999
FXUS61 KOKX 141808
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
208 PM EDT Fri Jun 14 2024
.SYNOPSIS...
A cold front will move through the area this evening with high
pressure building in from the northwest behind it. High pressure
becomes centered over the area Sunday morning and moves offshore by
Sunday evening. The high remains in control through late next
week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
Forecast has been updated mostly for cloud cover and PoPs for
the next few hours.
A cold front approaches from the west. The front is currently
over western NY/PA as the associated surface low tracks through
southeast Canada. Aloft, multiple shortwave troughs are
rotating around the broader trough over the northeast US.
We are still on track to potentially see strong to severe
thunderstorms this afternoon and evening. The latest SPC outlook
has expanded the slight risk of severe thunderstorms eastward to
include almost the entire forecast area.
SBCAPEs are mostly 1000-1500 J/kg early this afternoon from NYC
to points N/W. Cloud cover may prevent these CAPEs from
increasing much more, especially with showers in the area, and
more clouds being produced by convection to our west. We can
still potentially get severe wx from thunderstorms as 0-6km
bulk shear increases toward 30-40kt toward the end of the day
combined with the instability in place. Any severe wx would
probably more in the form of wind gusts. Large hail possible as
well with CAPEs possibly approaching 500 J/kg in some areas
within the -10 to -30C region, but mitigated somewhat by
neutral to backing wind profile aloft.
Given the moist environment and skinny CAPE profile, heavy rain
is also possible in any showers or thunderstorms. See hydrology
section below.
The area will likely be dry by the early morning hours on Saturday.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
After an active Friday, the weekend is expected to feature plenty
of sunshine and quiet weather. High pressure slowly builds in behind
the departing cold front as heights rise aloft with an upper level
ridge building over the eastern US. The airmass that will build in
will be cooler and drier. Dewpoints will be in the 40s and 50s both
days, withs highs in the 70s to low 80s. This will give the air a
comfortable feel. We could actually drop to the upper 40s at the
usual cool spots Saturday night as radiational cooling conditions
look ideal.
The center of the high moves offshore by Sunday evening and a return
flow sets up.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
**Key Points**
* Increasing confidence in a prolonged heat wave mid to late next
week. Heat indices may approach or exceed 100F at times,
especially Wednesday through Friday.
* Heat indices greater than 90 are expected as early as Tuesday,
gradually expanding and increasing through the end of the week.
Surface high pressure gradually shifts overhead and offshore on
late Sunday as a large mid and upper level ridge continues to
build over the Eastern CONUS. The surface high pressure
positions itself over the Western Atlantic, allowing for a
persistent southwest to south flow over the area, advecting both
lower level moisture and warm air into the area.
The building ridge amplifies further into the middle to end of the
week, allowing for the development of a close to 600dm ridge over
the Northeast US and SE Canada. A ridge of this strength for mid-
late June over the area would be highly anomalous, though there
still remains uncertainty as to how strong it becomes.
Temperatures at 850mb from Tuesday through at least Friday will
be 18-21C allowing for surface temperatures to reach into the
90s and possibly approaching 100 degrees toward the end of the
week for western portions of the area away from the immediate
coastline. Heat indices may be slightly higher given a SW/S flow
advecting higher moisture into the area. While details as to
the extent of the heat will come into focus as we approach early
next week, this will very likely be the first heat wave of the
season with heat headlines eventually being needed for at least
a portion of the area.
Given the potential duration of the heat, it`ll be important to take
precautions to protect one`s health, particularly those without
effective cooling and/or adequate hydration. Some heat-sensitive
industries and infrastructure will likely be impacted by the extent
of this heat as well.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A pre frontal trough was moving into the lower Hudson Valley and
into northeastern New Jersey at 17Z with showers and an isolated
thunderstorm possible. A cold front will follow late this
afternoon through late tonight.
VFR expected outside of any showers and thunderstorms when MVFR
conditions are expected, with brief IFR possible in stronger
thunderstorms. Timing of the thunderstorms continues to trend
slightly later, with thunderstorms in the NYC metro area 21Z to
01Z, and to the east 23Z to 03Z. Stronger storms, with gusty
winds and small hail possible, will be more likely across the
lower Hudson Valley into northeastern New Jersey, and the NYC
terminals. A few showers will remain possible in the vicinity
of, and post frontal into late tonight.
S to SW winds ahead of the cold front may briefly become light
and variable in the vicinity of the pre frontal trough. Post
cold front winds shift to NW to N and become gusty. Overnight
gusts may be more occasional.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Showers were moving across the terminals, with an isolated
thunderstorm possible, through 20Z.
More organized thunderstorms will become likely late afternoon
into this evening 22Z to 01Z. Timing has trended slightly
later, and that trend may continue. A stronger storm remains
possible with gusts up to 40kt and small hail possible.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday afternoon through Wednesday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A southerly flow will occasionally gust up to 25 kt this
afternoon, otherwise winds and waves are expected to remain
below SCA conditions through early next week.
There is potential for showers and thunderstorms this afternoon
and evening, with the possibility of some being strong to
severe.
&&
.HYDROLOGY...
The entire area is now in a marginal risk of excessive rainfall.
Expecting mostly minor urban poor drainage flooding, but localized
flash flooding cannot be ruled out. Although rain will be heavy at
times, the progressive nature of the thunderstorms is expected to
keep flooding more minor. Probabilities of seeing 1 inch in 1 hour
remain low. Average storm total rainfall amounts will be between
half an inch and 1 inch, with locally higher amounts possible.
&&
.TIDES/COASTAL FLOODING...
There is a high risk for rip current development along Atlantic
facing beaches today with southerly flow 15 to 20 kt along the
shoreline and surf up to 4 ft expected.
Conditions begin to improve by Saturday, with a moderate risk
forecast as winds shift offshore.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075-
080-081-178-179.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JT/MW
NEAR TERM...JC/JT
SHORT TERM...JT
LONG TERM...MW
AVIATION...MET
MARINE...JT/MW
HYDROLOGY...JT/MW
TIDES/COASTAL FLOODING...