485
FXUS61 KOKX 310227
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1027 PM EDT Fri Aug 30 2024
.SYNOPSIS...
-- Changed Discussion --
High pressure retreats to the northeast overnight as a warm
front approaches late tonight into Saturday. A cold front pivots
through late Saturday night into Sunday. A secondary cold front
moves through late Sunday into Sunday night. Thereafter, high
pressure builds in from the Great Lakes region and will remain
in control through the middle of next week, gradually moving
offshore late next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Forecast on track as strato cu expands eastward with the
retreating ridge.
High pressure should maintain itself for the most part down the
New England coast and into at least eastern portions of the
area overnight. A warm front back to the west and southwest
will be held back as the surface high and mid to upper level
ridging should keep the region primarily dry through the night.
A fair amount of cloud cover will persist, more so across the
western half of the area initially. Then later tonight as the
high starts to lose its influence more cloud cover overall gets
into eastern portions of the area. A light onshore flow will
continue, thus with the onshore flow and cloud cover this should
put a floor on how much temperatures can drop tonight.
Temperatures should hold near seasonable levels with little
spread, with lows in the 60s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
Whatever is leftover of mid level ridging should hold through
the first half of the day keeping the region dry. A warm front
should be draped across PA and the southern tier of NY during
the morning. The warm front should gradually make its way east
into the afternoon and early evening. Some showers are likely to
develop to the northwest later in the day. Towards evening the
chances of shower activity should increase across NW sections.
Partial sunshine is expected for much of the day, with more
clouds, especially further west in the afternoon. A S to SSE
flow will have dewpoints increase into the middle and upper 60s
adding more humidity. Temperatures will be near seasonable
levels, but becoming more humid with day time highs in the upper
70s to lower 80s. As the area gets into the warm sector
instability begins to increase further west late in the day and
towards evening. PWATs begin to climb above 1.5, and eventually
get closer to 2 inches into the evening. With a more humid
environment the chance of showers increase from west to east out
ahead of a cold front for Saturday evening. Some steadier
rainfall, especially across the western half of the CWA becomes
more likely later Saturday night. Some embedded heavier showers
will be possible with any thunderstorms that form. BUFKIT
soundings for the NAM3km and RAP, GFS are indicating some CAPE
Saturday night. For more rain detains see the hydrology section.
SPC has a marginal to slight risk of severe weather mainly for
the Saturday evening / night period, with the risk decreasing
eastward. A more general thunderstorm category has been placed
across eastern sections. It is likely, at least initially during
Saturday night that the instability will be more elevated, with
more sfc based instability likely waiting until later in the
weekend. The stronger mid level forcing appears to be lagging a
bit back to the west, at least during the first half of Saturday
night.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A well-defined secondary cold front arrives late on Sunday and
manages to push through Sunday evening and early night.
A line of showers and thunderstorms will pass along and ahead of the
front, clearing out early Sunday night. Sufficient moisture (max
PWATs around 2 inches), warm temperatures (highs in the low/mid-
80s), and ample instability (SBCAPE peaking around 1000-2000 J/kg)
will allow for a good environment for thunderstorms that could lead
to an occasional downpour. However, bulk shear appears to be lacking
with peak values around (20-30 kt), so the only concern severe
weather concern may be an isolated instance or two of strong to
damaging winds along the cold front where the greatest amount of
forcing and lift will be present. SPC has highlighted a Marginal
Risk for the area on Sunday.
Following the cold front Sunday evening/night, winds will turn from
south to northwest, advecting cooler, drier air into the area.
Dewpoints will drop through Sunday night and continue to do so
through the day on Monday. With strong cold air advection aloft at
850 mb and a steady northwest wind, highs on Monday will be limited
to the low/mid-70s with a few reach the upper-70s.
High pressure will continue to build in behind the exiting front
from the Great Lakes region on Monday and Tuesday, leaving a very
sunny forecast for early next week. Overnight lows will drop into
the upper-40s to upper-50s north-to-south Monday night. Dewpoints
drop into the 40s Monday night and remain there through Tuesday
night, reinforced by northwest flow. This will lead to conditions
feeling cool and crisp during the nights and pleasant in the
afternoons with highs in the mid/low-70s on Tuesday.
Most model guidance brings the high pressure overhead on Wednesday,
then gradually push it offshore Thursday and Friday. This will lead
to a return flow from the southerly. High pressure will firmly
remain in place on Wednesday and still mainly in control on
Thursday, allowing for more cloud-free days, before cloud cover
increases as the high exits east Thursday night into Friday.
Southerly winds will lead to increasing temperatures and dewpoints
late next week. HIghs will be in the mid-70s to low-80s by Friday.
Most global models try to develop a coastal low along the mid-
Atlantic coast Friday and bring it near the CWA Friday night into
Saturday, but this is still very far out and the models do differ in
strength, placement, and timing.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
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High pressure remains across the area, weakening overnight. A
warm front approaches Saturday and moves through the area
Saturday night.
VFR, then becoming MVFR overnight, after 05Z, with local IFR
possible toward Saturday morning. A few locations were already
developing high end MVFR ceilings at 02Z. Confidence is low with
the timing of MVFR ceilings overnight. VFR returns late
Saturday morning into early afternoon.
Light easterly winds become light and variable at the outlying
terminals. Winds become southerly Saturday morning. Moderate
confidence on the wind forecast.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Time for MVFR ceilings overnight may be off by a couple of
hours, as will be the return to VFR Saturday morning.
OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday PM: VFR. Iso tstm with brief MVFR possible NW of the
city early evening. Then MVFR to IFR in showers with an iso tstm
possible.
Sunday: MVFR/IFR with a chance of showers in the morning. VFR
in the afternoon with iso shower/tstm possible.
Monday through Wednesday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and waves will remain below SCA criteria through Saturday
night, and also should remain below SCA criteria through the
middle of next week. There could be a period of occasional 25 kt
gusts this weekend and on Monday with two cold frontal
passages, but this remains a low probability at this time.
&&
.HYDROLOGY...
Any hydro related impacts over the weekend appear fairly minimal at
this time. There remains the possibility of minor flooding in poor
urban drainage locations with any heavier showers across mainly
for the western half of the CWA towards Saturday night. WPC
maintains a marginal risk of excessive rainfall across a good portion
of the CWA.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
There is a moderate risk for rip currents along NYC and Nassau
county beaches on Saturday. All Long Island ocean beaches will have
a low risk for rip currents on Sunday.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/BR
NEAR TERM...JE/BR/MET
SHORT TERM...JE
LONG TERM...JC
AVIATION...MET
MARINE...JE/BR/MET
HYDROLOGY...JE/BR
TIDES/COASTAL FLOODING...