Area Forecast Discussion
Issued by NWS Upton, NY

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953
FXUS61 KOKX 152033
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
433 PM EDT Thu Aug 15 2024

.SYNOPSIS...
Weak high pressure remains in place through Friday night. A
frontal system approaches the region from the Great Lakes this
weekend with its central low eventually moving across early
Monday. The low may linger nearby thereafter through early
Tuesday before high pressure moves in for mid to late next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A mid-level low embedded in a trough positioned over the Canadian
Maritimes continues to spin, allowing for spokes of energy to move
over portions of coastal New England this afternoon. This is
allowing for the development of isolated to scattered showers and
thunderstorms to the north. These showers and storms may gradually
move south and make their way closer to the coast into the evening,
but with little to no shear, these showers and storms will struggle
to maintain themselves for longer than an hour or so. A relatively
dry sub-cloud boundary layer may allow for locally gusty winds as
any storms collapse. While not likely, small hail will also be
possible in the strongest of storms, mainly for northern portions of
the CWA in Connecticut.

Otherwise, weak surface high pressure continues to remain in place
through the night with skies becoming clear to mostly clear and
winds becoming light and variable tonight. Some radiational cooling
may take place in the outlying and interior areas with lows possibly
dropping into the low 60s. Most other areas will see lows in the
upper 60s to near 70 in the NYC metro. Cooler spots may allow for
the development of patchy fog.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Upper level ridging moves overhead into Friday allowing for mostly
dry conditions during the day. Mostly sunny skies during the morning
and early afternoon will become at least partly cloudy by evening
with the approach of the next frontal system to the west. Winds will
be light and variable with high pressure sliding offshore,
eventually becoming primarily south by the afternoon and evening.
This will allow a subtle advection of moisture back into the region
along with continued increased cloud cover. High temperatures on
Friday will be in the middle to upper 80s for much of the area. Some
spots near the NYC metro may rise into the low 90s.

The increase in moisture and cloud cover by Friday evening will
prevent low temperatures from dropping much Friday night. Lows will
be in the middle 60s to near 70 for much of the area. As the frontal
system approaches from the west overnight, some scattered light
showers may approach the western portions of the area by morning on
Saturday, but these look to be widely scattered and confined to the
extreme western CWA.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
A strong upper level trough approaches the region this weekend. The
associated upper level axis is forecast to be just west of the
region Monday with an eventual progression of this axis to move
across the local region early Tuesday. The trough pattern lingers
near the region going through the middle of next week but forecasts
exhibit consistent weakening with rising mid level heights.

At the surface, a frontal system approaches. The warm front
approaches Saturday into Saturday night. It moves across Sunday. The
central low move in along with the cold front by early Monday.

Showers and thunderstorms will be in the forecast, higher
probabilities Saturday night through Monday. Drier trends Tuesday
into Thursday next week as high pressure returns.

Temperatures are forecast to not deviate too much from normal for
much of the long term period.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
Weak high pressure generally remains in control through the TAF
period. VFR forecast.

Mainly a light N/NW flow this afternoon, though sea breezes
turn coastal terminals southerly or southwesterly by late
afternoon, before becoming light and vrb tonight with high
pressure settling overhead. Flow becomes southerly Friday
afternoon as the high shifts offshore. Speeds remain at or under
10 kt.

A few scattered showers or thunderstorms are possible this afternoon
and early evening, generally through about 00Z, with the best
chance of seeing this at inland and CT terminals, KSWF, KHPN,
KBDR, and KGON. Brief category declines possible with any
heavier shower or a thunderstorm. Though this is also possible
at NYC and LI terminals, coverage is expected to be more
isolated closer to the coast and have left out of TAF at this
time. Any activity dissipates in the early evening, and skies
clear overnight into Friday morning.

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

AMD possible this evening for timing of sea breeze.

Low potential for showers and thunderstorms this afternoon.

OUTLOOK FOR 20Z Friday THROUGH TUESDAY...

Friday: VFR.

Saturday and Sunday: Showers likely with chance of tstms, especially
in the afternoon/early evening, and especially from the NYC metros
north and west. MVFR or lower conditions possible.

Monday: Mainly VFR. MVFR or lower possible in any SHRA/TSRA in the
afternoon.

Tuesday: Becoming VFR. MVFR or lower possible in any SHRA/TSRA
in the afternoon....mainly eastern terminals

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

&&

.MARINE...
Weak high pressure over the area is allowing for a weak pressure
gradient and light flow. This is allowing for sub-SCA conditions on
all waters through Friday. Waves begin to increase Friday night and
into the weekend with energy from distant Hurricane Ernesto reaching
the coast. Waves will largely be 5-7 feet Friday night through the
weekend. Small Craft Advisories are in effect for all the ocean
zones beginning Friday evening.

SCA conditions likely for the ocean this weekend through early next
week. The ocean could potentially return to below SCA conditions
Tuesday night. The SCA potential will be due to mainly elevated seas
as they build in response to Tropical Cyclone Ernesto passing well
offshore in the Atlantic. Please refer to the National Hurricane
Center regarding the latest details and track regarding Ernesto.

Winds are forecast to stay below SCA thresholds this weekend through
Tuesday night of next week. Non-ocean waters are also forecast to
remain below SCA thresholds during this timeframe.

&&

.HYDROLOGY...
No impacts expected with the isolated to scattered
shower/thunderstorm activity into this evening. There will be
potential for heavy rain especially with thunderstorms this
weekend and into Monday of next week. The higher likelihood of
rain starts Saturday night and continues through the rest of the
weekend. Total amounts of rain during this timeframe are
forecast to be up to near a quarter to half inch for much of the
area. There will likely be locally higher amounts. This will be
tied with the frontal system moving into the area.

There will be a chance for minor flooding in poor drainage,
urban, and low lying areas for the entire forecast region. There
is a marginal risk for much of the area for flash flooding. The
probabilities and associated confidence are too low at the
moment to specify specific spatial areas or time windows for
higher chances of flooding.

&&

.TIDES/COASTAL FLOODING...
The rip current risk is moderate this afternoon, and will
continue to increase into Friday, reaching a high risk Friday
afternoon and likely remaining that way through the upcoming
weekend. The increasing rip current risk is due to increasing
incoming SE to S long period swells from Hurricane Ernesto.
Please refer to NHC for official forecasts regarding Hurricane
Ernesto.

Minor coastal flooding may be possible early next week during high
tide cycles Sunday through Tuesday as swells build and astronomical
tides increase due to the full moon on Monday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 10 PM Friday to 6 PM EDT Saturday
     for ANZ350-353-355.

&&

$$

SYNOPSIS...JM/MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...JM
AVIATION...BC/IRD
MARINE...JM/MW
HYDROLOGY...JM/MW
TIDES/COASTAL FLOODING...