Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 030248
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
948 PM EST Tue Mar 2 2021

.SYNOPSIS...
Strong high pressure to the west will weaken and slide to the
south tonight into Wednesday as a warm front passes well to the
north. A cold front will approach from the north Wednesday night
and pass through early Thursday. The region will then be situated
between strong low pressure over the Canadian Maritimes and high
pressure across southern Canada Thursday into Saturday. The high
pressure will build over the region early next week.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Forecast is on track. This update takes into account recent
observations and trends of temperatures, dew points, and winds
into the overnight period and early morning.

High pressure to the west slides off the Mid Atlantic coast
this evening. Winds should turn W to WSW and continue to
diminish through the night. After evening low temps in the
teens inland/Long Island Pine Barrens and in the 20s elsewhere,
temps should become steady or slowly rise overnight. Skies
should also become partly cloudy to mostly cloudy over southern
CT and possibly eastern Long Island as a warm front passes to
the north.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Wed should be a mostly sunny day, and with mixing to mixing to
875mb or so and downslope W winds 10-15 mph it should be a
noticeably milder day, with highs around 50 for NYC metro and
most of Long Island, and in the mid/upper 40s to the north. Was
tempted to go even warmer, but temps in first day of return flow
often stay on the medium to low side of the guidance envelope.

A dry cold fropa expected toward morning Thu, with winds
shifting NW and low temps from 30-35 NYC metro to 25-30
elsewhere.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
A deep closed low aloft over the Canadian Maritimes will slowly
retrograde a bit westward on Thursday. This upper low is then likely
to meander over the Canadian Maritimes Friday into the weekend
carving out mean troughing over the northeastern seaboard through
the weekend. Upper ridging will persist across the Rockies into
Central Canada late this week before gradually shifting eastward
this weekend and early next week. The mean trough axis on the
ensembles is too far east for any system to impact the region and
the overall synoptic pattern favors dry conditions in the long term.
Temperatures will generally average below normal into the weekend.
Temperatures then trend towards above normal levels early next week
as the mean trough shifts offshore and the upper ridge builds over
the eastern states.

A cold front moves further offshore Thursday morning with cold
advection taking shape through the day. A breezy NW flow will also
occur due to the increasing pressure gradient over the area between
building high pressure to our west and the aforementioned low
pressure across southeast Canada. The breezy NW flow will continue
Thursday night into Friday before gradually diminishing this weekend
as the high pressure slowly nears and the pressure gradient relaxes.
The high should then build to our south early next week.

The models continue to indicate a southern stream shortwave
traversing across the Gulf Coast Friday into the weekend, then
interacting with a northern stream shortwave within the mean upper
trough. Due to the aforementioned positioning of the mean trough,
the low pressure associated with these systems is expected to pass
well south and east of the northeast coast. Have removed the slight
chance PoPs from the forecast on Sunday.

Temperatures on Thursday will be close to normal in the lower to
middle 40s, then middle to upper 30s on Friday. Some slight
moderation is possible this weekend with highs in the upper 30s to
near 40 degrees. Temps should then warm back into the 40s Monday and
possibly into the lower 50s by next Tuesday. Nighttime temperatures
will generally be in the 20s through the weekend.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR as strong low pressure remains in the Canadian Maritimes
through the overnight, a warm front passes well north, and high
pressure to the west shifts to the south tonight, then weakens
on Wednesday.

Widespread gusty winds have diminished with NW flow becoming
more W overnight. Winds then shift to SW late tonight,
generally under 10 kt, and become W-NW 10-15 kt Wednesday
morning. There may be occasional gusts to near 20 kt by late
Wednesday morning.

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

The occurrence and timing of any gusts on Wednesday may be off
by an hour or two.

.OUTLOOK FOR 03Z THURSDAY THROUGH SUNDAY...
.Wednesday night through Sunday...VFR. NW winds G20-25 on Thu, and
G25-30kt on Friday.

Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90

&&

.MARINE...
Low water advisory continues for tonight for all but eastern
CT/Long Island, as water levels around times of low tide likely
bottom out at a little over 2 ft below MLLW.

The gale warning on the eastern waters has been converted to an
SCA. Most waters will then see SCA conditions through tonight
although there may be a slight weakening overnight before winds
ramp back up again early Wednesday morning through the
afternoon. Winds on the Western LI Sound and NY Harbor should
gradually weaken below SCA levels this evening. There may be
occasional gusts up to 25 kt Wednesday morning, but for now have
held off on any SCA for this time frame. Ocean seas will remain
elevated through Wednesday and some 5-ft seas could linger into
Wed night on the outer ocean waters E of Moriches.

SCA conditions are likely on the waters from late day Thursday
through Friday night due a tight pressure gradient. The pressure
gradient begins to relax by Saturday morning with winds likely to
fall below SCA levels on all waters for the upcoming weekend.
The strongest winds are likely to occur Thursday night into Friday
and ocean wind gusts may reach around 30 kt. Ocean seas will build
to around 5 ft Thursday and remain there through Friday before
subsiding Friday night.

&&

.HYDROLOGY...
No hydrologic impacts through the weekend.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 1 PM EST Wednesday for ANZ330-340-
     345-355.
     Small Craft Advisory until 7 PM EST Wednesday for ANZ350-353.

&&

$$
SYNOPSIS...BG/DS
NEAR TERM...BG/DS/MW
SHORT TERM...BG
LONG TERM...DS
AVIATION...MW
MARINE...BG/DS
HYDROLOGY...BG/DS


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