okx-afd on 2024-06-23

751
FXUS61 KOKX 232054
AFDOKX

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

.SYNOPSIS...
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.

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --Severe Thunderstorm Watch was issued for Orange and Putnam
counties until 8 pm. Main threat is damaging winds, but can`t
rule out large hail or even an isolated tornado. 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 late this afternoon, 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.-- End Changed Discussion --

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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.

.LONG TERM /TUESDAY THROUGH SUNDAY/...
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.

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --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 this eve but shwrs and tstms expected to develop.
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 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...

Isold tstm development possibly 21-23Z. Timing and coverage of
convection thru tngt 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-- End Changed Discussion --

.MARINE...
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.

.HYDROLOGY...
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.

.TIDES/COASTAL FLOODING...
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.

.CLIMATE...
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)

.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...JMC/JE
MARINE...DBR/DR
HYDROLOGY...DBR/DR
TIDES/COASTAL FLOODING...
CLIMATE...