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692
FXUS61 KOKX 232023
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
423 PM EDT Sun Jun 23 2024

.SYNOPSIS...
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A cold front approaches tonight and moves through into early
Monday morning. High pressure then builds in from the Midwest,
moving across the area Tuesday as a cold front approaches from the
west. The front crosses the region Wednesday night into Thursday
morning. High pressure will then return for Thursday night into
Friday, and move off the northeast coast Saturday as another cold
front begins to approach.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Approaching surface cold front is just beginning to push into
western PA and far western NY, but will eventually advance into
the local Tri-State overnight. Ahead of this a prefrontal
trough is helping to initiate scattered convection late this
afternoon, mainly off to the north and west, but some activity
has been able to work into the lower Hudson Valley and NE NJ.
Certainly a moist environment to work with as surface dew pts
are near 70 and a developing LLJ will only add to the moisture
in the column. SPC mesoanalysis indicates SBCAPE well over 2000
J/kg across NE NJ and the lower Hudson Valley, and effective
shear values approach or exceed 40 kt in this same area, which
supports at least the potential for any convection that develops
to become severe. Timing of this threat appears to be a bit
later than recent days, beginning likely after 3 or 4 pm, and
then persisting into the evening. Possible an additional round
moves through overnight just ahead of the front based on some of
the CAMs output, and this will need to be monitored.

SPC has placed the entire area in a slight risk for severe
thunderstorms, with the main threats being damaging winds and
isolated tornadoes. Large hail is also a threat, mainly across
the Lower Hudson Valley and southern CT. Along with the severe
threat, there is the threat for flash flooding with PWAT values
toward two inches. The Weather Prediction Center has placed the
entire area in a marginal risk for excessive rainfall, with
minor flooding possible under any thunderstorm. Widespread hydro
issues appear unlikely with the progressive nature of this
system.

Heat Advisory remains in effect until 8 pm this evening for most
zones. No extension is needed as temperatures fall back behind
the cold frontal passage on Monday. Another warm night ahead of the
boundary with lows mainly in the 70s.
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&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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Behind the fropa, surface high pressure builds in from the Midwest,
offering a dry reprieve from the heat and humidity. Heights
quickly fall as the ridge breaks down and a closed low trough
swings east over New England.

Cooler air mass advects in on the NW flow aloft, and temperatures
in the afternoon top out in the low to mid 80s for most, but
will feel much more tolerable as dew pts fall a good 10 degrees
from Sunday, into the low 60s. Absent a spotty shower well
inland, otherwise a mostly dry day can be expected. Plenty of
diurnal cu is likely to develop though as the cold pool moves
overhead. Monday night is dry, with clearing skies as the
surface high builds closer. Overnight lows in the 60s.
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&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
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Key Points:

* Temperatures will remain near to just above normal, with Wednesday
  the warmest and most humid day of the period.

* A slow moving cold front may bring locally heavy rainfall from
  late day Wednesday through Wednesday night.

Global ensemble guidance continues to remain in decent agreement for
next week and as such, there has not been much change to the
forecast with this update.  The National Blend of Models was
followed closely.

Shortwave ridging on Tuesday gives way to a more zonal flow by
Wednesday into Thursday. A deepening shortwave trough passes through
the area on Thursday followed by weak ridging again into next
weekend. Much of the week looks to remain dry, save for a frontal
system that approaches from the west Wednesday night into Thursday.
The timing of this feature is perhaps a bit earlier than yesterday
in the global guidance, passing through the region by 12Z Thursday.
Modeled PWATS of close to 2" (near the max for the date from SPC
sounding climo.) along with a weak steering flow aloft would
increase the chances of excessive rainfall for the area as the front
passes through the area overnight Wednesday into Thursday. However,
the probability of more than 1" in 6 hours from the NBM remains less
than 10% for the entire area, perhaps hinting at a more localized
threat.

While high temperatures next week will be in the upper 80s and low
90s, dewpoints in the low to mid 60s will limit the excessive
heat/heat index potential. High temperatures on Wednesday look to be
near 95F across the urban corridor of NYC and NJ and upper 80s
elsewhere. With dewpoints in the mid to upper 60s, this will yield
heat indices in the mid to upper 90s across the hottest locations.
Thereafter, the front passes through and Thursday/Friday are a bit
cooler, but still above average, in the mid to upper 80s.

Dry weather returns Friday and Saturday as another high builds into
the region.
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&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
A warm front to the north continues to move northward. A cold front
moves into the area late tonight into Monday morning. High pressure
builds in late on Monday.

Mainly VFR for today, but with showers and thunderstorms towards
late afternoon and evening. This will bring pockets of brief MVFR
conditions. Some storms could produce heavy rainfall and strong
gusty winds. Expect gusty winds with any thunderstorms, and a few
storms may produce gusts as high as 60 kt, although timing and areal
extent is quite uncertain. Have two TEMPO group for thunderstorms;
the second TEMPO group towards midnight for the city terminals and a
few hours later for the more eastern terminals. Uncertainty remains
higher than average for both TEMPO groups. Some lower ceilings may
briefly impact far eastern terminals late in the overnight before
the frontal passage.

S winds gradually increase through the afternoon with sustained
around 15 kt, with gusts 25-30 kt for some southern coastal
terminals. There may be an occasional higher gust near the coast.
And stronger gusty winds are possible in and near thunderstorms.

 NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing and coverage of convection towards this evening and during
the overnight remains highly uncertain.


OUTLOOK FOR 18Z MONDAY THROUGH THURSDAY...

Monday afternoon: VFR. W to NW wind G20-25 kt.

Tuesday: VFR.

Wednesday: Mainly VFR. A chance of showers and thunderstorms in the
late  afternoon and at night, with MVFR or lower possible. SW wind
15-20 kt G20-25 kt near the coast.

Thursday: MVFR or lower possible early with a chance of showers,
then VFR.

Friday: VFR.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
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Small Craft Advisory in effect for all waters but the NY
Harbor. Southerly flow will continue to gust 25 to 30 kt into
this evening and there may be occasional gusts to gale force on
the ocean. Ocean seas approach 8 to 10 ft late tonight. A
frontal passage overnight will allow winds, and eventually seas,
to subside on Monday. Seas likely still linger at or above 5 ft
into Monday evening before calming.

Winds and seas across all the forecast waters then remain below
advisory levels Tuesday and Tuesday night. Increasing southerly
winds ahead of an approaching cold front Wednesday and
Wednesday night will allow for conditions on the oceans to
approach SCA levels. Ocean seas may remain near SCA levels
through Thursday as winds shift to west behind the cold front.
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&&

.HYDROLOGY...
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WPC has placed the entire area in a marginal risk of excessive
rainfall today. With a very humid airmass in place any
thunderstorms that develop could produce heavy downpours that
lead to minor, nuisance flooding. Localized flash flooding
cannot be ruled out.

There is a chance for locally heavy rain from late day Wednesday
afternoon into Wednesday night with a front moving through the
region.
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&&

.TIDES/COASTAL FLOODING...
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A high rip current risk continues through Monday for all ocean
beaches mainly due to an energetic S swell. The risk lowers to
moderate on Tuesday as seas subside and a wind trajectory offshore
for much of the day.
-- End Changed Discussion --

&&

.CLIMATE...
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Here are current record high temperatures for today...

Sunday, June 23

NYC: 96(1888)
LGA: 95(1965)
JFK: 94(2010)
EWR: 97(1965)
ISP: 91(1999)
BDR: 91(2010)
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ005>011.
NY...Heat Advisory until 8 PM EDT this evening for NYZ067>075-078-
     176>179.
     High Risk for Rip Currents through Monday evening for NYZ075-080-
     081-178-179.
NJ...Heat Advisory until 8 PM EDT this evening for NJZ002-004-006-
     103>108.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ331-332-
     335-340-345.
     Small Craft Advisory until 6 PM EDT Monday for ANZ350-353-355.

&&

$$

SYNOPSIS...DBR/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...DBR
AVIATION...JE
MARINE...DBR/DR
HYDROLOGY...DBR/DR
TIDES/COASTAL FLOODING...JE
CLIMATE...