000
FXUS61 KOKX 010014
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
814 PM EDT Fri Jun 30 2023
.SYNOPSIS...
High pressure weakens and will become based in the Western Atlantic
tonight into Saturday. A warm front approaches Saturday night. A
warm front moves through Sunday into Sunday night. A cold front
approaches Monday and likely pushes through into Tuesday. Weak
high pressure should assume control Wednesday and Thursday. A
cold front may approach towards the end of the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
For this update the only slight adjustment was to prolong haze
in weather grids for a bit longer in the night.
With a weak pressure gradient and diurnal cooling, winds will
decrease and will remain light. These winds will be southerly
and will allow for a relatively warmer night on average compared
to the previous night. No rain is expected.
A little more cooling across interior and eastern locations
with more maritime influence will allow for any fog to develop
in these locations first with more development elsewhere closer
to daybreak Saturday. Kept fog forecast coverage at patchy and
mainly east with model uncertainty in surface visibilities.
Concerning the residual smoke and haze, according to the HRRR,
the concentration lowers along the southern and coastal portions
of the region where winds will be relatively higher. However,
the residual smoke and haze is forecast to linger across
interior areas north and west of NYC this evening getting
gradually less later at night. In essence, less smoke and haze
overall is forecast later in the overnight.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
For Saturday, there is more SE flow and this will increase
across the coastal sections of the forecast region with high
pressure centered well out into the Atlantic. This will make
for an increase in spatial temperature gradient with warmer
temperatures across western sections of the forecast region and
cooler temperatures across the coastal sections. The range of
max temperatures will be upper 70s to mid 80s with some
localized spots in the upper 80s in NE NJ. Mainly sunny sky
conditions to start the day with any residual fog burning off in
the morning. Clouds increase in the afternoon.
For Saturday night, the continued onshore southeast flow will
result in an increase in humidity as well as relatively warmer
temperatures with abundant cloud coverage. A warm front
approaches late and could allow for some rain shower development
across far western sections overnight. Otherwise, expecting
more patchy fog which could be more expansive along the coast.
Due to model uncertainty, left as patchy fog coverage. Lows are
forecast to range from the mid 60s to near 70 across the area.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
Sunday at this time looks to be the first day the area gets into the
warm sector. With the moisture content in the column increasing
during the day, look for scattered to isolated shower and t-storm
activity. Any potential hazardous weather on Sunday would likely be
localized heavy rain in association with any thunderstorms that can
form on weaker boundaries, perhaps sea breeze boundaries. The latest
guidance is indicating an overall lack of instability to start on
Sunday, with perhaps instability increasing, at least elevated
instability later Sun and Sun night. WPC has a marginal risk of
severe weather for Sunday and Sunday night; mainly for the southern
half of the area. The mid and upper levels may not be primed with a
lack of cyclonic curvature / vorticity in the mid and upper levels
during the day Sunday.
By Monday the thunderstorm / severe weather potential looks more
favorable at this point in terms of the synoptic set up. The area
will be deeply embedded in the warm sector. Dew points look to be
likely in the lower 70s across a good portion of the region with a
pre-frontal trough getting into the area. The mid levels will have
more cyclonic curvature with medium range guidance suggestive of
shortwave energy pivoting into the region. BUFKIT soundings from the
GFS indicate the potential for multiple hazards in relation to t-
storm activity. PWATs look to be off the charts from a climo
perspective, at or just above 2 inches. There also appears to be
adequate shear for storm organization. What is not predictable this
far out is if any mitigating factor such as morning cloud cover
which would limit more widespread severe t-storm potential. In any
event, Monday looks to be a day to keep an eye on.
By Tuesday the 4th, look for the southern portion of the mid /
upper level trough axis to push through at some point during the
morning or perhaps as late as the early afternoon. If the
system moves slower any shower and t-storm activity from Mon
evening could linger into early Tue morning. In the lower levels
it seems likely somewhat drier air begins to filter in with a
cold frontal passage. It would seem with a trough aloft that
there would at least be a chance of some scattered afternoon
convection on Tue, especially further north and east across the
area.
Mid levels heights should recover enough to promote a cap on any
convection getting into the mid week beginning on Wed, and likely
lasting through the first half of Fri. Kept PoPs minimal for the Wed
through early Fri time frame, then start to increase PoPs from west
to east on Fri as the next frontal system arrives based on global
model consensus.
With respect to temperatures, look for minimum temperatures to
average a bit above normal through the period due to mainly higher
overall humidity. Daytime maxes should average below normal on
Sunday due to cloud cover, and then approach more normal levels on
Monday with some afternoon breaks of sun. For the remainder of the
next week look for daytime maxes to average a few degrees above
normal, especially across urban areas and across the interior.-- End Changed Discussion --
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Weak high pressure passes offshore today.
Smoke haze continues to lead to MVFR vsbys, generally 3-5SM, with
gradually improvement to VFR into the evening.
S or SE flow around 10 kt lightens this evening, backing a bit more
SE on Saturday.
THE AFTERNOON KJFK, KLGA, KEWR HAZE POTENTIAL FORECAST IS
RED...WHICH IMPLIES SLANT RANGE VISIBILITY LESS THAN 4SM OUTSIDE OF
CLOUD.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low confidence overall in vsby forecast with smoke haze. Timing of
vsby improvement may be off by several hours. Amendments possible.
OUTLOOK FOR 18Z SATURDAY THROUGH TUESDAY...
Saturday: VFR. SE 10 kt or less.
Saturday Night and Sunday: Showers possible and chance of tstms.
MVFR likely at times, IFR possible with this activity.
Monday and Tuesday: Chance of afternoon/evening showers/tstms,
otherwise VFR.
Wednesday: Mainly VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
With a weak pressure gradient in place across the forecast
waters through Saturday night, conditions are expected to remain
below small craft advisory thresholds.
Sub small craft conditions take place on Sunday with ocean seas
around 4 ft and gusts up to 20 kt. Marginal small craft conditions
are expected out on the ocean Monday afternoon and evening just
ahead of a cold front on a S to SSW flow with 4 to 5 ft seas. On
Tuesday 4 ft seas are expected before seas decrease to around 3 ft
into Wednesday with the winds mainly out of the SW to S.
There will be a chance of thunderstorms Sunday, Monday, and Tuesday,
with the best chance at more widespread thunderstorm activity on
Monday. On these days there could be locally hazardous conditions in
relation to thunderstorms.
&&
.HYDROLOGY...
No hydrologic issues expected through Saturday night with no
widespread heavy rainfall expected.
There will be a localized threat for flooding in association with
any stronger t-storms producing heavy rain on Sunday. Currently WPC
has a marginal risk of excessive rainfall on Sunday. On Monday there
remains a risk of localized flooding with any stronger t-storms.
There will be no hydrologic impacts for the remainder of the week,
Tuesday through Friday.
&&
.TIDES/COASTAL FLOODING...
A moderate risk of rip currents is expected Saturday into Sunday
morning. A high risk of rip current development can be expected
towards Sunday afternoon and evening for the NYC, Nassau, and SW
Suffolk beaches, with a moderate risk being maintained for the E
Suffolk beaches.
With astronomical tides increasing this weekend with the approach of
a full moon on Monday, minor coastal flooding looks possible to
likely with the evening high tide cycles for Sunday and Monday.
Areas most likely to be affected are the south shore bays of Nassau,
Queens and Brooklyn, Staten Island, and Southern Fairfield /
Westchester Counties.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/JM
NEAR TERM...JE/JM
SHORT TERM...JM
LONG TERM...JE
AVIATION...DR
MARINE...JE/JM
HYDROLOGY...JE/JM
TIDES/COASTAL FLOODING...