000
FXUS61 KOKX 041139
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
739 AM EDT Thu Apr 4 2024
.SYNOPSIS...
Low pressure passes near Long Island this morning, before
tracking northeast along the New England coast later today. This
low will remain near eastern New England on Friday, then exit
east into the Atlantic Saturday into Sunday. High pressure will
return on Monday. A back door cold front may approach from the
northeast Tuesday into Wednesday as a weakening frontal system
approaches from the west.
&&
.NEAR TERM /THROUGH TONIGHT/...
Deepening 988 mb surface low due south of Montauk at 1030Z
will slowly trek north and east into coastal New England today.
One last area of showers pivoting through southern Connecticut
and eastern Long Island should begin to wind down thru the
morning, especially for coastal areas. As colder air works in
behind the low, the rain has been able to mix with or change
over to a wet snow in some of the elevated interior locales of
the Lower Hudson Valley and SW CT. Little to no additional
accumulation is expected in these areas, and temperatures remain
above freezing. Forecast remains on track and previous
discussion follows.
The sprawling associated upper low centered near the Ohio
Valley will work east through the day and keep a chance for a
few showers. As the surface low passes farther to the east,
winds will back around to a more northerly direction and
continue to weaken. A few showers will continue to be possible
into the afternoon, CAMs indicate these should be spotty at best
and conditions remain predominantly dry with QPF under a tenth
of an inch.
PoPs increase once again however late in the afternoon and
early this evening with additional shortwave energy rotating
around the passing upper low. A bit of uncertainty in where this
axis of showers sets up exactly, though best chances locally
look to be across NE NJ, NYC, and points south and west. The
shower activity shuts off tonight as the upper low passes east
into New England.
Highs today run below normal for early April as colder air
advects down in the NW flow. Soundings prog 850 mb temps falling
to around -5C this afternoon, which should translate to 40s for
most and low 50s in the urban NYC metro, about 5 to 10 degrees
below normal. Overnight lows fall back into the 30s.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
An omega block over North America translates slowly east on
Friday. Surface low pressure meanders along coastal New England
as the upper low is slow to depart. The cyclonic flow should
keep skies more cloudy than not, with perhaps some scattered
shower activity developing during the day, though not a washout.
Temperatures top out in the upper 40s and lower 50s.
As the associated upper low starts to move southward with a leading
spoke of mid level vorticity moving across late Fri night, chances
for light rain/snow showers should increase inland Fri evening, and
mainly E of NYC late Fri night into Sat.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
No significant changes in long term thinking. Precip chances
should come to an end by Sat night, and Sunday looks dry with
partly sunny skies across S CT/Long Island and mostly sunny
skies to the west.
Noticeably milder wx arrives on Mon with high pressure sfc and
aloft building in, with high temps mostly in the lower/mid
60s, except upper 50s across ern Long Island and along south
facing shorelines. Model fcsts also continue to show a mid level
shortwave trough to the west riding atop the upper ridge axis
Mon afternoon, which could produce a fair amt of high clouds
during the time of the solar eclipse.
Fcst details become more uncertain beyond Mon night as guidance
shows the upper ridge strengthening a little, while a closed low
drops SE across the Canadian Maritimes, which should send a
back door cold front toward the area from New England, and an
upper low either approaches the western Great Lakes or gets
shunted into central Canada. Splitting the difference between
the GFS and ECMWF on timing of any back door cold fropa, with
Tue on the mild side (a few deg warmer than Mon) and somewhat
cooler temps for Wed, also slight chance PoP from Tue night into
Wed.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Low pressure east of Long Island will move northeast through
the day.
Generally VFR/MVFR with IFR east of NYC. Conditions will gradually
improve to VFR, mainly after 18Z. Additional showers (rain/snow
mix at KSWF) and MVFR conditions will be possible again this
evening into the first part of tonight. Conditions improve back
to VFR after midnight.
Winds today will be from the N to NW with speeds 10-15kt with
gusts this morning and early afternoon to 20-25kt. The gusts end
and wind speeds diminish after 18-20z. Wind speeds increase and
gusts return Friday morning.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible today changing flight categories.
An occasional wind gust may be higher than forecast. Timing of
wind gusts may be off by an hour or two.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday: Mainly VFR. Possible rain shower with pockets of MVFR
conditions. NW flow with gusts 20-25kt.
Saturday: Mainly VFR. Northerly gusts around 20 kt.
Sunday: VFR with northerly gusts near 20 kt.
Monday: VFR with light winds.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Storm Warnings have been converted to Small Craft Advisories on
all waters this morning as winds have begun to come down with
low pressure passing east. NW flow on the backside of the low
will lighten through the morning, and SCA conditions should come
to an end on most sheltered waters by late morning. SCA in
effect on these zones til 15Z, though it`s possible conditions
improve before this.
The exception is on the ocean, where SCA continues through at
least Friday night due to elevated seas as low pressure meanders
off the New England coast. Some gusts up to 25 kt are also
possible on the non ocean waters Fri afternoon/evening. SCA cond
also possible in N flow on the ern ocean waters late Sat night
into Sunday morning as low pressure finally pulls away to the
east.
&&
.HYDROLOGY...
While additional showers are expected across the region today and
Friday, the threat for flooding from heavy rain has come to an
end.
A few streams in NE NJ may continue to rise due to excess runoff
from earlier rainfall but significant hydrological issues are
not expected into early next week.
&&
.TIDES/COASTAL FLOODING...
The higher of the two high tide cycles is currently occurring
or will occur later this morning with the potential for
widespread moderate flooding (and a low end chance of reaching
major for the southern and eastern bays of Long Island) early
this morning.
Along the oceanfront, breaking waves of 6-10 ft into this morning,
along with elevated water levels, will result in widespread
beach flooding and erosion. Scattered areas of dune erosion with
localized overwashes are likely during the times of high tide
this morning.
For most locations, this will be the last of the coastal flooding,
however a few spots may just touch minor with the Friday morning
high tide. The main concern will be along the South Shore Bays of
Long Island. With the last high tide cycle falling well short of the
forecast, and this mornings high tide cycle not yet complete, will
allow the day shift to re-evaluate the need for any additional
headlines.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Warning until 10 AM EDT this morning for
CTZ009>012.
NY...Coastal Flood Warning until 10 AM EDT this morning for NYZ071-
073-078-176-177.
Coastal Flood Warning until noon EDT today for NYZ079>081-179.
NJ...None.
MARINE...Small Craft Advisory until 11 AM EDT this morning for ANZ331-
332-335-338-340-345.
Small Craft Advisory until 4 AM EDT Friday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...BG
AVIATION...BC
MARINE...BG/DR
HYDROLOGY...DR
TIDES/COASTAL FLOODING...