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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 082057
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
357 PM EST Mon Mar 8 2021

.SYNOPSIS...
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A ridge of high pressure builds in through this evening. Then,
a warm front will move across tonight. A cold front will move
across Tuesday morning into early Tuesday afternoon. Strong high
pressure then builds in from the west Tuesday afternoon through
Tuesday night. High pressure shifts to the east on Wednesday as
a slow moving frontal system approaches the area. The front
slowly moves through the area Friday and Saturday before high
pressure takes hold on Sunday. Another frontal system looks to
approach from the west early next week.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Winds decrease going into this evening and before clouds
increase, optimal radiational cooling will lead to surface
temperatures dropping rapidly during the evening hours. Then,
clouds increase with a warm front passage and low level SW winds
will increase late tonight. Warmer arrives in the 950mb to
850mb layer late evening into overnight and the surface will
follow this tendency but at a slower rate. The warm layer in the
950 to 850mb layer is forecast to reach 4 to 5 degrees C,
easily allowing for the melting aloft and surface precipitation
type to either be rain or freezing rain.

Winds will have a large amount of westerly flow from lower to upper
levels, keeping conditions mainly dry with the warm frontal passage.
However, some forcing aloft with small area of positive vorticity
advection at 500mb along with some 700mb omega will present a
possibility for some sparse coverage of very light rain or very
light freezing rain depending on the surface temperature. Some
mesoscale models and a few SREF members also indicate light
precipitation across a few parts of the region late tonight into
early Tuesday. GFS and ECMWF 12Z runs indicate a few small 0.01 inch
areas of precip across parts of Southern Connecticut and Eastern
Long Island.

The national blend of models was used for forecast lows tonight and
the forecast hourly temperatures become steady going into overnight
and eventually rise going into early Tuesday morning.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
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Slight chance of some lingering light rain across parts of
Southeast Connecticut and Eastern Long Island between 6 and 8am
Tuesday.

After Tuesday 8-9am, expecting any precipitation to move south
of Long Island with otherwise dry conditions. A cold front will
move northwest to southeast across the region Tuesday morning
into early Tuesday afternoon. Initial cold air advection behind
the cold front will allow for an increase in vertical mixing
depth and gusty winds, likely peaking in the late morning before
low level winds decrease for Tuesday afternoon.

For the high temperatures forecast on Tuesday, used a blend of
mixing down from 900mb using NAM12 temperatures along with a
consensus of MOS and went one degree higher. The resulting forecast
highs are mainly in the mid 50s to near 60. These are
relatively higher towards the coastline where there will be more
downslope flow.

A strong area of high pressure builds in from the west Tuesday
afternoon into Tuesday night. Strong subsidence will provide for
mostly clear sky conditions and a further decrease in winds as
the overall pressure gradient decreases. Forecast lows convey a
more vast range as radiational cooling will be optimal. The
forecast lows range from the lower 20s for parts of the interior
and the Pine Barrens of Long Island to lower 40s for parts of
NYC.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
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High pressure positioned over the area begins to move offshore late
Wednesday and winds become primarily southerly. With clear skies,
and dry conditions, temperatures will rise into the middle and upper
50s for much of the area, about 5-10 degrees above average.

A low pressure system over the Upper Midwest and southern Canada
will allow the pressure gradient to tighten over the area with high
pressure remaining just offshore. This will allow for a strengthening
S/SW flow over much of the area with temperatures remaining above
average through much of the middle and end of the week. The S/SW
flow will bring in more moisture as well allowing for skies to be
partly to mostly cloudy at times. High temperatures on Thursday and
Friday will be in the upper 50s for Eastern LI and SE coastal CT
with the rest of the region rising into the middle and potentially
upper 60s during the afternoon each day. This will be anywhere from
10-15 degrees above average and a nice preview of Spring.

As the cold front approaches the area on Friday, a chance of rain
showers will be possible with a relatively moist and warm airmass
ahead of the front. There is some disagreement as to how far the
cold front can move through the area on Friday night and Saturday.
The GFS pushes the cold front completely through the area by
Saturday with a primarily NE flow and dry conditions. The CMC and
ECMWF both slow the front down and allow for another wave to ride
along the front and bring the potential for more rain during the day
on Saturday. As of now, slight chance PoPs are in place due to the
uncertainty. Either way, temperatures looks to drop back down to
seasonable, generally in the upper 40s and low 50s.

A strong high pressure system looks to move into the area on Sunday
and into the beginning of next week with the next frontal system
approaching the area sometime in the late Monday to Tuesday
timeframe.
-- End Changed Discussion --

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
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High pressure builds offshore, giving way to a weak frontal
system approaching from the west. The warm front moves through
the area tonight, followed by a cold front Tuesday morning.

Mainly VFR. Brief MVFR possible overnight in spotty light rain.

WNW winds 5-10 kt will back around to the SSW this evening,
then back around to the WNW at 10-15kt G15-20kt Tuesday morning.

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

Winds mainly left of 310 magnetic this afternoon. A few gusts
15-17kt.

.OUTLOOK FOR 21Z TUESDAY THROUGH SATURDAY...
.Tuesday Afternoon...VFR. NW G15-20kt in the afternoon.
.Wednesday...VFR.
.Wednesday Night...MVFR or lower in stratus possible for coastal
terminals.
.Thursday...MVFR or lower AM coastal terminals, then VFR. S-SW
gusts 15-20 kt.
.Friday...Mainly VFR. Chance of showers. S-SW gusts 20-25 kt,
becoming W-NW late afternoon/evening.
.Saturday...Mainly VFR. Low Chance of AM showers. NW G15-20kt.

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

&&

.MARINE...
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Small craft advisory in effect from 07Z Tuesday until 18Z Tuesday
for the ocean east of Fire Island Inlet out 20 nm.

Conditions on the waters will be initially below SCA criteria
going into this evening. Then, after a warm front passage and ahead
of a cold front, SW winds will be increasing and the boundary layer
will increasing as well. This will be enough for gusts of 20-25 kt
to develop mainly on the ocean east of Fire Island Inlet. Other
waters will stay below that SCA wind gust threshold of 25 kt. The
gusts near 25 kt on the ocean east of Fire Island Inlet continue
into Tuesday before all waters are below SCA thresholds after 18Z.
Tranquil conditions expected for Tuesday afternoon into Tuesday
night with conditions getting well below SCA thresholds. Any
remaining wind gusts diminish Tuesday night. OCean seas are forecast
to be mainly 2 ft for Tuesday night.

Sub-SCA conditions on all waters on Wednesday and Wednesday night
with high pressure overhead.

Increasing S/SW flow on Thursday will bring SCA conditions on the
ocean waters with gusts 25-30kts and waves 5-7ft. Gusts for non-
ocean waters look to remain just below SCA Thursday and into Friday.
SCA conditions on the ocean continue through much of the end of the
week and into the weekend with conditions dropping below SCA by
Saturday afternoon. Gusts remain marginal for the ocean through the
beginning of next week. Ocean seas looks to build again near SCA
criteria Sunday afternoon.
-- End Changed Discussion --

&&

.FIRE WEATHER...
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There has been mainly dry conditions going back to late last
week. The forecast for Tuesday has forecast low level relative
humidity of around 30 to 35 percent and gusts up to near 20 mph.
These are almost conducive for enhanced spread of any brush
fires if any were to occur. With these limiting factors plus
some residual snow cover across parts of the interior, held off
on any special weather statement issuance for the time being.
The potential for any enhanced spread of any brush fires would
increase if dewpoints trend lower than forecast Tuesday or if
gusts increase closer to 25 mph or greater.
-- End Changed Discussion --

&&

.HYDROLOGY...
No hydrologic concerns are expected.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 2 AM to 1 PM EST Tuesday for ANZ350-
     353.
-- End Changed Discussion --

&&

$$

SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MW
AVIATION...DW
MARINE...JM/MW
FIRE WEATHER...
HYDROLOGY...JM/MW