352
FXUS61 KOKX 121943
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
343 PM EDT Thu Sep 12 2024
.SYNOPSIS...
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High pressure continues to maintain control across the region
through this weekend and into Monday, then will weaken going
into midweek as it gradually moves more offshore. A frontal
system approaches from the west but looks to stay mostly to the
southwest of the region Wednesday into Thursday of next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Abundant sunshine continues through the remainder of the day with
high pressure centered just offshore of southern New England.
Onshore flow persists into tonight, pushing dew points along
the coast into the upper 50s and lower 60s. This plus
radiational cooling should lead to more widespread fog and low
stratus late tonight. Capped at patchy for now, but localized
dense fog is possible, especially in the valleys. Low
temperatures tonight range from the mid 50s inland and across a
good deal of eastern Long Island, to the lower 60s in the NYC
metro area.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
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Amplifying deep layer ridging over the Great Lakes translates
east across the region into the weekend while surface high
pressure remains centered just offshore.
No precipitation is expected in the period, but morning fog and
stratus possible each morning with the persistent, light onshore
flow. This burns off with heating and leads to abundant
sunshine both days, perhaps filtered through a bit of haze from
an elevated wildfire smoke plume passing through the Northeast.
Temperatures run several degrees above normal for mid September
as the ridge builds overhead. Highs on Friday top out within a
few degrees of 80, warmest across urban NE NJ. Saturday may be a
hair warmer, with low to mid 80s across the Tri-State. Overnight
lows bottom out in the 50s and 60s.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
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Overall, weather remains mainly dry with the exception of Wednesday
and Thursday of next week, when there could be some rain showers.
Confidence not high on this however, so have just slight chance POPs
for rain showers as there is more model uncertainty with the
forecast. Otherwise, temperatures look to remain mostly near normal
as the airmass will not exhibit significant changes.
Each late night into the early morning, there will be potential for
fog formation especially outside of NYC. Have mentioned patchy fog
for much of the region outside of NYC for early Sunday morning as
well as for late Sunday night into early Monday morning. The same
cyclical fog formation and subsequent dissipation with diurnal
heating could very well occur for late night into morning of the
remainder of the forecast period.
Aloft, strong ridge over the region Sunday will linger into early
next week and then gradually shift offshore Tuesday into the middle
of next week. GFS and Canadian models are showing a trough
approaching the region for latter part of next week while the ECMWF
keeps a stronger ridge and a weaker approaching trough.
At the surface, high pressure continue to maintain control over the
weather across the region, keeping dry conditions Sunday through
early next week. By Wednesday and Thursday of next week, the
operational GFS and Canadian models are indicating more weakening of
pressure across the local region with high pressure farther out to
sea. These two models are conveying the approach of a frontal system
with some rain returning to the local region. The GFS model shows
less rain than the Canadian model for the local area. ECMWF
operational model keeps stronger high pressure closer to the area
and is much drier, keeping the area dry through next Thursday.
After noting a general increase across the area with regards to POPs
within the LREF, did slightly increase POPs spatially across the
region for Wednesday night through Thursday night. However, after
noting a shift to later in the week with the rainfall compared to
previous forecast, POPs remain in slight chance for showers. In
addition, the LREF 500mb height depiction and operational models do
not show too much of a decrease in the 500mb height, with the
operational Canadian models showing more of a negative anomaly with
respect to the LREF 500mb height percentile analysis, below the 25th
percentile. This leans the forecast to relatively less rain shower
chances, thereby keeping more continuity with the previous forecast
considering the increasing uncertainty for Tuesday through Thursday
of next week.
Temperatures throughout the long term are not forecast to deviate
much from normal values. High temperatures are generally in the
upper 70s to near 80 for most locations during the day. Lows for
late night into early morning are generally in the 50s and 60s. The
lows range from the mid 50s to low 60s Sunday night and Monday night
and then more in the upper 50s to upper 60s for Tuesday night and
Wednesday night of next week.-- End Changed Discussion --
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
High pressure remains centered to our east through Friday.
VFR for much of the period. There is a chance for IFR cigs/vsbys
from about 08Z to 13Z Friday. The combination of increasing
low-level moisture is forecast to allow for the development of
low clouds and fog late tonight. Best chance looks to be at the
coastal terminals and KHPN. Confidence is increasing, but will
continue to address the potential in a TEMPO group.
SE-S winds less than 10 kt this afternoon will once again
become light and variable tonight. Onshore flow will redevelop
on Friday from the S-SE. KLGA may stay from the NE into early
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
KLGA could hold on to NE winds 1-2 hours longer than currently
forecast.
MVFR/IFR potentially prevails for at least a few hours late
tonight into the Friday morning push - low to moderate
confidence.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday Afternoon-Tuesday: Mainly VFR, but a chance of MVFR or
lower fog/clouds for each late night/early morning.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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Conditions on the waters are forecast to remain below SCA thresholds
through early next week with an overall weak pressure gradient
in place. Wind gusts are expected to remain below 20 kt and the
maximum seas forecast on the ocean is 4 ft. The 4 ft ocean seas
are forecast to be mainly in the Monday through Tuesday night
timeframe.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic concerns through the middle of next week.
&&
.TIDES/COASTAL FLOODING...
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There is a moderate rip current risk at the NYC and Nassau
beaches today, with incoming E swell of 2 ft/9 sec and a S sea
breeze increasing close to around 10 kt. The moderate risk
continues there for Fri and includes SE Suffolk per RCMOS
guidance, with a similar wind regime and slightly higher
SE swell.
With an approaching full moon for next week on September 17th,
astronomical levels will be rising leading up to that date. With the
continuous easterly flow, this will help build seas and allow for
some piling of water. Winds are expected to remain generally light,
near 10 kt or less. Thinking there will be a possibility for some
tidal locations to be near or at minor coastal flood benchmarks as
indicated by some surge models Sunday into early next week. This
would be mainly for the South Shore Bays and Western Long Island
Sound shorelines and maybe a few locations along the NY Harbor.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JM
AVIATION...DW
MARINE...JM/DR
HYDROLOGY...JM/DR
TIDES/COASTAL FLOODING...