Area Forecast Discussion
Issued by NWS Upton, NY
FXUS61 KOKX 011038
Area Forecast Discussion
National Weather Service New York NY
638 AM EDT Sat Oct 1 2016
Little change over the weekend with high pressure to the northeast
and low pressure over the Ohio Valley. The low will then slowly
weaken as it moves toward the region on Monday. Meanwhile, high
pressure will build from the north from Monday night through the
middle of the week, then retreat to the northeast later next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
First in a series of impulses moving up along the coast, with area
of light rain depicted on radar about 50 miles south of Long
Island. This area looks to be dissipating as it works north, but
these pockets of light rain will be common throughout the day,
especially across Long Island and Connecticut. Only minor changes
made to forecast to account for latest conditions.
Not much change in the forecast this weekend as the upper air
pattern will be slow to breakdown with a slowly filling upper
low over the Ohio Valley, and a weakening upper ridge over the
western Atlantic that extends back NW across New England into
Eastern Canada. At the surface, high pressure to the northeast and
low pressure over the Ohio Valley both gradually weaken. More
importantly, this will mean a continuation of a NE flow being
overrun by a southerly winds aloft. Winds though will be
considerably lighter than recent days.
Its real difficult to hone in on any one feature for lift today,
but overall there is weak warm advection and saturated low levels.
Thus, expect a continuation of occasional light rain. drizzle,
and patchy fog.
While its warm aloft, the cool NE flow and cloud cover will keep
highs about 5 degrees below normal, generally 60 to 65.
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
More of the same through Sunday night with a chance of light rain,
drizzle, and patchy fog. However, with the gradual weakening of
both the high to the north and the upper low over the Ohio
Valley, the activity should dissipate in coverage and with time
become more spotty in nature.
Highs on Sunday will be closer to normal as the low-level cold
air across the region begins to slowly erode. Lows will still be
several degrees above normal due to the nighttime cloud cover.
For Mon, although low levels should continue to dry, as upper
trough energy moves overhead, diurnal iso-sct shower activity
possible with cold pool/diurnal instability interacting with
.LONG TERM /TUESDAY THROUGH FRIDAY/...
For Tue, diurnal iso-sct shower activity continues with cold
pool/diurnal instability interacting with residual moisture.
Thereafter, models in good agreement with deep layered ridging
developing for mid to late week with region experiencing a
Canadian Maritime airmass. Meanwhile, the evolution of Hurricane
Matthew will be closely monitored, with forecast sensitivity tied
to the evolution of upper energy as it moves offshore the east
coast mid to late week, the mid to late week evolution of the
trough energy coming into the West Coast this weekend, and the
development of Matthew itself. Refer to the National Hurricane
center forecasts for the latest information.
Temps near or slightly below seasonable through the period.
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
The terminals will remain between high pressure to the northeast and
low pressure to the southwest through Saturday night.
Most terminals will prevail IFR through the TAF period with areas of
drizzle and a NE wind. Conditions may improve at times to MVFR or
worsen to LIFR at times, but this is not expected to become
prevailing, and if they do, it would not be for more than a couple
.Outlook for 06Z Saturday through Wednesday...
.Saturday afternoon...IFR/MVFR in rain.
.Saturday Night-Sunday Night...MVFR or lower possible with showers.
.Monday-Tuesday...Mainly VFR with isolated to scattered showers
.Wednesday...VFR. NE gusts 20-25 kt near the coast.
Northeast winds and waves will continue to diminish today.
However, SCA remains on the ocean waters through late tonight as
waves will be slow to drop below 5 ft. Winds should remain below
25 kt through Tuesday night.
A prolonged period of SCA is possible from Tuesday afternoon
through Thursday night on the ocean waters as seas build to 5 to 9
ft through this time period. NE Winds increase Tuesday, with 25
kt or higher possible for the ocean waters by Wednesday morning
A quarter inch or less of rainfall is expected through Sunday in
mainly light rain/drizzle. An additional tenth of an inch is
possible on Monday in isolated showers.
While tidal departures are gradually forecast to diminish today,
the high tide cycle this morning is several tenths of a foot
higher than last evening. This will likely result in water levels
approaching, and in some cases touching minor coastal flood
benchmarks, across the south shore back bays of Nassau, Queens
and Brooklyn, as well areas adjacent to Lower NY Harbor.
MARINE...Small Craft Advisory until 5 AM EDT Sunday for ANZ350-353-355.