discussion on 2023-06-02

000
FXUS61 KOKX 021733
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
133 PM EDT Fri Jun 2 2023

.SYNOPSIS...
A cold front will start to approach from the north this
afternoon and evening, and then move through from the northeast
late tonight into Saturday morning. A high pressure ridge will
then develop along the coast Saturday into Saturday night and
linger into Monday. A cold front passes through Monday night.
Low pressure then lingers in the area Tuesday through Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Still leaning toward the CAM`s, however, adjusting timing and
areal coverage. Thunderstorms developing across the higher
elevations mainly N of the CWA and also in parts of Orange
County early this afternoon, with activity isolated at first,
then increasing somewhat in coverage during mid to late
afternoon as storms move S into inland sections of the CWA.
Development along the sea breeze front also possible in NE NJ.
Wind fields are weak so do not expect much organization to the
convection this afternoon, mainly pulse tstms. Stronger cells
are capable of producing small hail given sufficient -10C to
-30C CAPE as shown on NAM fcst soundings, also gusty winds via
steep low level lapse rates and relatively dry mid level/sub-
cloud air. Cannot entirely rule out an isold damaging wind gust
with the above parameters leading to DCAPE over 1000 J/kg and
WINDEX parameter over 50 kt in spots NW of NYC.

Main push of numerous showers and a few tstms should come from
late evening into the first half of the overnight as the back
door cold front moves into the area from the NE. The front
should be through most of if not all the CWA by daybreak Sat.

Additional showers are also possible late tonight into Sat AM
via lift from a mid level vort max at the trailing base of a
digging Canadian Maritimes upper trough. Low temps tonight will
range from the lower 50s across far ern CT, to the lower 60s in
NYC.-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Showers should come to an end Sat AM, with a high pressure ridge
developing along the coast and a gusty NE flow in place for the
daytime hrs. Temps Sat into Sat night will be below normal,
with highs only in the 60s, then falling to the lower 50s in NYC
and into the 40s elsewhere.

Offshore low pressure developing E of New England may throw some
clouds and a few showers back into the area Sunday into Sunday
night, mainly across SE CT and ern Long Island. Highs on Sunday
should reach the lower 70s from NYC north/west, with 60s to the
east. Low Sunday night should range from the mid 50s in NYC, to
the lower 50s in the rest of the metro area and along most of
the coast, to the 40s inland.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Weak high pressure will be over the area for Monday as we`ll be
between an area of low pressure offshore and another low
pressure center shifting SE from southern Quebec. Showers
possible, but low chances overall. A somewhat better chance of
showers for Monday night with the passage of a cold front.

Relatively weak surface low pressure with maybe a couple of
surface troughs then can be expected Tuesday through Thursday
as a longwave trough/closed 500mb low lingers across the
Northeast. A chance of showers through the entire period. With
the cold pool aloft and sufficient CAPE, instability and lapse
rates could promote some thunder each afternoon. Most the period
will be dry though - just a threat of a shower at any given
time.

High temperatures mostly in the lower and middle 70s for Tuesday
and Thursday. Wednesday will probably be a little cooler with
more in the way of clouds and a cooler boundary layer.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --A backdoor cold front approaches this afternoon and passes
through overnight. High pressure builds towards the region out
of southeast Canada on Saturday.

VFR through this afternoon. There is a chance for showers and
thunderstorms, mainly inland across Lower Hudson Valley and
Connecticut. The probability of thunderstorms increases towards
00z and continues into the first half of the night closer to the
coast. The chance for thunder diminishes after 03/04z, but
showers remain likely into the early morning hours. Brief MVFR
is possible in heavier downpours.

MVFR ceilings should become widespread from north to south
after 06z. IFR becomes likely early Saturday morning,
transitioning to MVFR by middle morning and then VFR in the
afternoon.

S-SE flow around 10 kt this afternoon with some inland terminals
remaining NE. Winds should start backing towards the ESE-E this
evening, becoming variable the first half of tonight. Winds will
become NE and increase early Saturday morning once the backdoor
front moves south of the area. Sustained NE winds around 15 kt
with gusts 20-25 kt likely on Saturday.

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

Isolated showers possible this afternoon.

Timing of thunderstorms may need to be adjusted this evening.

Winds at KLGA may stay NE a few hours longer this afternoon
before shifting to the SE.

OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday PM: Becoming VFR. Becoming VFR in the afternoon. NE
winds around 15kt with gusts around 25kt, highest at the coastal
terminals. Winds diminishing in the evening.

Sunday: Mostly VFR, a chance of MVFR with showers east of the
NYC metro terminals. NE wind gusts 15-20 kt possible.

Monday: VFR, a slight chance of showers.

Tuesday-Wednesday: Mainly VFR, a chance of mainly afternoon and
evening showers and thunderstorms with MVFR.

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

&&

.MARINE...
No changes to winds and seas, or hazards, at this time.

After a back door cold frontal passage late tonight, SCA conds
should develop from W to E late tonight into early Sat morning,
and persist into Sat night, with NE winds gusting to 30 if not
occasionally 35 kt on the ocean, and ocean seas building to 5-8
ft. Did not yet raise SCA for the wrn Sound and NY Harbor as any
gusts to 25 kt there could be more sporadic.

Ocean seas as high as 5 ft may linger on the outer ocean waters
from Sunday into at least Monday morning. Sub-SCA conditions are
otherwise expected for the remainder of the period.

&&

.HYDROLOGY...
No hydrologic impacts expected through early next week.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will be running relatively high this weekend as a
full moon occurs Saturday night. Combined with a moderate NE-ENE
wind flow, tidal piling with the help of Ekman transport will bring
a decent chance of widespread minor coastal flooding Saturday and
Sunday evenings across some of the area. Best chances appear to be
from the Nassau County south shore back bays westward into Southern
Queens/Brooklyn, most of NY Harbor, as well as Southern Fairfield
and Southern Westchester Counties. Minor flooding could be possible
across the back bays of southern Suffolk County as well as along
Peconic and Gardiners bays. Localized moderate flooding may occur
both nights in southern Nassau County. In most cases, only a half
foot to 1.5 feet of tidal departure will be needed to reach minor
flooding.

A moderate rip current risk is expected today and Saturday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 11 PM EDT Saturday for
     ANZ331-340.
     Small Craft Advisory from 3 AM to 11 PM EDT Saturday for
     ANZ332.
     Small Craft Advisory from 3 AM Saturday to 6 AM EDT Sunday for
     ANZ350.
     Small Craft Advisory from 6 AM Saturday to 6 AM EDT Sunday for
     ANZ353-355.

&&

$$
SYNOPSIS...BG
NEAR TERM...BG/MET
SHORT TERM...BG
LONG TERM...JC
AVIATION...DS
MARINE...JC/BG/MET
HYDROLOGY...JC/BG
TIDES/COASTAL FLOODING...