000
FXUS61 KOKX 281139
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
739 AM EDT Mon Aug 28 2023
.SYNOPSIS...
High pressure north of the area slides offshore tonight.
A stationary front slowly lifts north as a warm front tonight into
Tuesday as Tropical Cyclone Franklin remains well offshore. A cold
front moves through on Wednesday. High pressure builds in Thursday
and remains in control into the start of the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Low clouds will hang around through the next few hours with
light and variable winds early this morning. Scattered shower
activity should remain west of the area with a minimal chance
at a few sprinkles or a light shower getting into far western
areas. Have kept PoPs minimal through this morning. No changes
to the current forecast.
High pressure is currently ridging down from the north. Shower
chances will therefore remain minimal today as a result, although
there will be a good deal of cloud cover along with an onshore flow.
Slight chance PoPs only cover a portion of far western Orange County
for today. The clouds will keep temperatures a bit below the
seasonal averages for today. Due to the cloud cover temperatures are
expected to average about 5 degrees or so below average. It will
still remain somewhat humid with dew point reading still mainly in
the middle 60s for today.
Clouds will remain for tonight as shortwave energy and a stationary
boundary off to the south begin to lift closer. Much of tonight
should remain predominantly dry. After 6z precip chances begin to
gradually increase from south to north. Consensus forecasts has the
area remaining dry, especially further north until daybreak. Towards
daybreak the leading edge of convective activity may approach far
southern portions of the area. It will remain seasonable as far as
temperatures go tonight, but it will be continued humid, especially
closer to the coast with an onshore flow bringing in higher dew
points off the ocean.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
The latest CAMs are signaling that convective rain is possible with
the southern edge of the CWA flirting with an area of moderate to
potentially heavy rain through the morning and perhaps up to the
early afternoon on Tuesday. WPC has a sharp cut off in the QPF
amounts which lead to a very deterministic QPF forecast. The
question remains how much of a tropical connection will exist
between Tropical Cyclone Franklin and the stationary / warm front
off to the south, and where does any moderate to heavy rainfall
actually take place. The guidance consensus places the bulk of the
heavy rain along the far eastern and southeastern edge of the CWA.
As a result WPC has placed the eastern half to eastern third of the
area in a marginal risk of excessive rainfall for Tuesday. This
seems reasonable given the uncertainty of where heavy rain may take
place, along with the ingredients being in place, most noticeably
winds below 20 kt through a deep layer through 15 kft, and high PWs
and high mean RH values. Rainfall rates cloud approach an inch per
hour in any robust embedded convection. Have included slight chance
/ isolated t-storm for Tue AM. In any event, much of the guidance is
suggestive of lower rain chances into the afternoon and early
evening as any moisture ahead of the warm front moves northeast with
a break in any rainfall before the cold front draws closer into Tue
night. Therefore later in the day Tue looks to be predominantly dry,
especially further west and northwest.
During Tue night some shortwave energy is progged to push through
early, followed by a cold front approaching which should start to
push through into Wed morning. Around the same time frame Tropical
Cyclone Franklin is expected to lift north in the Western Atlantic
and pass well east of the area during the day Wed as the system is
progged to stay offshore with no direct impacts. However, some
indirect impacts will be dangerous rip currents due to an increasing
swell and high surf, especially out east with regard to the surf.
With an onshore flow it appears that instability will be fairly
minimal, especially at the sfc Tue night. With some elevated
instability pushing through from the west and southwest have
included slight chance thunder. The cold front associated with the
upper trough begins to pivot through into early Wed AM. Did maintain
some continuity with the cold frontal passage with shower chances
and slight chance thunder through much of the day Wed, especially
for the eastern third of the area. Chances for precip does become
quite minimal into the afternoon on Wed, as drier air mass attempts
to nudge in towards evening. With more sunshine overall on Wednesday
temperatures will be closer to normal in the upper 70s and lower 80s.
Monitor https:/www.weather.gov/okx/tropical or http/www.nhc.noaa.gov
for the latest NHC forecasts on this tropical system and others.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A quiet period of weather is expected in the long term. The cold
front should be offshore by the start of Wednesday night and the
upper level shortwave trough axis should also be just to our east.
Thereafter, heights rise aloft and broad high pressure builds in at
the surface over the northeast. The high remains in control through
the weekend and will keep the area dry and mostly sunny.
Stuck close to the NBM through much of the forecast. Made the most
tweaks to Thursday night lows. Given good agreement from the global
models in the placement of the high, light northerly winds across
the interior and clear skies should allow temperatures to drop to
the upper 40s and low 50s. Blended in MEX guidance to capture this.
Winds may stay up too much across Long Island and did not go as low
there.
High temperatures will be about 5-10 degrees below normal on
Thursday, but a gradual warming trend through Sunday is expected.
Sunday will feature highs back in the low to mid 80s. Dewpoints will
also be lowest on Thursday, low 50s, as dry air filters into the
area. With the center of the high sliding east late on Friday the
winds become southerly and dewpoints slowly creep back up.
Tropical cyclone Idalia is forecast to pass to our south and off the
Carolinas Thursday into Friday. The northern edge of the cloud
canopy from this system may lead to more clouds than sun on Friday
but all indications for now is it stays dry this far north.
Monitor https:/www.weather.gov/okx/tropical or http/www.nhc.noaa.gov
for the latest NHC forecasts on this tropical system and others.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
High pressure to our north moves off the New England coast early
today. A weak frontal boundary and wave of low pressure approach
from the south early Tuesday.
MVFR cigs will hang around through the early morning.
Conditions improve to VFR late morning.
A few light showers will be possible at KSWF early today. No impact
to VFR is expected and have left out of the TAF for now with low
confidence of occurrence.
Winds will be light E to SE to light and variable early this
morning, and generally light SE through today under 10 KT.
MVFR to IFR cigs return this evening, spreading from southeast
to northwest through tonight. A batch of rain will approach the
area late tonight. The bulk of the rain looks to just pass to
our south and east. Have only prevailed -SHRA at KJFK for now
out of the 30 hour TAF sites. PROB30 -SHRA at the other NYC
terminals. KGON could go LIFR late in the forecast period in fog
and low stratus and have TEMPOd this.
THE AFTERNOON KJFK HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
THE AFTERNOON KLGA AND KEWR HAZE POTENTIAL FORECAST IS
YELLOW...WHICH IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments may be needed with improvement to VFR this morning
and then again this evening as conditions lower.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday: MVFR or lower in SHRA, mainly KJFK, KISP and KGON.
Wednesday: MVFR possible in the morning in SHRA, otherwise
mainly VFR.
Thursday and Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub small craft conditions take place with mainly 3 ft seas out on
the ocean for today and tonight. An increasing SE / S swell then
sets up with the onset of small craft conditions out on the ocean by
Tue evening. The swell will continue to increase through Tuesday
night, and even more so through the day Wed as ocean seas climb to 5
to 6 ft for much of the ocean waters. Further east out on the ocean
7ft seas are more of a likelihood by late in the day Wed and into
Thu AM. Also by late Wed night and early Thu small craft gusts to 25
kt out on the ocean will be more likely. Also during this time
period, rather energetic S to SE swells will peak at 13 to 14
seconds. Seas are then expected to come down gradually late Thu and
Thu night, with sub small craft conditions possible by late Thu
night and Fri morning. A 9 to 10 second S to SE swell is expected to
linger through a good portion of Friday.
&&
.HYDROLOGY...
There are some indications from some of the higher resolution
convective allowing guidance that there may be a period of heavy
rain for Tuesday morning and early Tuesday afternoon. WPC has put
the eastern half of the area in a marginal risk of excessive
rainfall. At this point in time hydrologic impacts are not
anticipated, but nuisance minor urban and poor drainage flooding can
take place in some locations.
&&
.TIDES/COASTAL FLOODING...
There is a moderate risk for rip current development for all the
beaches today due to a 2-3 ft ESE swell and E winds 10-15kt, then
becoming a high risk on Tuesday as more energetic long period swells
arrive from Tropical Cyclone Franklin.
Swells from Tropical Cyclone Franklin begin to build late today into
Tuesday. This will continue and peak into midweek with 13 to 14
second long period swells from late Tue through Wed night. In
addition, a full moon Wed night will have astro tides increasing
through the mid to late week period. Thus, chances remain high for
high surf and dangerous rip currents through early Thursday.
Combined with the high surf, the potential exists for areas of ocean
beach erosion/flooding and for scattered areas of dune erosion
during the times of high tide Tue/Wed. With respect to coastal
flooding, coastal flood statements have been issued for this
evening`s high tides for the western LI south shore bays of Nassau
and Queens, and for coastal Fairfield, CT. More locations like
Brooklyn and Staten Island may approach minor benchmarks Tue night,
with some gauges in the western LI south shore bays potentially
exceeding minor benchmarks for Tue night. This potential will likely
linger into the Wed and Thu night high tide cycles as well. In
subsequent forecast releases additional coastal flood statements,
along with coastal flood advisories may be needed, especially for
the western LI south shore bays.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/JT
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...JT
AVIATION...JT
MARINE...JE/JT
HYDROLOGY...JE/JT
TIDES/COASTAL FLOODING...