000
FXUS61 KOKX 251642
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1242 PM EDT Thu May 25 2023
.SYNOPSIS...
High pressure builds in from the Great Lakes through the day,
and should remain in control through the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast is on track with only minor changes made for current
observations.
A deep closed upper low will remain fairly stationary over
northern New England this afternoon into tonight, gradually
starting a weakening process. This will anchor troughing across
the NE US, with its associated trough axis approaching the area
this evening and moving overhead tonight. At the surface, a
tight pressure gradient between offshore low pressure and
building high pressure will had a gusty northerly flow across
the region this morning, but is gradually weakening this
afternoon as high pressure builds in.
Scattered afternoon cu developed across interior locations in
the Lower Hudson Valley in a cyclonic flow regime, but has
mostly dissipated in this area. Some clouds will be scattered
to broken across parts of SE CT where clouds have developed and
also far eastern LI has seen some scattered cu. Otherwise,
temps expected to be several degrees below seasonable with caa N
flow (generally mid 60s interior to upper 60s city/coast). The
northerly flow will limit sea breeze development til late day or
evening ahead of weak trough approach, and likely only across
immediate south coastal areas. For now, it looks like this
pattern will mainly occur on far eastern LI, but there is still
a question of how far west the sea breeze may occur.
Surface trough should slide se tonight, with potential for a
period of strong radiational cooling outside of shortwave high
clouds this evening. Lows in the mid to upper 30s likely for far
outlying areas with patchy frost development in coldest spots.
Not enough confidence in widespread coverage of these temps for
frost advisory issuance. Meanwhile temps should hold in the 40s
elsewhere along the coast (lower 50s for NYC/NJ metro).-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Continental omega blocking appears to transition to rex blocking
during this period. New England closed upper low gradually
shears ne thru the Canadian Maritimes Fri into Fri Night, with
ridging surface/aloft building across the Great lakes into NE US
this weekend. This setup, will keep a developing cutoff upper
low and coastal low across the SE US/Tennessee Valley states
this weekend.
Canadian high pressure will dominate our weather pattern through
this period with tranquil and gradually moderating conditions.
Increasing high clouds possible Sunday as the closed SE low tries to
drift ne. Wind direction will be a bit tricky Sat/Sun period based
on exact location of a couple of meso highs across the region.
General theme will be a weak synoptic flow, giving way to S/SE
coastal sea breeze development each day. The sea breeze could be
progressively stronger each day based on increasing land/sea
temp gradient.
With plenty of sunshine, moderating airmass, and deep mixing
each day, temps should warm up quickly each morning/early afternoon
before halting/dropping after sea breeze frontal passage across
the coastal plain each afternoon. Highs will moderate to near
seasonable levels on Friday, and then progressively warmer each
day. Areas well N&W of the NYC/NJ metro will have the warmest
temps with temps flirting with 80 degrees by Sun. Meanwhile
closer to the coast, temps should be limited to the lower 70s-75
with sea breeze development, likely holding in the 60s along
the immediate ocean shoreline. Have blended NBM deterministic
with NBM 50th percentile thru this period, as deterministic lies
near the 25th percentile of NBM ensemble (particularly for the
coast). This may be too low based on the typical quick warming
along the coast in the weak flow regimes before sea breeze
development.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A blocking pattern will persist late this weekend into at least
the middle of next week. A large ridge is progged to be
situated over much of CONUS with high pressure dominating at the
surface through the period. Cutoff low under the ridge will
slowly push off the Carolina coast early next week. The overall
synoptic pattern favors any low pressure and associated precip
remaining well to the south and east of the region. The 00z
model suite indicates another upper low may sink south into the
Maritimes early next week as well, which may lower
heights/weaken the ridge just a bit over the northeast. This may
send a backdoor cold front towards the area. However,
confidence is low that it would fully make it through the
region. The axis of the ridge may then shift westward for the
middle of next week.
Have gone with a dry forecast Sunday night through Wednesday
based on the ridging aloft and that precip with the low over
the Carolinas will remain well south of the area. The ridging
both at the surface and aloft will prevent northward movement of
the this system. Conditions look to remain dry thereafter
through the middle of next week.
Temperatures for Memorial Day should be above normal in the upper
70s and lower 80s, warmest away from the immediate coast and sea
breezes. Temperatures likely remain above normal into the middle
of the week, but could be slightly cooler on Tuesday due to
more of an easterly flow. This will depend on where the backdoor
front reaches. If it stays northeast, temperatures likely end
up warmer. Have gone with the NBM for now, which indicates highs
in the 70s for most locations on Tuesday.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR. High pressure builds in from the Great Lakes region
through Friday.
NNW-N winds 10-15 kt into the afternoon, diminishing late
afternoon into the evening. A SE sea breeze is expected at KGON
late this afternoon and could also approach KJFK. Have
continued with a TEMPO at KJFK as the sea breeze boundary could
set up near or right over the terminal late this afternoon and
early this evening. Winds diminish this evening, becoming light
and/or variable overnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
End time of gusts may be off by +/- 1-2 hours.
Sea breeze could move through KJFK 21-23z with winds prevailing
out of the SE.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday-Monday: VFR. SE gusts 15-20 kt possible near the coast
on Sunday.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
Sub-SCA winds expected tonight through early next week under a
weak pressure gradient under high pressure. The exception may be
marginal SCA ocean seas developing in a se swell late Saturday
into Sunday morning in response to a long fetch E/SE flow.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the middle of next
week.
&&
.TIDES/COASTAL FLOODING...
Our surf zone forecast program starts this afternoon.
There is potential for a moderate risk of rip currents Saturday
through Monday. The risk may be high late Saturday into Sunday
as SE swells build to 4 ft.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/NV
NEAR TERM...BR/NV
SHORT TERM...NV
LONG TERM...DS
AVIATION...IRD
MARINE...DS/NV
HYDROLOGY...DS/NV
TIDES/COASTAL FLOODING...