000
FXUS61 KOKX 201901
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
301 PM EDT Wed Mar 20 2024

.SYNOPSIS...
-- Changed Discussion --
A cold front will move across late this afternoon into early
this evening. Low pressure moves from Northern New England
tonight into the Canadian Maritimes on Thursday. High pressure
then builds in its wake thereafter through Friday and pushes
offshore by late Friday. Low pressure impacts the area Saturday
into Saturday night. High pressure then builds from southeast
Canada Sunday into early next week as the low slowly moves away
from the coast. Another frontal system may approach late
Tuesday.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
Mid level trough and vort max move across the region going
through early to the middle of this evening. The increase in
positive vorticity advection will enable for increasing lift. At
the surface, a cold front will be moving across the region late
this afternoon into early this evening. Showers are likely
across the region going into early this evening with a
decreasing trend after 23Z.

By around 00Z, the front should be exiting southeast of the
region across the ocean waters. Central low pressure will stay
north of the region and steepen as it is expected to move into
Northern New England tonight. The increase in pressure gradient
will drive an increasing NW flow, increasing cold and dry air
advection.

Temperatures running a little cooler than forecast so some
colder air advecting in as well as wet bulb cooling will allow
for some snow to mix in with the rain showers before all
precipitation ends. The snow showers mixing in is expected
across the interior areas with the coast staying mainly plain
rain showers. Would expect precipitation to taper off fairly
rapidly this evening as more drier air gets advected into the
region.

Slowed down the decrease of clouds late tonight that models
were conveying as there will be cyclonic flow aloft which tends
to have more clouds on average. Used a blend of NBM and MOS
consensus for lows tonight, ranging from the upper teens and low
20s across parts of the interior to upper 20s to near 30 for
much of the coastal areas.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
The frontal system then heads east on Thursday and high pressure
builds in from the OH Valley and moves overhead by Friday morning.
The high slides offshore by Friday night. Thus, both days look dry.
With ample CAA at the start of the period under continued gusty NW
flow, high temperatures will be below normal both days. Friday may
be a few degrees warmer, as return southerly flow takes hold by the
afternoon and cloud cover increases in advance of the next system.
Wind chills each night will be in the upper teens to low 20s given
the elevated winds and cold air mass.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
There has not been too much change with the forecast thinking
for the upcoming weekend into early next week. Another
significant rainfall event is becoming more likely Saturday
into Saturday night. This is due to a low pressure over the
southeast and Middle Atlantic sending subtropical moisture
northward and interacting with a frontal system slowly moving
over the northeast.

*Key Points*

*Widespread rain is expected Saturday into the first half of
 Saturday night.

*The rain may be moderate to locally heavy at times with
 potential of 1-2 inches. Current model consensus favors Long
 Island and Southern Connecticut with the highest rain totals,
 but this could change in subsequent forecasts.

*The latest NBM probability for greater than 1 inch of rain in a
 24 hour period ranges from 40 percent west of the city to
 around 60 percent across Long Island and SE CT.

*The latest NBM probability for greater than 2 inches of rain in
 a 24 hour period is not insignificant, generally 15-25 percent
 along and west of the Hudson River and 30 to 40 percent east.

*Minor flooding appears to be the greatest threat at this time,
 but it is too early to determine if there will be any impacts
 to rivers and streams.

*The rain should begin tapering off from west to east late
 Saturday night.

*Breezy conditions are likely Saturday, but strongest winds
 (gusts 25-35 mph) may occur Saturday night into Sunday,
 especially near the coast.

The main southern stream shortwave is likely to remain near the
southeast on Sunday as the progressive northern stream picks up
the deep moisture and shifts it offshore. The guidance has
become better aligned for Sunday into early next week, but there
are still questions with the evolution of the southern stream
becoming a cut-off low over the western Atlantic. There have
been several models indicating the cut-off meandering nearby or
even retrograding closer to the region. This could help send
some rain back into eastern portions of the area. However, there
are also many pieces of guidance signaling the cut-off will be
far enough east with little impact to the region. While this is
a occurring, a strong surface high will settle over southeast
Canada and ridge down over the region. The high may serve to
keep any precip offshore, especially if the stronger high
solutions verify. Due to the large amount of uncertainty with
this time period, have followed the NBM PoPs. The overall trend
however is for lowering PoPs into Sunday and then mainly dry
conditions Monday. Another shortwave may lift across the Great
Lakes next Tuesday, which could send a frontal system towards
the area. The system may have trough reaching the region,
especially if the cut-off low is still close enough to the
coast.

Temperatures this weekend into early next week look to be near
or slightly below normal.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
A cold front passes across the terminals this afternoon.

VFR with scattered showers ending 21-00z. SW-W winds around 10 kt
increase as they veer towards 21-00z with a shift into WNW shortly
thereafter and increasing with gusts 30-35kt until around 06z. Winds
diminish at little overnight before picking up again towards the end
of the Thursday morning push.

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

Winds may be stronger by around 5 kt than forecast before 21-23z and
may be veered by 20-30 degrees than forecast at times. Gusts 30kt+
may end a few hours before 06z. Chance of showers may continue
around an hour longer than forecast in TEMPO group.

OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday PM: VFR. WNW gusts 25-30kt, diminishing to around 20kt by
midnight

Friday: VFR.

Friday night: MVFR or lower developing after midnight with rain near
the coast and rain/snow inland.

Saturday: IFR and rain. SE wind gusts 20-25kt during the day with
LLWS possible city east, becoming N all areas with gusts around 30kt
at night.

Sunday: VFR. N-NE wind gusts around 25kt.

Monday: VFR. NE gusts 20-25kt.

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 expected to rapidly increase behind a cold front this
evening as the pressure gradient tightens. Associated low
pressure will strengthen as it heads into Northern New England
tonight and then will remain nearly the same strength as it
moves into the Canadian Maritimes Thursday.

SCA conditions expected going into early this evening on the
ocean with perhaps some occasional 25 kt gusts on non-ocean
waters. Then as the evening progresses, gale force wind gusts
are expected to develop on all waters, continuing through the
rest of tonight. The gales continue into Thursday morning for
most of the waters before winds decrease more into SCA range
Thursday afternoon into Thursday night.

Small craft conditions subside by early Friday as the pressure
gradient relaxes. Lighter winds will result in sub small craft
conditions Friday. SCA conditions are possible Saturday,
especially on the ocean. A strong N-NE flow develops Saturday
night behind a departing low pressure system leading to
widespread wind gusts 25-30 kt. There is even potential for gale
gusts on the ocean. These conditions will likely persist into
Sunday.
-- End Changed Discussion --

&&

.HYDROLOGY...
-- Changed Discussion --
Total precipitation of less than a quarter inch through tonight
(mostly in the form of rain) will not present any hydrologic
issues.

1-2 inches of rain is possible late Friday night into Saturday
night. Minor flooding appears to be the main threat at this
time. Flash flood guidance has recovered some over the past week
and soil moisture has decreased a bit. There remains
uncertainty with the placement of the heaviest rainfall axis,
but current model consensus hints at Long Island and southern
Connecticut seeing the highest rainfall amounts. It is too early
to determine if any impacts to rivers/streams will occur with
this rainfall.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Gale Warning from 6 PM this evening to 10 AM EDT Thursday for
     ANZ331-332-335-340-345.
     Gale Warning from 6 PM this evening to 6 AM EDT Thursday for
     ANZ338.
     Small Craft Advisory until 6 PM EDT this evening for ANZ350-
     353-355.
     Gale Warning from 6 PM this evening to noon EDT Thursday for
     ANZ350-353-355.
-- End Changed Discussion --

&&

$$

SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...DBR
LONG TERM...DS
AVIATION...JC
MARINE...JM/DBR/DS
HYDROLOGY...JM/DS