118
FXUS61 KOKX 031940
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
340 PM EDT Thu Oct 3 2024
.SYNOPSIS...
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Weak high pressure will be in place through tonight, and then push
slowly offshore Friday. A weak cold front pushes through late Friday
night into early Saturday. Another, stronger cold front passes
through Sunday night into Monday morning. Cool high pressure then
builds in from the northern Plains through the middle of the
week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Shortwave upper ridging slides east tonight. At the surface,
high pressure remains along the NE US coast.
Diurnal CU will dissipate this evening. Better chance of radiational
cooling tonight with absence of mid-cloud cover. With moderated
humidity levels this will likely lead to scattered areas of fog
development, especially valley, riverine, and outlying coastal
areas late at night. Lows in the 40s across far outlying areas,
to the upper 50s/lower 60s for coast and NYC metro.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
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Shortwave upper ridging continues to slide east on Friday,
allowing a northern stream shortwave to pivot through the region
Friday Night into Saturday AM, and then east Sat afternoon. At
the surface, a weak cold front approaches Friday night and
crosses east Sat AM. High pressure gradually builds in from the
NW Saturday.
Return flow strengthens into Friday, with a warmer and moister
airmass advecting into the region. Morning stratus/fog should
give way to sct (locally bkn) diurnal instability CU under
strong subsidence inversion and to the north of developing sea
breezes. Dry conditions under layered ridging, with temps a few
degrees above on Friday under moderating airmass.
Vigorous shortwave approaches Friday evening and crosses early
Saturday morning, with right front of upper jet lift. Modest theta-e
advection and moisture convergence along/ahead of cold frontal
boundary is a limiting factor for widespread shower activity,
but with strength of shortwave and low-level instability, there
is potential for a period of isolated (coast) to scattered
(interior) showers.
Clearing conditions from w to e Sat AM into early afternoon,
with temps running a few degrees above seasonable in weak caa,
offshore flow, and good mixing.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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Not much change the last 24h with some small timing differences
with a cold frontal passage early Monday.
A fast flow along the US/Canadian border will feature an
amplifying longwave trough over central Canada and into the
Great Lakes that closes off an upper low across across eastern
Canada and the Northeast by midweek. The latter of which will
bring in a below normal (3-5 degrees) airmass Tuesday into
Thursday. The cold front passes through the area by early
afternoon Monday, preceded by a round of showers and isolated
thunderstorms. Instability is marginal, so more likely than not,
thunderstorms will be few and far between. Rainfall amounts at
this point look to be quarter inch or less.
Maintained above normal temperatures in the airmass ahead of
the cold front, using a blend of the NBM and NBM750 for highs
Sunday through Monday. Box and whisker plots showed only a few
degrees between the 25th and 75th, so this is not a big upward
adjustment.
A much cooler airmass will move in behind the cold front with
gusty NW-WNW flow.-- End Changed Discussion --
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
High pressure remains over the area through tonight and then
slides offshore Friday.
Mainly VFR conditions are expected through the TAF period.
There is a low chance of MVFR ceilings and patchy fog late
tonight, mainly KSWF and possibly KHPN.
S winds less than 10kt, and then light and variable this
evening into tonight. S winds 10kt or less Friday.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday through Saturday: Mainly VFR. A slight chance of showers
with MVFR late Friday night into Saturday morning.
Sunday through Monday: VFR Sunday, then a chance of MVFR with a
chance of showers Sunday night into Monday morning.
Tuesday: VFR. Gusty winds possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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Sub-SCA conditions on the waters through Saturday Night with a
weak pressure gradient and subsiding easterly swells.
With long period swells from Hurricane Kirk (see NHC for forecast
details) reaching the area, ocean seas build to 5 to 6 feet Sunday
into Monday. Swells will gradually subside Mon Night into
Tuesday.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic issues are expected throughout the forecast.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...NV/DW
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DW
AVIATION...IRD
MARINE...NV/DW
HYDROLOGY...NV/DW