000
FXUS61 KOKX 231958
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
358 PM EDT Sun Jul 23 2023
.SYNOPSIS...
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Weak high pressure remains in place through Monday. A weak low
may pass nearby to the south Monday night into Tuesday. High
pressure remains over the area mid to late week. A frontal
system may approach the area by the weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Isolated showers and thunderstorms continue across the higher
terrain of northeastern Pennsylvania, northwestern New Jersey,
and into western Orange county New York with weak surface
convergence, and surface based instability and CAPE of 500 to
just over 1000 J/kg. Earlier CAMs have shown the development of
the convection, while the 18Z HRRR has decreased or dissipated
the storms. With the CAPE and instability in place will
continue with the slight chance probabilities through early
this evening as surface instability slowly diminishes and
forecast CIN increases.
Low level riding and surface high pressure remain in place
overnight as an upper trough remains over the northeast.
Overnight temperatures will be near seasonal levels.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
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An upper trough remains over the northeast and along the east
coast Monday through Tuesday as surface high pressure dominates.
A weak shortwave trough approaches late Monday morning into
early Monday night as a weak surface trough develops. A few
showers and thunderstorms are possible as indicated by the CAMS
and global guidance, although there are some timing differences.
With instability increasing late morning with MLCAPE up to 1500
J/kg late morning into the afternoon will have slight chance and
chance probabilities into the early evening across the
interior, while marine influenced areas with a southerly flow
will remain more stable and likely dry.
Another shortwave rotating into the base of the trough into the
mid Atlantic region late Monday night into Tuesday morning
brings a chance of precipitation into the southern
portions/coastal areas. Then with another shortwave and surface
trough developing inland areas will see increased chances for
showers and thunderstorms Tuesday afternoon. Instability will be
better Tuesday as dew points increase into the upper 60s.
Temperatures continue to be seasonable through the period.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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Much of the extended forecast is fairly tranquil with no significant
rain-makers expected through much of the week. The next best chance
for widespread showers or storms will be late week and into the
weekend.
As an upper-level trough departs the area Tuesday night and pushes a
potential frontal wave to the northeast, the large-scale mid-level
flow becomes more zonal with a building ridge to the east. This
allows surface high pressure to build over the East Coast into the
middle of the week. High pressure will allow for generally clear
conditions with light southerly/southwesterly flow each day
beginning on Wednesday. Rising heights and an increase in surface
moisture will allow for temperatures to be on an increasing trend
through the end of the week. High temperatures will be in the upper
80s to low 90s on Wednesday and slowly increase to widespread low to
middle 90s on Friday with some spots nearing 100 in Northeast NJ and
the NYC metro. This heat combined with the dew points in the 70s
will result in widespread heat index values greater than 95 degrees
on both Thursday and Friday. Some spots near the NYC metro may
approach heat index values of 100-103 on Friday.
The heat looks to break Friday night with the approach of a front
bringing in more moderate temperatures and slightly drier air. The
frontal passage may also result in the development of some showers
and thunderstorms, though the timing and extent to the coverage of
these is uncertain at this time. The front and the low pressure
associated with it may impact the area through the weekend.-- End Changed Discussion --
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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Weak high pressure remains over the region today then slides
offshore tonight.
Generally looking at VFR conditions through the TAF period.
Isolated showers have weakened as they approach the local
terminals. Have opted to leave the forecast dry for most
terminals, however can not rule out an isolated shower, mainly
across NYC terminals and to the north and west into early this
evening. A slightly better chance for showers/thunderstorms is
expected Monday afternoon. Have included a PROB30 for TSRA at
KSWF for the afternoon, however with slightly less confidence
further east, have not included PROB30s anywhere else.
Sea breeze at most of the coastal terminals with all coastal
terminals having southerly flow by early this evening. KSWF will
be more variable in wind direction. Winds speeds near 5-10 kt.
Winds lighten this evening, going SW overnight, before becoming
southerly once again Monday afternoon with some terminals
increasing to 10-15 kt Monday afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shifts with seabreeze development may vary by 1-2
hours and could be variable at times.
Can not rule out a brief isolated shower, especially at KEWR and
KTEB both into early this evening and Monday afternoon into early
Monday evening.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon and Tuesday: VFR. A slight chance of a late
day showers/tstms at the NYC metro terminals and northwest.
Wednesday through Thursday: Mainly VFR.
Friday: Mainly VFR, A slight chance of an afternoon thunderstorm.
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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A Marine Weather Statement remains in effect for Long Island
Sound. The National Weather Service in coordination with the
United States Coast Guard have received reports of a large
debris field across Long Island Sound, caused by recent flooding
across New England.
With a weak pressure gradient in place through Thursday, winds
and seas will remain below SCA levels across the forecast
waters through at least Thursday morning. Gusts may approach 25
kt on the ocean by Thursday afternoon.-- End Changed Discussion --
&&
.HYDROLOGY...
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No hydrologic concerns are expected through the end of the
week.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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There is a low rip current risk through this evening with weak
flow and seas less than 3 ft. The rip current risk for Monday
is moderate as the surf height increases to around 3 ft and a
stronger flow is expected.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...MET/MW
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...MW
AVIATION...BC
MARINE...MET/MW
HYDROLOGY...MET/MW
TIDES/COASTAL FLOODING...