Area Forecast Discussion
Issued by NWS Upton, NY

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975
FXUS61 KOKX 090827
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
427 AM EDT Thu May 9 2024

.SYNOPSIS...
Multiple low pressure systems form southwest of the area today and
track nearby to the south tonight through Friday night. A series
of lows move through the vicinity of the region this weekend.
High pressure builds offshore for early next week before another
low potentially moves in for the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
The area will have the northern edge of high clouds streaking across
this morning, before mid level clouds arrive during this afternoon.
The pressure gradient will be quite weak, thus the winds will be
light throughout the day and generally 5 mph or less. Multiple low
pressure centers from across the Ohio Valley during the first half
of today, before getting into the Central Appalachians later today
and this evening. This will bring more in the way of clouds towards
late this afternoon and this evening. Have pushed back the timing of
the higher coverage / percentage of rain / showers for today. A good
percentage of the day will be completely dry. This will change
however towards the late day and evening.  Temperatures will be
close to normal with mainly upper 60s to lower 70s.

During this evening the column will gradually moisten. Showers
should break out for all areas at some point during the evening. The
low level flow will start to become onshore and out of the ENE. This
should lead to a stratiform rain / shower activity, although there
is some hint of a small amount of CAPE / instability in BUFKIT
soundings. Much of the time the rain will be light, with perhaps a
couple of moderate pulses into Friday morning. Temperatures should
average closer to normal with lows in the upper 40s to lower
50s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
For Friday expect overcast skies with periods of light rain
continuing. The CAMs are in fairly good agreement on it being a damp
and unsettled day. There are differences among the various guidance
as to whether some steadier rain could develop for the afternoon as
suggested by some HRRR model runs. The winds will remain onshore out
of the ENE and this will keep temperatures below average with a wind
off the colder water and overcast skies. Temperatures therefore in
all likelihood will have difficulty getting out of the 50s.

For Friday night the last wave of low pressure gets a bit further to
the south and eventually offshore. This should lead to more of a NE
to N flow which should result in a little bit of low level drying.
Thus the guidance is indicating light rain or showers becoming more
intermittent and even ending before daybreak Saturday. Total
rainfall amounts will total up to a half inch or so for much of
the area, with lesser amounts further northeast. NW sections of
Orange County may receive up to 3/4 of an inch. Temperatures
should be near normal with middle 40s to around 50 for lows.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The upper level jet is shown to remain south of the region this
weekend and then with more ridging next week, parts of the upper
level jet traverse the local area.

Mid level trough south of region Saturday morning, then shifts east
during the day with brief ridging as the local area will be in
between shortwaves.

Next shortwave moves in Saturday night with another moving south of
the region Sunday. The larger trough encompassing these shortwaves
and periodic positive vort maxima will be lingering across the
region through Sunday. This trough then moves east of the region
Sunday night.

Overall, the larger scales convey a mid level ridging trend taking
place for early into middle of next week for the local area. For
Monday night into early Tuesday next week, a subtle small shortwave
embedded within the ridge is forecast to move across. Wednesday into
Wednesday night, the next trough could be potentially moving in from
the west, although the timing with the guidance varies with some not
bringing in the trough until Thursday

At the surface, low pressure moves south and eventually southeast of
the region Saturday. Weak pressure gradient follows across the local
region. This weak high pressure will be brief as low pressure
approaches Saturday night and moves near to south of the area early
Sunday. Low pressure passes southeast of the region Sunday into
Sunday night.

Offshore high pressure briefly builds in late Sunday night into
early Monday and then moves farther offshore as another wave of low
pressure approaches Monday afternoon into Monday night. This low
pressure will be weak and will traverse the local area late Monday
night into early Tuesday. Another low may approach the area next
Wednesday.

Chances of rain showers are forecast much of this weekend. Despite
cooler air aloft, cooler air will also be in place at the surface,
so there may not be as much instability on Sunday as previously
thought. Have removed chances for thunderstorms in favor of showers
on Sunday.

Mainly dry conditions are forecast Sunday night through Monday.
Then, the next chance of rain showers is forecast Monday night and
again Tuesday afternoon into the midweek timeframe, depending on how
and when the trough sets up and traverses the region.

Temperatures for the weekend exhibit less of a diurnal trend, and
generally expected to be below normal for daytime hours and then
near to above normal for next week.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A cold front has passed through and is now departing to our
south where it is expected to stall through the mid Atlantic
region. A wave of low pressure tracks along the stalled boundary
late Thursday afternoon into Thursday night.

VFR. At KGON there is a chance of IFR conditions until around
12Z with fog and stratus. Then late in the forecast, toward
00Z, there is a chance of showers, with MVFR occurring a few
hours after the rains arrival, then dropping to IFR a few hours
after that.

Winds are light and variable in some areas with others between
5-10kts from the NW-NNW. Winds turn almost due north a few
hours after daybreak 5-10kts. Winds shift in the afternoon
becoming southeasterly with the sea breeze around 18-21Z with
gusts up to 20kt possible in the evening and night. Amendments
may be needed for sea breeze timing.


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

A sea breeze in the afternoon may require amendments to adjust
for timing.

Timing of the rain`s arrival and lowering of ceilings may
be off by a couple of hours.

OUTLOOK FOR 09Z FRIDAY THROUGH MONDAY...

Friday: MVFR or lower with showers likely.

Saturday and Sunday: Chance of MVFR or lower in showers.

Monday: Mainly VFR. Isolated showers possible at KSWF.

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

&&

.MARINE...
A weak pressure gradient will lead to light winds for much of today,
before a E to ENE wind gets established tonight. Sub small craft
conditions will prevail through today with 2 ft ocean seas. By
tonight the ENE flow should increase enough on the north side of a
front down to the south. Small craft wind gusts develop on the ocean
and NY Harbor with more marginal small craft gusts which may be more
occasional for the remaining non-ocean waters for tonight. By Friday
the winds should very slowly decrease as the winds gradually back
more to the NE and N into Friday night. Thus, prevailing sub small
craft conditions likely to resume by late Friday afternoon. For the
long term period of Saturday through Monday night, SCA conditions
are unlikely for winds with waves on the ocean remaining around 3
feet, occasionally 4 feet.

&&

.HYDROLOGY...
There are no hydrologic concerns throughout the forecast period.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides run high the next couple of days with the
new moon from earlier this week.

Another round of minor flooding, with localized moderate
flooding is possible for the Thu and Fri evening high tides in
the most vulnerable spots of southern Nassau, with advisories
and statements likely in similar locations, and perhaps
including SW and SE Suffolk and portions of the north shore of
Long Island in subsequent evening high tide cycles through
Friday. Statements may also be needed for Thursday and Friday
evening for portions of coastal NE NJ and Staten Island.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from midnight tonight to 2 PM EDT Friday
     for ANZ338-350-353-355.

&&

$$

SYNOPSIS...JE/BR
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...BR
AVIATION...BR
MARINE...JE/BR
HYDROLOGY...JE/BR
TIDES/COASTAL FLOODING...