000
FXUS61 KOKX 281516
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1116 AM EDT Sun May 28 2023
.SYNOPSIS...
-- Changed Discussion --
High pressure will be in control through today. A backdoor cold
front moves through Memorial Day. High pressure then dominates
through the upcoming week, with weakening southern low pressure
tracking south of the region. A cold front approaches Friday
and passes though late Friday. Canadian high pressure builds
back into the region for next weekend.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --
Updated for winds, temperatures, dew points, and sky cover. Sea
breezes wee already moving into the coastal locations, and
updated mainly for those areas. Also with the cirrus shield
south of the region, associated with low pressure over the
southeastern states, reduced sky cover across much of the
region, especially inland.
A blocking upper high will remain from the Great Lakes into the
northeast through Memorial Day, while an upper low meanders
over the southeastern states. The center of surface high
pressure will be situated southeast of the area today allowing
southerly flow to continue through the day. A shortwave will
pass across southeastern Canada and the Maritimes tonight
helping to push a backdoor cold front through the area on
Monday. High pressure will otherwise be in control of the
weather.
The backdoor cold front moves through Monday afternoon. The
front will move through the region dry, but shift winds to the E
and then NE late. Temperatures should still be able to warm
into the 70s for most and lower 80s across the Lower Hudson
Valley and northeastern New Jersey. The E flow increases in the
afternoon as the front moves through bringing a shot of cold
advection. Temperatures will begin to fall into the 60s in the
mid to late afternoon across Long Island and southern
Connecticut and then start reaching the rest of the area in the
early evening. E-NE winds 10-15 mph with gusts 20-25 mph are
expected, strongest near the coast late in the day.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A reinforcing high pressure builds over New England Monday
night, remaining nearly stationary on Tuesday. The high weakens
a bit on Wednesday, but will still dominate the surface
pattern. Not much change is anticipated aloft with the blocking
upper high remaining in place over the northeast. The upper low
over the southeast may slowly lift towards the Middle Atlantic
coast into the midweek. However, the upper ridging will continue
to provide subsidence and keep any precipitation to our south.
Breezy conditions will continue Monday night, especially near
the coast. Lows will fall into the middle and upper 40s inland
and lower to middle 50s near the coast. Highs on Tuesday will
likely end up slightly below normal with continued E flow. Highs
will range from the upper 60s (coast) to middle 70s (well NW of
NYC metro). Cool conditions are expected again on Tuesday night
similar to those forecast on Monday night. Moderating
temperatures likely occur on Wednesday as the E flow is much
weaker and gradually becomes SE in the afternoon. Highs will
range from the lower to middle 70s south to upper 70s and low
80s north.
Some cirrus clouds are likely to move overhead as the aforementioned
upper low starts to reach the Middle Atlantic. These clouds should
not impact sky conditions much with mostly sunny skies both
Tuesday and Wednesday.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
Persistent ridging surface/aloft breaks down midweek, allowing
the filling southern US closed low to drift northeast towards
the area Wed/Thu. Models have trended a bit slower and farther
north with this low, eventually shearing it east and offshore
Friday ahead of a strengthening SE Canada upper low drifting
south. Troughing around the northern upper low will exert its
influence on the NE US heading into the weekend.
Surface high pressure continues to weaken Wednesday into
Wednesday Night, while the weakening southeastern low drifts NE
off the Mid Atlantic coast. Its precip shield will get close as
the low passes just to the south, with a low probability of
skirting southern portions of the area Wed NIght into Thu. There
has been a slower and farther northward trend with this low
over the last 48 hours, so will have to see if POPs trend upward
a bit for Wed Night/Thu. Accordingly, temps will be a bit
tricky Thu, based on evolution of the shearing low and amount of
associated high/mid clouds. Have stayed close to NBM
deterministic based on this uncertainty, although noted that
deterministic is running between the 10th and 25th percentile of
NBM ensemble spread. With WNW flow aloft advecting in a very
warm airmass (building across Ontario and Quebec midweek) ahead
of an approaching cold front, this still presents very warm
conditions across the area (upper 80s to around 90s for NYC/NJ
metro and point N&W to upper 70s/lower 80s for the coast) . The
weak flow, leading to progressive afternoon seabreeze
development, along with potential cloud cover, would limit
potential to reach the max temp potential of lower to mid 90s
across interior and well into the 80s for the coast signaled by
the NBM ensemble 50th percentile.
Greatest potential for hot and dry conditions appears to be
Friday with continued W/NW flow aloft advecting in 850hpa temps
of 16-17C, downslope flow, and deep mixing above 850mb. Timing
of cold front passage is one caveat, although medium range
guidance has trended slower with this, more towards evening. NBM
deterministic is currently running at or below the NBM ensemble
10th percentile, which is still lower 90s NYC/NJ metro and
interior and well into the 80s for the coast (about 15 degrees
above seasonable). Have blended NBM deterministic with NBM
ensemble 50th percentile based on ideal downslope heating setup,
which may still be too conservative based on NBM deterministic
performance in these events. Potential for forecast high temps
to trend into the lower to mid 90s across NYC/NJ metro and
interior, and upper 80s to lower 90s for much of the coast if
the downslope set-up become realized. Heat indices will likely
be at or below ambient temps due to the dry airmass.
The cold front passes through sometime Friday eve, although
timing is still uncertain. Moisture and forcing will be limited
in NW flow regime, which should limit shower/tstm activity to
isolated at best with passage.
Canadian maritime high pressure builds towards the area Friday
Night into Saturday with gradual caa and dry conditions, but
temps still likely running a few degrees above seasonable in the
upper 70s to lower 80s Saturday. Canadian maritime airmass may
become more entrenched Sunday, with continued dry conditions but
temps falling to near seasonable.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
High pressure weakens as it continues to track offshore through
tonight. A backdoor cold front will then move across the area
Monday morning into early afternoon.
VFR conditions. Light S/SW flow becomes S/SSE 10-15kt with
seabreeze development. S winds diminish during the evening,
becoming light and variable tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of seabreeze could be off by an hour or so.
There is a low chance for a few gusts to 20 kt at KJFK/KLGA in
the late afternoon.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Monday: VFR. Light NE winds for early AM push, then fropa with
E winds 15G20-25kt during the late morning. Fropa could be as
early as tail end of morning push.
Tuesday through Thursday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Cold water headlines continue through the holiday weekend for
cold water immersion threat from sub 60 degrees waters.
No changes to the winds and seas at this time.
A relatively weak pressure gradient this weekend will keep
conditions below SCA levels through Sunday night.
Winds may approach 25 kt Monday afternoon and evening on the
ocean, LI Bays and eastern LI sound as a backdoor cold front
moves through. Ocean seas may also reach 5 ft late Monday
afternoon into Monday night. Have held off on an SCA issuance
for now based on collaboration with neighboring offices. The
gradient relaxes by Tuesday morning with sub SCA conditions
continue through the end of the week. Persistent SE swells
gradually subside middle to late week.-- End Changed Discussion --
&&
.HYDROLOGY...
The prolonged stretch of dry weather continues through the
upcoming week.
&&
.TIDES/COASTAL FLOODING...
A moderate risk of rip current development at Atlantic Ocean
beaches continues today with 3ft@7-8 second SE swells today.
An increasing E flow Monday may bring seas close to 5 ft late
Monday afternoon. A moderate risk of rip current development
continues, but a high risk may be needed for Monday afternoon if
the seas build several hours faster than currently expected.
Rip current activity will likely be enhanced in vicinity of groins,
jetties, and piers through this period with E to W longshore
current.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DS/MET/NV
NEAR TERM...DS/MET
SHORT TERM...DS
LONG TERM...NV
AVIATION...NV/DW
MARINE...DS/MET/NV
HYDROLOGY...DS/NV
TIDES/COASTAL FLOODING...