000
FXUS61 KOKX 041956
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
356 PM EDT Mon Sep 4 2023
.SYNOPSIS...
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High pressure remains in control through midweek. High pressure
begins to weaken Wednesday night into Thursday as a cold front
slowly approaches from the west through Friday. The front moves
into the region Friday night into Saturday, lingering nearby into
Sunday as waves of low pressure move along the front. High
pressure builds to the north Monday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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A high amplitude upper level ridge east of the Mississippi
River Valley and a blocking upper low over the western Atlantic
will allow for an unusually warm airmass to settle across the
region for the first half of the week. 85H temps increased to
around 18C today and will remain or slightly increase through
mid week.
A weak shortwave approaches this evening. There is the potential for
another round of showers and embedded thunderstorms across the Lower
Hudson Valley south and west. We remain capped for most of the
evening, however, there is about 3000 J/kg of MUCAPE available.
Although the latest CAMs show little to no activity, thinking there
is at least a slight chance of thunderstorms and have added this to
the forecast. This will largely depend on how strong the lift is
from the approaching shortwave.
Lows tonight will be about 10 degrees above normal, upper 60s
to mid 70s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
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Not much change during this period as the upper level ridge
translates a bit father east, but once again being blocked by an
upper low offshore. Above normal heat will continue through
Wednesday.
A Heat Advisory remains in effect for all of northeast
NJ, except western Passaic, through Wednesday. The Heat Advisory has
been expanded to include NYC and portions of the Lower Hudson
Valley. Confidence is highest in these areas that a heat index of 95
will be met at anytime during each of the two days over much of
the forecast zone. Isolated heat index values of 95 may be
reached across other areas of the Lower Hudson Valley and in CT,
but they will not be widespread. The biggest uncertainty
remains across CT with high cloud cover moving in for at least
the first half of Tuesday. This will have to continue to be
monitored.
This period will remain dry and mostly sunny for most. Lows remain
above normal.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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A high amplitude and large subtropical ridge over the eastern states
begins to weaken and translate slowly eastward Wednesday night and
Thursday. Meanwhile, a closed, and nearly cutoff, low over the
northwestern Atlantic remains south of Nova Scotia and drifts east
and north Thursday into Friday as a northern stream shortwave
approaches from the west and the upper ridge moves into the western
Atlantic. The high amplitude ridge increases over the western
Atlantic Friday and Friday night and remains into Sunday. This will
establish a nearly blocking Omega pattern, and keep the shortwave
and surface low to the west, or moves slowly eastward through the
upcoming weekend. Until then heat and humidity will remain across
the region Thursday, with temperatures once again reaching the lower
90s, possibly mid 90s, inland, and upper 80s to near 90 across the
coastal areas.
And with dew points remaining around 70 heat indices reach the mid
to upper 90s. However, there is some uncertainty, as clouds will be
increasing and there will be a chance of showers and thunderstorms
Thursday afternoon. But with the latest trends with the ridge
remaining and keeping the shortwave to the west, the onset of
precipitation may be delayed. The warm and humid airmass remains
into Friday, however 850mb temperatures are a couple of degrees
cooler than previous forecasts, and chances of precipitation remain.
With the slow moving upper shortwave and waves of low pressure
moving along the cold front, and precipitable water values mainly
1.50 to 1.75 inches, periods of moderate to heavy rain will be
possible. The front at this time moves east Sunday with high pressure
beginning to build to the north Monday.-- End Changed Discussion --
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
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High pressure will remain offshore through the TAF period.
Another area of showers is possible this evening across the Lower
Hudson Valley which heads south over the metro terminals. VCSH for
TAFs through 03Z, but thinking is it will likely end sooner than
what is in the TAFs. Overall coverage will be rather isolated, but
some of these may have an embedded thunderstorm that moves through.
If so, it will be associated with MVFR or lower conditions for a
brief time. This will mainly affect all terminals except KISP, KGON,
and KBDR.
Otherwise, mainly VFR conditions are expected through the TAF
period. However, an area of fog and low stratus may move in from the
east overnight tonight, and there is a chance that eastern terminals
may see some MVFR conditions or lower late tonight - around daybreak
Tuesday.
It now appears that the sea breeze will only make it through KJFK,
KISP, KBDR, and KGON. It is less certain with all other terminals
likely due to the clouds and showers keeping temperatures down, as
well as the trough that is causing these showers to develop
remaining in the vicinity, causing more of a NW to NE flow to
continue. Furthermore, the sea breeze may move back south and turn
the winds at KJFK and KISP to more of a W or NW direction late this
afternoon into the early evening. Winds become light and variable
overnight, with a light NW flow developing once again Tuesday
morning. Sea breeze is expected Tuesday, but there is uncertainty in
timing right now. Going with mid-morning for KJFK and late afternoon
for KLGA, KEWR, and KTEB.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low confidence of shower/thunder timing late this afternoon/evening.
Low chance that sea breeze moves through KLGA, KEWR, and KTEB. It is
possible the sea breeze moves back south of KJFK late this
afternoon/evening, before becoming light and variable.
OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday-Wednesday night: VFR.
Thursday: Mainly VFR. Low chance for a late afternoon into evening
shower or thunderstorm.
Friday through Saturday: 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...
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Ocean seas generally remain around 3 ft through mid week, however,
an ESE swell from offshore low pressure nearing the Canadian
Maritimes could increase seas to around 4 ft late
tonight into Tuesday.
High pressure begins to weaken Wednesday night into Thursday as a
frontal system approaches from the west. The frontal system moves
slowly through the region Friday into Sunday. Despite a persistent
southerly flow ahead of the frontal system, winds and seas are
forecast to remain below SCA levels at this time.-- End Changed Discussion --
&&
.HYDROLOGY...
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No hydrologic impacts are expected through Thursday.
A significant rainfall of 1/2 to 1 inch, with locally higher amounts,
is possible late Friday through Saturday as a frontal boundary moves
slowly through the region. There is still too much uncertainty with
the timing and areal extent of the rainfall.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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Long period ESE swells of around 3ft and 9-11s continue through
Tuesday, with a moderate rip current risk at the ocean beaches.
While these swells begin to diminish on Wednesday, a moderate risk
remains for the Nassau and Suffolk beaches, with a low risk at the
New York City beaches.-- End Changed Discussion --
&&
.CLIMATE...
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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 5 Sep 6 Sep 7
Central Park..94 (1985)..97 (1881)..101(1881)
LaGuardia.....93 (1985)..96 (2018)..90 (2015)
JFK...........94 (1961)..92 (1985)..93 (1983)
Islip.........90 (1985)..90 (1985)..92 (1998)
Newark........94 (1985)..98 (2018)..95 (2015)
Bridgeport....91 (1961)..92 (2018)..91 (1983)-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for
NYZ067-069-071>075-176-178.
NJ...Heat Advisory until 8 PM EDT Wednesday for NJZ004-006-103>108.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...MET/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...MET
AVIATION...JP
MARINE...MET/JT
HYDROLOGY...MET/JT
TIDES/COASTAL FLOODING...
CLIMATE...JT