discussion on 2024-03-27

000
FXUS61 KOKX 272345
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
745 PM EDT Wed Mar 27 2024

.SYNOPSIS...
-- Changed Discussion --A cold front continues to approach from the west tonight. This
front will weaken and eventually move across Thursday. The front
and a developing area of low pressure to the southeast of this
front will move east of the region Thursday night. The low then
moves northward into the Canadian Maritimes Friday. A clipper
type system passes to the south and east late Saturday and
Saturday night. High pressure briefly returns Sunday before
another low pressure system impacts the region Monday through
Wednesday.-- End Changed Discussion --

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --While there is a break in the rain across northeastern New
Jersey and the NYC metro another area of rain will be moving
into the area from the southwest, so have maintained the
categorical probabilities.

A cold front continues to approach from the west.

Upper level jet streak SW to NE continues to approach from the
west tonight. From forecast models, it appears that the local
region gets closer to the right rear quadrant of this jet streak
late tonight into early Thursday morning. There will be
increasing divergence aloft, with vertical lift increasing
tonight. Rain will overspread the region from west to east,
intensifying overnight into early Thursday morning. Rain looks
to be mainly stratiform.

At the surface, the cold front continues to approach tonight while
simultaneously weakening. Layer precipitable water reaches near
1 to 1.2 inches, above climatology.

Low temperatures are a blend of consensus of raw model data and
the NBM 50th percentile, staying in the low to mid 40s.-- End Changed Discussion --

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Aloft on Thursday, the upper level jet streak will continue to
be maximized north and west of the region, thereby with the
local region remaining near the right rear quad. On a larger
scale, the upper level trough becomes more negatively tilted.
Meanwhile at the surface, the cold front will continue to weaken
and move across the region during the day.

The front may very dissipate during the afternoon. During the
afternoon, low pressure in the Atlantic will be moving northeast and
will become more of a factor in terms of the local weather. The
forecast has more northerly flow across the entire area Thursday
afternoon, but not that gusty until towards the evening.

High temperatures Thursday are a blend of consensus of raw model
data and the NBM, only getting into the upper 40s to lower 50s.

Rain will continue through the day especially along the coast
where divergence aloft appears greater in the models. The
divergence is less across the interior areas and with drier air
moving in, chances for rain will lower during the afternoon
across these interior locations, mainly across interior
Northeast NJ and the Lower Hudson Valley.

For Thursday night, rain holds on across the coastal areas,
especially Eastern Long Island and Southeast CT. Colder and
drier air will advect in from the north. May even have some
chances of snow mixing in across parts of the region before all
precipitation comes to an end. Winds will become gusty from the
north as low pressure deepens out in the Atlantic getting east
of the 40N/70W benchmark and high pressure building in from
South Central Canada. Gusts up to near 30 mph are forecast and
higher gusts are possible, perhaps up to near 40 mph. Forecast
lows are mainly in the mid to upper 30s.

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
No significant changes in the long term period, as precipitation
will be ending across the eastern portion of the forecast area
Friday morning. With near zonal flow a clipper type system is
expected to quickly approach Saturday afternoon and pass to the east
and south Saturday night, as the associated upper trough phases with
the low over the Canadian Maritimes. Zonal flow become reestablished
Sunday night and yet another upper trough and surface frontal system
will be quickly approaching for Monday. Initially, a warm front will
move toward the area Monday, and then the associated low will move
slowly eastward into the region Tuesday and Wednesday. With near
seasonal temperatures through much of the extended period, except
slightly above for Saturday and Sunday, all liquid precipitation is
expected. And NBM temperatures looked reasonable through the
extended and were used.

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --A cold front slowly approaches tonight from the west. A wave of low
pressure then advances along it from the south into Thursday.

Mainly VFR to start early this evening, though ceilings and
vsbys will gradually lower as a steady rain develops overnight.

Delayed timing of category declines a couple of hours, but still
anticipate MVFR by 3Z or so, and IFR toward 6Z for most
terminals. LIFR conditions will be possible after this time as
well, though coastal and outlying terminals (KISP, KGON, KBDR,
KHPN) may have a higher chance of seeing LIFR cigs into
Thursday morning. IFR conditions likely persist thru the day
Thursday with steady rain. Slight improvements to MVFR are
possible Thursday afternoon for the NYC terminals, becoming more
likely toward 00Z Fri. A return to VFR is expected shortly
thereafter.

Winds will remain fairly light and a bit variable in direction
at around 5 kt overnight and into the Thursday morning push.
Winds then shift to the NNW and increase to 10-15kt Thursday
early afternoon. Gusts develop toward 00Z Fri, upwards of 20 to
25 kt thru Thu night.

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

Timing of category changes may be off by several hours.

LIFR cigs possible overnight but timing and coverage uncertain.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...

Thursday night: MVFR or lower to start, gradually improving to
VFR overnight as rain comes to an end. Increasing N flow, gusts
20 to 25 kt.

Friday: MVFR early, becoming VFR in the afternoon. Slight chance
of rain early for KISP and KGON. NW wind gusts 20-25 kt.

Saturday: Mainly VFR during the day. Chance of showers and MVFR
at night, possibly mixed with snow for KSWF. W-NW wind gusts
20-25 kt day. Gusts diminish at night.

Sunday: Mainly VFR. NW wind gusts 15-20 kt afternoon into evening.

Monday: MVFR possible with a chance of showers.

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

.MARINE...
-- Changed Discussion --Winds are light and variable on the waters, and made only minor
adjustments to the winds.

SCA for ocean seas continues, although it is becoming more
marginal for seas for western ocean, Sandy Hook to Fire Island
offshore waters. To the east, SCA for ocean seas extended
through the day Thursday due to higher seas near 5 ft. For
Thursday night, pressure gradient tightens with SCA wind gusts
expected for all waters and even the potential for gales across
the ocean. Gale watch for the ocean has been hoisted for
Thursday night with SCA for non-ocean waters.

Small craft advisory gusts will be ongoing across the forecast
waters Friday as deepening low pressure tracks northward into the
Canadian Maritimes. There is a chance that gusts could approach gale
force on the eastern ocean waters late Friday as the low deepens.
SCA gusts will continues into Friday night on all the waters except
for New York Harbor as conditions will be gradually improving from
the west and south during Saturday into Saturday evening as the low
tracks farther to the north through eastern Canada and weakens, as a
clipper type system approaches Saturday night. A light flow is
expected Sunday through Monday as high pressure moves through the
forecast waters and conditions remain below advisory levels across
the forecast waters.-- End Changed Discussion --

.HYDROLOGY...
Around 1 to 1.5 inches of rain expected tonight through Thursday
night. With mostly a steady stratiform rainfall, not expecting
any significant flooding from this. Any locally heavier rainfall
could produce some minor nuisance flooding in poor drainage areas
but that is it.

Otherwise, no hydrologic impacts are anticipated into the
middle of next week.

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM Thursday to 6 AM EDT Friday for
ANZ331-332-335-338-340-345.
Small Craft Advisory until 6 PM EDT Thursday for ANZ350-353.
Gale Watch from Thursday evening through late Thursday night
for ANZ350-353-355.
Small Craft Advisory until 8 AM EDT Thursday for ANZ355.

SYNOPSIS...JM/MET
NEAR TERM...JM/MET
SHORT TERM...JM
LONG TERM...MET
AVIATION...DR
MARINE...JM/MET
HYDROLOGY...JM/MET