000
FXUS61 KOKX 060952
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
552 AM EDT Tue Jun 6 2023
.SYNOPSIS...
Low pressure over the Canadian Maritimes remains nearly
stationary through midweek, sending a cold front through the
area this afternoon. The low will then weaken the second half of
the week drifting south into the Gulf of Maine. Weak high
pressure builds in Saturday and moves offshore Sunday as a cold
front approaches. The front moves through the region late Sunday
into Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Smoke from wildfires across eastern Canada working across across
the area with some visibility restrictions down to 5sm. With the
onset of daytime heating and mixing, visibilities should
improve, but haze and possibly odor will remain.
A cutoff low will remain over the Canadian Maritimes through the
end of the week, gradually weakening during this time. An omega
block across North America will result in very little change
in the upper air pattern during this time as a series of
fronts/troughs drop across the area. The first of which will
move across the area this afternoon. Steep lapse rates (7C) from
the surface into the mid levels will combine with marginal to
moderate instability to produce scattered showers and a few
thunderstorms, mainly this afternoon. A significant dry sub-cloud
layer could be a limiting factor for instability, however, it
cold also enhance gusty surface winds. CSU Machine Learning
Severe probabilities shows a marginal risk for hail and wind.
This scenario would seem more plausible were the NAM profiles
with CAPE values approaching 1000 J/KG realized. The GFS has
considerably less instability with its extremely deep mixed
layer, while the HRRR and SPC HREF show values in the 500-750
J/KG range. Current thinking is that this will be a sub-severe
event. The best chance for convection looks to be this afternoon
with not only cold front but with a mid level short wave
dropping down the backside of the upper low. Rainfall amounts
will should be under a quarter inch.
NW winds at times today may gusts as high as 20 to 25 mph. This
combined with the low RH values (30 to 35 percent) across NE NJ
will enhance the spread of any brush fires that do develop.
In addition, the HRRR and RAP continue to show high
concentrations of smoke in the low levels today into this
evening. Thus, have maintained smoke and haze in the forecast
into tonight. This potential looks to continue beyond this time.
Highs today will be near seasonable levels in the 70s, perhaps
around 80 across metro NE NJ. Lows behind the cold front tonight
will be a few degrees below, ranging from the upper 40s inland,
to the upper 50s across NYC.-- End Changed Discussion --
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
Deep-layered cyclonic flow and disturbances rotating about the
upper low will bring clouds each afternoon with a chance of
showers. There will be a bit more instability Thursday afternoon
and perhaps an isolated thunderstorm north and west of the NYC
metro. Temperatures will gradually cool down through Thursday.
For Thursday, leaned toward the cooler MOS versus the NBM due to
more cloud cover as the upper low retrogrades west across
northern New England.
Smoke and haze issues may linger into Wednesday, especially for
the western half of the forecast area.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Omega blocking will persist into Saturday as a large closed
upper low remains over the northeast and into eastern Canada.
The low weakens Saturday and drifts northeast as additional
energy rotates into the upper trough. That low deepens and
becomes closed off Sunday and remains into Monday. Overall, the
extended period will be unsettled except for a brief dry period
late Saturday into Sunday as weak ridging builds into the
northeast. Temperatures will be generally just below seasonal
normal levels, except for Sunday with the ridge and dry weather.
There is a chance of showers into Saturday with a slight chance
of thunderstorms inland late Friday where there will be better
instability and forcing. Additional showers and thunderstorms will
be possible with a cold front Sunday and Monday. Generally
followed the NBM guidance except with a few adjustments to the
probabilities.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
A cold front will approach early this afternoon and move through
during through mid to late afternoon.
MVFR cond are possible with any TSRA that develops ahead of the
approaching front early afternoon at KSWF and mid afternoon farther
SE. Strongest cells may even produce gusty winds and hail. Best
chance of thunder should be at the CT and Long Island terminals,
especially KGON where brief IFR cond may be possible.
Light WNW should increase by afternoon, with gusts near or just over
20 kt. Winds shift NW after fropa, them diminish this evening.
Smoke from Quebec wildfires will limit slant range visibility at
times today, also sfc visibility in the NYC metro area and lower
Hudson Valley for a few hours late today after cold fropa.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
The afternoon haze potential forecast is YELLOW, which implies slant
range visibility 4-6SM outside of cloud.
AMD may be needed today to pinpoint tstm timing/coverage.
OUTLOOK FOR 06Z TUESDAY THROUGH SATURDAY...
Late tonight: VFR.
Wednesday: VFR. W-NW winds G20kt. MVFR vsby again possible in
smoke/haze at the NYC metros from 20Z-24Z.
Thursday through Friday: Mainly VFR. Chance of afternoon and early
evening showers both days.
Saturday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Winds and seas likely remain below SCA levels through Saturday
night as low pressure over the Canadian Maritimes weakens. Weak
low pressure will then remain in the vicinity of the forecast
waters through Saturday.
&&
.FIRE WEATHER...
-- Changed Discussion --
NW winds at times today may gust as high as 20 to 25 mph. This
combined with the low RH values (30 to 35 percent) across NE NJ
will enhance the spread of any brush fires that do develop.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic impacts expected through the beginning of next week.
&&
.TIDES/COASTAL FLOODING...
Low pressure over the Canadian Maritimes continues to produce E
swell that in tandem with high astronomical tides is keeping water
levels higher than usual, especially in the back bays of Nassau.
Followed the Stevens NYHOPS bias-corrected central forecast and
issued a coastal flood advisory is in effect for the high tide cycle
late this evening. Water levels there may barely touch minor
thresholds with the high tide cycles both Wed/Thu nights as well.
There is a low risk for the development of rip currents at the
ocean beaches today and Wednesday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Coastal Flood Advisory from 9 PM this evening to midnight EDT
tonight for NYZ179.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...MET/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...MET
AVIATION...BG
MARINE...MET/DW
FIRE WEATHER...
HYDROLOGY...MET/DW
TIDES/COASTAL FLOODING...BG