discussion on 2024-03-15

000
FXUS61 KOKX 151147
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
747 AM EDT Fri Mar 15 2024

.SYNOPSIS...
Low pressure moves across southern New England this morning,
and then east of the New England coast, bringing a cold front
across the area during the day. Weak high pressure briefly moves
in late today and Saturday. Low pressure passes well north of
the area Sunday, dragging a cold front through the area. As low
pressure lingers over the Canadian Maritimes, a trailing weak
cold front will pass east Sunday night, followed by a stronger
cold front late day Monday into Monday evening. High pressure
will then build to the south on Tuesday. A clipper low will pass
to the north on Wednesday, followed by Canadian high pressure
building from the northwest on Thursday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --A weak low was moving eastward into the the lower Hudson
Valley early this morning, and should move into New England and
off the coast this morning into this afternoon. A cold front
with the low will move south of the area this afternoon. There
was little forcing, and moisture, mainly in the mid levels, with
the front. With the lower levels dry, and surface dew point
depressions 10 to 15 degrees, the showers were weakening as the
area moved into the region, and little precipitation was
reaching the ground. The cold front is now expected to push
farther south than previous forecast, and the CAMs and global
guidance are showing dry conditions by mid afternoon behind the
cold front. A warm air mass remains ahead of the cold front and
highs remain well above normal. MOS guidance and NBM were close
with the highs, which should occur early afternoon, and were
used.-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Weak surface high pressures builds in from the west late today
through Saturday morning, and shifts south during the afternoon
as low pressure tracks north of the Great Lakes. With near
zonal upper flow through Sunday the upper trough remains to the
north, with much of the energy passing just north, or across the
northern edge of the forecast area. Again with little moisture
and upper support little precipitation is expected with a cold
front late Saturday night into Sunday. And with the near zonal
flow cold air is not expected to move into the region, and
temperatures remain well above seasonal normals. Once again used
a blend of the MOS and NBM guidance for temperatures.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Flow aloft becomes quite amplified during this time, with a longwave
trough becoming established over eastern NoAm. One weak front will
slide E Sunday night, followed by fair Wx on Monday and temps close
to normal. Then as the longwave trough amplifies a stronger cold
front will move through late day Monday into Monday evening. This
front looks moisture starved and should go through mostly dry, with
perhaps a stray rain or snow shower well NW of NYC. This will usher
in a colder air mass on a gusty NW flow, with temps running below
normal for Tue and Wed, with highs only in the 40s and lows from the
upper 20s to mid 30s.

A potent nrn stream trough diving out of central Canada will pass
nearby on Tue, with an associated sfc low passing to the northeast.
Most of the forcing with this sys should remain near the sfc low
track, so only have 20 PoP for snow/rain showers NW of NYC daytime
Wed.

NBM captures most of the above details well, but looks too quick to
warm temps up on Thu given low level CAA still ongoing despite
deamplification of the longwave trough and rising heights aloft in
the wake of the departing clipper low.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --Low pressure moving across the lower Hudson Valley and southern
New England this morning will bring a weak cold front through
early this afternoon. Weak high pressure will then briefly move
in later today and tonight.

VFR. There could be some isolated showers with cold fropa, which
looks to occur at about 15Z at KSWF, 16Z-17Z at the NYC
metros/KHPN, 17Z-18Z KISP/KBDR, and 19Z KGON.

Winds should become WSW either side of 10 kt for a couple hrs
right before fropa, then WNW 10-15G20-25kt afterward. Winds then
gradually diminish to under 10 kt this evening while veering N
and then NW late.

LLWS remains for the NYC metros, with W winds 45-50 kt at 2 kft
AGL before cold fropa.

  ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Unscheduled AMD possible to fine tune fropa timing.

OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...

Saturday: VFR.

Sunday: Chance of showers with brief MVFR cond possible inland,
mainly at KSWF and mainly in the morning. SW winds 10-15G20kt in
the morning, becoming W 15G20-25kt in the afternoon, then
diminishing at night.

Monday: VFR. W winds 10-15G20kt, becoming NW at night.

Tuesday: VFR. NW winds 15G20-25kt.

Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --Marginal SCA conditions will be possible on the outer ocean
waters, mainly east of Fire Island Inlet, for a few hours this
morning, as low pressure tracks north of the waters. A westerly
flow will then develop behind the low and winds and seas will
fall below SCA levels for the afternoon.

Sub SCA conditions will remain on the forecast waters tonight
through Saturday night as weak high pressure builds over the
area. Sunday low pressure will be tracking well to the north of
the forecast waters and an increasing southerly flow ahead of a
cold front will allow for SCA conditions to develop on the
ocean. Small craft advisory conditions will be possible on the
non ocean waters Sunday afternoon.

SCA cond likely on most if not all waters from late day Mon into
Tue evening with and following a cold frontal passage, with NW
flow gusting up to 30 kt on the ocean and 25 kt elsewhere. With
offshore flow ocean seas should get no higher than 4-6 ft.
Minimal SCA cond should linger on the ocean into the rest of Tue
night.-- End Changed Discussion --

&&

.HYDROLOGY...
No hydrologic impacts are expected today through late next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS/MARINE/HYDROLOGY...BG/MET
NEAR TERM/SHORT TERM...MET
LONG TERM/AVIATION...BG