000
FXUS61 KOKX 032354
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
754 PM EDT Sun Sep 3 2023
.SYNOPSIS...
High pressure remains in control through midweek then begins to
weaken Thursday as a cold front slowly approaches from the west
through Friday. The front moves through the region Friday night
through Saturday, possibly into early Sunday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Updated for current conditions.
Remaining dry and mild this evening and through tonight with
high pressure in place to our south and a building ridge to the
west.
Some high and mid level clouds may begin to work in overnight
with a weak shortwave in the flow, but sufficient dry air should
preclude any wet weather. Lows range from the mid 60s to low
70s in the urban metro, or about 5 degrees above normal for
early September.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
-- Changed Discussion --
After a cooler than typical August, a bit of late season heat
builds across the region early this week. An anomalous upper
level ridge amplifies over the Great Lakes on Labor Day, with an
upper low over the western Atlantic helping to impede its
progress east, leaving the region on the periphery. By Tuesday,
the ridge is able to advance overhead, maintaining dry, but hot,
conditions.
BUFKIT soundings prog 850 mb temperatures around 20C on Monday,
and with a well-mixed BL, surface temperatures should climb
into the high 80s and low 90s in the afternoon for most, or
about 10 degrees above normal. Surface high pressure centered
over the Southeast provides a light westerly flow, except where
coastal sea breezes develop and back winds southerly in the
afternoon. An upper disturbance rounding the ridge will allow
for some mid and high level clouds during the day, but
precipitation is not expected. It remains mild overnight into
Tuesday, with the metro only falling into the mid 70s.
The ridge slides overhead Tuesday, with similar, if not a
smidge warmer, conditions expected. Continued deep mixing likely
allows dew pts to fall below NBM both days as often the case.
Blended in the 10th percentile as a compromise, yielding low to
mid 60s during the day. Its possible the low-levels dry out a
bit more than forecast, and this is the challenge as it comes to
heat headlines.
Local heat advisory criteria is achieved when heat index values
of 95 degrees or greater are recorded for any length of time on
two consecutive days, or 100 to 104 for any length of time.
Given this, a Heat Advisory was hoisted for NE NJ zones, with
the exception of western Passaic, where confidence is highest in
heat indices reaching the mid 90s both Monday and Tuesday. For
NYC the lower Hudson Valley, and parts of southern CT, this
remains possible in some locales, but confidence in coverage on
Monday is not sufficient to include in the advisory at this
time. This could be expanded further should marginally warmer
conditions develop, and it should be noted the heat continues
into midweek. While widespread record heat is not anticipated, a
few sites may tie or break daily records either Monday or
Tuesday. See the Climate section below for further detail.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
The long term forecast remains fairly consistent with the
previous forecast.
A high amplitude and large subtropical ridge will remain over
the eastern states Tuesday night into Wednesday. The ridge
should begin to weaken and translate slowly eastward Thursday.
Meanwhile, a closed, and nearly cutoff, low over the
northwestern Atlantic remains south of Nova Scotia and drifts
east Thursday into Friday as a northern stream shortwave
approaches to the west. The high amplitude ridge will keep the
shortwave to the west of the region until Saturday as a near
Omega blocking pattern sets up.
A warm and humid airmass will remain along the eastern states
Wednesday into Friday, with temperatures Wednesday and Thursday
reaching the upper 80s along the coast, and into the lower 90s,
and possibly the mid 90s, inland, nearly 10 degrees above
normal. Overnight lows will generally be 5 to near 10 degrees
above normal. While the airmass remains in place Friday ahead of
a cold front, and with a thermal ridge across the area, with
850mb temperatures 19C to 20C, increased cloud cover and a
chance of precipitation will keep temperatures in the 80s. With
deep mixing Wednesday and Thursday dew points may mix out into
the mid 60s. Currently, heat indices are forecast to reach the
mid 90s across northeastern New Jersey, portions of the lower
Hudson Valley, and into Southwestern Connecticut Wednesday and
Thursday. However, if dew points lower a could of degrees during
peak heating maximum heat indices will fall short of the mid
90s. And Friday may feel more humid as little mixing is expected
with dew points possibly topping out around 70 to the lower
70s.
Chances for showers and thunderstorms increase Friday into
Saturday as the upper blocking patter slowly weakens allowing
the upper ridge to move into the western Atlantic and the
surface frontal system to track slowly eastward. There is some
timing uncertainty as to how quickly the blocking and upper
ridge weaken, allowing the upper shortwave to track through the
region. Some guidance is slower, and showers and thunderstorms
may linger into the beginning of Sunday.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Offshore high pressure will remain through the TAF period.
VFR conditions are expected to continue through the TAF period.
Tonight into Monday morning, winds will be near 5 kts or less with
variable wind direction but generally NW to N for NYC
terminals. KLGA could have more variable wind direction Monday.
Overall expect all terminals except for KSWF to develop a sea
breeze Monday afternoon into early Monday evening with CT
terminals likely developing the sea breeze late Monday morning.
KSWF develops a WNW flow Monday. Wind speeds Monday will
generally be near 7-10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Sound breeze potential for KLGA Monday morning into Monday
afternoon before ocean sea breeze moves in.
Timing of southerly sea breeze could be 1-3 hours off from
forecast.
KJFK wind speeds could be a few kts higher than forecast
especially Monday afternoon.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
Monday night-Wednesday: VFR.
Thursday: Mainly VFR. Low chance for a late afternoon into
evening shower or thunderstorm.
Friday: MVFR possible at times. Chance for showers and
thunderstorms.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Ocean seas remain 3 to 4 ft through Labor Day, with a lingering
SE swell around 10s. High pressure remains in control through
Wednesday, and begins to weaken Thursday as a frontal system
approaches from the west. The frontal system moves slowly
through the region Friday into Saturday. Winds and seas will
remain below SCA levels across the forecast waters Tuesday night
through Friday night.
&&
.HYDROLOGY...
No hydrologic impacts are expected through next week.
&&
.TIDES/COASTAL FLOODING...
Long period ESE swells of 3-4ft and 9-11s continue through Tuesday,
with a moderate rip current risk at the ocean beaches. Swells begin
to diminish late Tuesday into Wednesday.
&&
.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...Heat Advisory from 11 AM Monday to 8 PM EDT Tuesday for NJZ004-
006-103>108.
MARINE...None.
&&
$$
SYNOPSIS...DR/MET
NEAR TERM...DR/MET
SHORT TERM...DR
LONG TERM...MET
AVIATION...JM
MARINE...DR/MET
HYDROLOGY...DR/MET
TIDES/COASTAL FLOODING...
CLIMATE...