000
FXUS61 KOKX 031123
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
723 AM EDT Sun Sep 3 2023
.SYNOPSIS...
High pressure will generally be in control through the middle of
the week. A cold front should then slowly approach at the end of
the week and could linger into next Saturday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
For this update, hourly temperatures and dewpoints were
slightly adjusted to better match hourly trends.
On the heels of shortwave trough that dropped across the
Northeast this morning, a high amplitude upper level ridge
encompassing much of the country will expand eastward into the
area. This will result in a much warmer day for the forecast
area by as much as 10 degrees. Highs are forecast to get well
into the 80s with the exception of far eastern LI and coastal SE
CT, where it will be cooler due to the onshore flow. Much of
the NYC metro will top off around 90, with the warmest readings
across NE NJ. This is about 7 to 10 degrees above normal.
Humidity levels while higher than a day ago will result in heat
indices not much higher than the forecast highs. Thus, not
looking at any heat headlines at this time.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
The theme will change little during this time as the upper
level ridge builds slowly eastward. An upper low over the
western Atlantic will serve as block during this time, not
allowing the full brunt of the heat to get into the area. Still
though, readings will be well above normal with daytime highs in
the upper 80s to lower 90S, with the exception of eastern LI
and SE CT. Lows will generally be in the 60s, but lower 70s
across the NYC metro. Heat indices during this time will be
highest across the NYC metro up into the lower Hudson Valley
where heat indices will right around 95. There is the potential
for heat advisories to be issued across these areas but
confidence remains low at this time. A heat advisory is issued
for heat index values of 95 or greater for any length of time
occurring on two consecutive days, or 100 to 104 for any length
of time. The former fits this scenario best and even then it is
looking marginal. There is also some uncertainty with the dew
point forecast as it`s possible the low-levelS dry out a bit
more than forecast due to mixing from daytime heating.
The forecast looks to be dry with some intervals of mid and
high clouds possible late tonight and into Monday as weak
shortwaves round the upper trough and move across the area.
There is decent elevated instability across the interior Monday
afternoon/early evening. However, low-levels are capped but
there is some uncertainty whether there could be enough lift
aloft to generate a brief shower or thunderstorm. The area is
then strongly capped on Tuesday.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
No significant changes were made to the long term forecast.
A high amplitude and large subtropical ridge will remain over
the eastern states Tuesday night into Wednesday. The ridge
should start to weaken Thursday although there are differences
in the global models on how quickly this occurs. The GFS is the
quickest with the ECMWF and CMC keeping the ridge stronger over
the region Thursday. The ridging should then situates itself
offshore on Friday as a more well-defined northern stream
shortwave approaches from the west, establishing troughing over
the northeastern states into next Saturday. A cold front slowly
approaches during the end of the week and possibly lingers
nearby on Saturday.
High pressure over the western Atlantic will remain in control
on Wednesday and then give way to a pre-frontal trough Thursday
ahead of the aforementioned approaching cold front. A warm air
mass will continue to be in place on Wednesday. Highs should
reach the lower 90s in the normally warmer spots of the NYC
metro, NE NJ, Lower Hudson Valley and interior Southern
Connecticut. Onshore flow across Long Island and coastal
Connecticut should hold highs in the lower to middle 80s. Felt
the NBM deterministic dew points were too high on Wednesday and
went on the lower side of the guidance, especially away from the
the coast and afternoon sea breezes. The atmosphere is dry and
should allow dew points to mix out into the middle 60s yielding
max heat indices in the lower 90s in the warmest spots. A few
locations in NE NJ could briefly touch 95 for a heat index.
Temperatures begin to trend down a few degrees on Thursday and
the latest model consensus indicates highs in the upper 80s to
around 90 away from the immediate coast. Max heat indices top
out in the upper 80s and low 90s. The pre-frontal trough may be
enough of a focus to support a shower or thunderstorm late in
the day and in the evening, mainly inland. However, if the
ridging holds on aloft, these chances may be limited.
Chances for showers and thunderstorms increase on Friday as
the upper trough approaches along with the cold front. The
increasing clouds and stronger onshore flow help cap high
temperatures in the lower to middle 80s. The front lingering
nearby on Saturday supports continued chances for showers and
helps keep temperatures in the upper 70s to low 80s.-- End Changed Discussion --
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
VFR as high pressure remains offshore through the TAF period.
Winds this morning will become W to WNW for most terminals
except KJFK, KISP, KBDR and KGON where winds will likely stay
SW. Sea breezes are likely at these terminals late morning into
the afternoon. Wind speeds at all terminals should range from
around 8 to 12 kt. Winds weaken this evening and become light
and variable overnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of sea breeze at KJFK may be off by 1-2 hours. An early
evening (23-01z) sea breeze passage is possible at KLGA with an
even lower chance of occurrence at KEWR.
A 15-18 kt gust possible at KEWR this afternoon.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Monday-Wednesday: VFR.
Thursday: VFR. Low chance for an evening shower or
thunderstorm.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Seas will primarily remain at 3 to 4 ft on the ocean waters
today with a SW flow 10-15kt. Seas largely being contributed to
by a lingering E/SE swell around 10s. This could still cause
rough conditions around the inlets. Thereafter, with a weak
pressure gradient, as high pressure remains in control, winds
and seas will remain below advisory levels across all waters.
&&
.HYDROLOGY...
No hydrologic impacts are expected through next week.
&&
.TIDES/COASTAL FLOODING...
Long period SE swells of 3-4ft and 9-11s through the holiday weekend
will result in a moderate rip current risk. E to SE swell will
likely continue into the first half of the week, with a moderate rip
current risk possible.
&&
.CLIMATE...
Some daily record highs could be tied or broken over the next
couple of days. The record highs for these dates are below.
DAILY RECORD HIGH TEMPERATURES...
SEP 4 SEP 5
CENTRAL PARK...97 (1929)...94 (1985)
LAGUARDIA......93 (2018)...93 (1985)
JFK............93 (2018)...94 (1961)
ISLIP..........92 (2018)...90 (1985)
NEWARK.........95 (2018)...94 (1985)
BRIDGEPORT.....91 (1973)...91 (1961)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DS/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DS
AVIATION...DS
MARINE...DS/DW
HYDROLOGY...DS/DW
TIDES/COASTAL FLOODING...
CLIMATE...