitation type.  Some areas may start off as snow or a
rain/snow mix Tuesday night before changing over to all rain by
Wednesday morning. One important player will be the position of
strong high pressure moving southeast across southern Canada into
northern New England Tuesday into Tuesday night.

Temperatures gradually moderate through the week, with highs on
Monday in the middle and upper 30s. Tuesday, highs will be in the
upper 30s and lower 40s. By Wednesday and Thursday, highs will
be in the 40s across the entire region.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --Low pressure will pass well south of the region today. This
will place the area terminals on the northern edge of an area of
mainly light snow.

Widespread MVFR/IFR conditions through the early afternoon.
Light snow (-SN) is resulting in visibilities anywhere from 1 to
3 miles for much of the area. Some localized LIFR conditions
are possible through the afternoon. -SN expected to taper off by
the early evening with conditions improving to VFR around or
shortly after 00Z.

NNE winds around 10kt today will veer to the N by early
evening, then NW after 00Z. Second half the night and Saturday
will feature gusts up to 20-25 kt.

     NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Amendments likely with flight category changes due to snow
falling across the area through this afternoon.

OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday-Sunday...Mainly VFR. N-NW wind gusts 20-30kt.

Monday...VFR.

Tuesday...Mainly VFR. Possible MVFR or lower in any rain/snow.

Wednesday...MVFR or lower possible in rain showers.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --

&&

.MARINE...
Winds begin to pick up late today with SCA conds expected on all
waters tonight - staring first on the ocean, then reaching the
remaining waters after midnight. SCA conds then continue through
Saturday afternoon. A tighter pressure gradient forms over the waters
Saturday night, solid SCA conds, and a chance of gales over the
ocean. Have issued a gale watch on the ocean as such. SCA conds
otherwise would likely continue into Sunday. There could also be
freezing spray from time to time starting late tonight.

Generally looking at sub-SCA conditions on the area waters on
Monday. Seas on the ocean may briefly build to 5 ft late Monday
night, mainly on the eastern ocean zone, with a return to sub SCA
conditions by Tuesday morning.

&&

.HYDROLOGY...
No hydrologic impacts are expected through the middle of next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Weather Advisory until 7 PM EST this evening for
     NYZ071>075-078>081-176>179.
NJ...Winter Weather Advisory until 7 PM EST this evening for NJZ002-
     004-006-103>108.
MARINE...Small Craft Advisory from midnight tonight to 6 PM EST
     Saturday for ANZ331-332-335-338-340-345.
     Small Craft Advisory from 6 PM this evening to 6 PM EST
     Saturday for ANZ350-353-355.
     Gale Watch from Saturday evening through late Saturday night
     for ANZ350-353-355.

&&

$$

SYNOPSIS...BC/JC
NEAR TERM...JC/JT
SHORT TERM...JC
LONG TERM...BC
AVIATION...MW
MARINE...BC/JC
HYDROLOGY...BC/JC