000
FXUS61 KOKX 302322
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
722 PM EDT Sat Mar 30 2024
.SYNOPSIS...
A series of weak lows will impact the area through Monday. The
first of which will pass to the south of Long Island tonight,
followed by weak high pressure on Sunday. The second system, a
frontal wave, will then approach from the west Sunday night,
also passing to the south on Monday. The associated frontal
boundary sets up south of the area into Tuesday as low pressure
approaches from the west. The low reorganizes and intensifies
nearby Wednesday before drifting slowly to the northeast
Thursday and Friday. High pressure off to the west builds slowly
next weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
For this update adjusted clouds and PoPs slightly through the
remainder of the evening to adjust for slightly faster timing,
otherwise forecast remains on track.
A flat, nearly zonal flow across the eastern two thirds of the
country will send several weak disturbances into the area
through early next week. The first of which will pass to the
south of the area tonight with some light rain. The rain will
develop across western locations for mid evening, then
overspread Long Island and possibly SW CT a couple of hours
later. There looks to be a tight gradient from SW to NE, with
the highest chance of rain being across NE NJ, NYC and western
LI. Where it does rain, amounts will generally be less than a
tenth of an inch. Any lingering light rain, exits eastern LI
before daybreak.
Overnight low with the cloud cover and weak warm advection, will
average 7 to 10 degrees above normal. Stayed a bit above the MOS
and NBM.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
Weak high pressure builds across the area on Sunday with another
mild day with highs in the upper 50s to lower 60s. Expect sunny
conditions ahead of the next system`s clouds which will move in
during the evening hours. Rain overspreads area the Monday
morning, prior to daybreak, for all but far eastern LI and SE
CT. This time around there is bit more forcing with jet dynamics
to the north and good frontogenetic forcing just north of the
frontal boundary. This looks to place the forecast area on the
northern edge of the rain, with the potential for a 0.25 to 0.50
inches. The best chance for rain will be across NE NJ, NYC, and
LI. Any subtle north-south shifts will be impactful to how much
rain the area gets. This too will be a fast system, with much
of the rain ending by early afternoon.
Temperatures will remain above normal Sunday night due to the
cloud cover, but with the easterly flow and rain Monday,
temperatures will budge little. Highs Monday will be around 50,
which is several degrees below normal.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
*LONG WAVE PATTERN*
A strong positive height anomaly builds across Davis Strait / So.
Greenland to begin the period. This will force energy ejecting out
of the SW and Lower Plains to drive ENE and eventually merge with
northern branch energy. This will lead to low pressure getting
better organized during Tuesday over the Ohio Valley along a stalled
frontal boundary to the south. Height falls will increase late
Tuesday night into Wednesday leading to low pressure intensifying
and moving through during mid week. The system closes off and may
eventually cut off from the westerlies offshore or nearby late in
the week. This will likely slow the advancement of building heights
over the center of the country into our area towards next weekend.
*DETAILS*
For the first half of Monday night some sfc ridging attempts to get
in momentarily. This will help keep the lower levels dry for a short
while before warm advection off to the west breaks out in the Ohio
Valley and Western PA. This will approach late at night and into the
pre-dawn hours on Tuesday. Thus, rain should break out from WSW to
ENE early in the day Tuesday. This light to moderate rain breaks out
well in advance of the 850 mb warm front via strong WSW flow aloft.
A steadier rain is likely for Tuesday afternoon as strong mid level
forcing pushes in. The primary low drives up into the Great Lakes
and occludes Tuesday night. With weaker forcing at this point it
appears that the rain could very well lighten somewhat Tuesday night.
Upper level energy getting involved via the northern branch of the
jet then leads to cyclogenesis, likely in the Piedmont or just east
of the Central Appalachians. The low will then deepen as it gets off
the coast into the day Wednesday as the 500 mb height minima
approaches. This should lead to an invigoration of precip. As the
column cools look for rain to mix with some wet snow across northern
and northwestern portions of the area. This will be more likely
across the higher terrain of the interior late in the day Wednesday
and into the first half of Wednesday night. Otherwise, look for an
all rain event, especially along and closer to the coast. With the
mid and upper levels becoming less stable with the cold pool aloft
cannot rule out some rumbles of thunder, thus including a slight
chance of thunder during the day Wednesday. Most of the rain from
this event will fall during the day Tuesday - and - during the day
Wednesday. The precip should then become more intermittent and
showery in nature Wednesday night into Thursday morning as the low
gets further north and northeast. Liquid precip amounts will be on
the order of an inch, perhaps as high as an inch and a half. The
hourly rainfall rates are not expected to exceed more than a quarter
inch at any point. However, with soil moisture continuing to run
anomalously high at 100 to 120 percent of normal and the ground
essentially saturated WPC has a marginal risk of flooding Tuesday
into Wednesday. On Thursday with the low just about vertically
stacked and more barotropic in nature, look for an ongoing chance of
hit and miss showers. Some wet snow flakes may mix with the shower
activity, especially across the interior. FOr now have carried
minimal PoPs into Thursday night.
Temperatures for Tuesday through Thursday night should average below
normal. Most of this contribution will be from below normal daytime
temperatures due to increased cloud cover and an onshore flow,
followed by a brisk northerly flow once low pressure gets northeast
later in the week.
Questions remain later in the period as to the degree of blocking up
north potentially maintaining and keeping progression of the
longwave pattern quite minimal for late in the week. The most likely
scenario indicated by global NWP consensus is for the upper level
low to remain relatively close to the area with the degree of
movement to the northeast uncertain. The area will likely be west
and south of the upper level low center Friday into Saturday. This
should keep the area relatively dry, but with plenty of diurnally
driven cloud cover with less stability further up in the column due
to the proximity of the upper level low as lower heights linger.
Temperatures for Friday and Saturday will likely average a few
degrees below normal. If daytime cloud cover is a little less than
anticipated, temperatures could end up closer to seasonable. Night
time temperatures late in the week are expected to be a few degrees
below normal.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
A weak frontal system passes south of the terminals tonight.
High pressure then follows on Sunday.
Mainly VFR. Light rain will develop this evening and continue
through around 04-05z, mainly for NYC metro and western Long
Island terminals as well as KHPN and KBDR. There is chance for
brief MVFR ceilings 025-030 in the light rain mainly from
02-06z. Otherwise, VFR expected on Sunday.
W flow weakens this evening with wind speeds likely 10 kt or
less by 01z. The flow then lightens further through 04z,
potentially becoming variable before shifting to the NW early
Sunday morning. Increasing NW flow after 12z becomes WNW-W
Sunday afternoon, 10-15 kt. Occasional gusts up to 20 kt are
possible late morning into the afternoon.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Light rain may take an hour or two longer to develop this
evening.
MVFR ceilings/visibilities possible 02-06z.
Occasional gusts up to 20 kt possible on Sunday.
OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
Sunday Night: VFR early, then MVFR and rain possible late.
Monday: MVFR-IFR in rain, especially in the morning and early
afternoon.
Tuesday: IFR in rain. E-ENE gusts 20-25 kt.
Wednesday: IFR in rain. E-NE gusts 25-35 kt possible. The rain could
be mixed with wet snow well inland late.
Thursday: MVFR or lower with showers possible, possibly mixed with
snow inland. NW gusts 25-35 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
The small craft advisory has been discontinued, otherwise a few
occasional nearshore gusts up to 25 kt for the next couple of
hours will be possible along the coastline. Otherwise winds
continue to gradually decrease through the night as seas across
the eastern ocean also gradually come down a bit.
Winds and seas should remain below SCA levels through Monday
night. Winds and seas increase Tuesday leading to small craft
conditions developing from south to north across the waters.
Gales then develop on the ocean as early as Tuesday night, and
the eastern non-ocean waters Wednesday. Ocean seas get to 6 and
7 ft Tuesday night, and potentially as high as 8 ft for the
eastern ocean Wednesday. Small craft conditions will be more
likely for the western waters Wednesday night, with gale
conditions perhaps lingering for the eastern most waters
Wednesday night into Thursday.-- End Changed Discussion --
&&
.HYDROLOGY...
Liquid precip amounts are expected to range from an inch to an inch
and a half for the middle of the week. At this time it appears that
hydrologic impacts will be low, however confidence around the
hydrologic response remains lower than average due to completely
of saturated soils and elevated base flows.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...JE/DW
NEAR TERM...JE/DW
SHORT TERM...DW
LONG TERM...JE
AVIATION...DS
MARINE...JE/DW
HYDROLOGY...JE/DW