000
FXUS61 KOKX 291748
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
148 PM EDT Thu Jun 29 2023
.SYNOPSIS...
Weak high pressure will be in place today through Friday. A warm
front then approaches on Saturday and begins to move through the
region during Saturday night. The frontal system will then
stall near the area Sunday through the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
No changes for this update with lower visibilities related to
Canadian wildfire smoke plume residing just to the west and for
the far western and southwestern edge of the CWA.
Weak high pressure will be in place this afternoon with perhaps
a weak trough of low pressure extending into northeastern
sections from New England. Moisture convergence and daytime
instability may help trigger an isolated shower over NE portions
of So. CT this afternoon, and have chosen to keep slight chance
of showers here, otherwise it is dry conditions this afternoon
and tonight. It`ll feel a little less humid than the past few
afternoons as dewpoints will be generally 60-65. Based on
progged temps at the top of the mixed layer, thinking is NBM is
a little too cool for high temps in most spots unaffected by a
sea breeze this afternoon. A blend of 50th and 75th percentile
was used.
Based on obs and HRRR smoke forecast, have left in a mention of haze
today and tonight from around the Hudson River, including NYC
to points west. Have added portions of Western LI and Western
So. CT to haze in wx grids.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure will still be dominant on Friday, however
convection firing up ahead of a warm front and PVA aloft well to
our west will try to hold together and sneak in over the
westernmost part of the forecast area late in the day. Good
chance the entire day remains dry everywhere. Highs generally in
the 80s.
The warm front is associated with a low pressure system slowly
tracking through the Great Lakes region. Chances of showers slowly
shift east along with it, and the western half of the forecast area
will stand a chance of some rainfall by Saturday morning.
For Saturday, the front draws nearer but also weakens. NBM PoPs may
be too high, especially with upward forcing appearing to be lacking
and CAPE tempered by a weak onshore flow. Didn`t have enough
confidence to lower PoPs too much from the previous forecast, so
have kept with showers increasing from chance to likely NW of the
city in the afternoon. Chances of showers elsewhere. Can`t rule out
a rumble of thunder everywhere except eastern LI and SE CT. The warm
front then begins to shift through the forecast area Saturday night.
A little better forcing with isentropic lift along with deepening
moisture increases rain chances a little from the afternoon. An
isolated thunderstorm is still possible.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
An unsettled period is expected in the long term as a weak frontal
system lingers over the area. A plume of high moisture air
consisting of 2-2.25 inch pwat values will move into the area Sunday
and could stick around through Tuesday. These pwats are above the
max moving average for this time of year per SPC`s Sounding
Climatology Page. After mainly zonal flow aloft on Sunday, a trough
will approach and be slow to pass to our east. This set up will
likely result in showers and thunderstorms each day. At this time,
widespread hydrologic impacts are not expected. The WPC has outlined
portions of northeast NJ and the Lower Hudson Valley in a marginal
risk in the Day 4 and 5 ERO. Additionally, the experimental CSU
machine learning severe weather forecasts have our area in a
marginal risk of severe weather each day.
Temperatures will run right about average, with highs in the 80s
each day and a slight warming trend. Given the high moisture and
lack of clear nights, lows will be well above average, in the upper
60s to low 70s.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
Weak high pressure remains over the area through Friday.
VFR today with a NW flow at most terminals right now. Coastal
sea breezes have developed and are expected to impact terminals
this afternoon.
Some haze from smoke is likely from the NYC metros north/west
during much of the daytime hours. The haze could cause vsby to
drop to MVFR at KEWR and KTEB this afternoon through the
evening. The sea breeze should help improve vsby at the
terminals it passes through.
Winds tonight become light and variable tonight, then the
synoptic flow becomes southerly for Friday. No plans at this
time to include any haze from the smoke in the forecast for
Friday at this time.
THE AFTERNOON KJFK, LGA, AND EWR HAZE POTENTIAL FORECAST IS
YELLOW...WHICH IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF
CLOUD.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible for timing of sea breezes this afternoon.
Low confidence in vsby forecast this afternoon and evening with
smoke haze.
OUTLOOK FOR 18Z FRIDAY THROUGH MONDAY...
Friday: VFR.
Friday night: Chance of showers/MVFR cond, with possibly a tstm at
KSWF.
Saturday and Sunday: Showers likely and chance of tstms, mainly each
afternoon/evening. MVFR expected, IFR possible with this activity.
Monday and Tuesday: MVFR possible. Chance of mainly
afternoon/evening showers and thunderstorms.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Sub-advisory conditions are expected to prevail through
Wednesday with a weak pressure gradient in place an a lack of
significant swell. However, there will be a slight chance to
chance of thunderstorms each day, starting on Saturday, which
could result in locally hazardous conditions.-- End Changed Discussion --
&&
.HYDROLOGY...
No anticipated hydrologic impacts through Wednesday.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
For this afternoon, there is a high risk of rip current develop
along the Atlantic beaches of Suffolk County as a 9-11 second
SE swell period continues with the surf averaging around 4 ft.
Elsewhere, a moderate risk is expected today. There is then a
moderate risk of rip current development for Friday everywhere.
With astronomical tides increasing this weekend as we head toward a
full moon on Monday, minor coastal flooding will be possible with
the evening high tide cycles Saturday through at least Monday. Areas
most likely to be affected are the south shore bays of Nassau,
Queens and Brooklyn, along lower NY Harbor, and Southern
Fairfield/Westchester Counties.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Rip Current Risk until 9 PM EDT this evening for NYZ080-
081.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/JT
NEAR TERM...JC/JE
SHORT TERM...JC
LONG TERM...JT
AVIATION...BC
MARINE...JC/JT
HYDROLOGY...JC/JT
TIDES/COASTAL FLOODING...