okx-afd on 2024-08-29

821
FXUS61 KOKX 291913
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
313 PM EDT Thu Aug 29 2024

.SYNOPSIS...
-- Changed Discussion --High pressure to our north shifts east tonight with a lingering
surface ridge into Friday night. A warm front moves through on
Saturday and then is quickly followed by a cold frontal passage
Saturday night. A secondary cold front moves through late Sunday
into Sunday night. Thereafter, Canadian high pressure builds in
and will remain in control through at least the middle of next
week.-- End Changed Discussion --

.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --High pressure to our north shifts east tonight. It brings a short
wave ridge at the surface and lingers it over the area through
Friday. To the west, a small shortwave trough embedded within a
longwave ridge aloft brings positive vorticity advection aloft
tonight into tomorrow.

With ample moisture in place, this could lead to the development of
isolated to scattered showers tonight into the day tomorrow. Most
CAMs agree on scattered showers tonight in the Hudson Valley, SW CT
and NYC metro, then taper those chances eastward. These will
originate from a line of showers and thunderstorms that are
currently developing across central Pennsylvania. There is much
disagreement among the CAMs on the extent of shower coverage and
timing tomorrow during the day. Have gone with slight chance for
much of the area tomorrow, opting to only go chance for far west and
southwestern areas where there is somewhat more agreement on placing
of showers. Instability will be low, so any chances of thunder have
been dropped out of the forecast for tonight and tomorrow. Overall,
the POP forecast is low confidence and may be followed by
adjustments as confidence increases.

Temperatures will remain mild tonight in the low/mid-60s with
dewpoints lower near 60. Tomorrow will see plenty of cloud cover
with mild highs in the low/mid-70s, a few degrees cooler than
observed on on Thursday.-- End Changed Discussion --

.SHORT TERM /FRIDAY NIGHT/...
-- Changed Discussion --A small shortwave trough aloft exits east Friday night along with a
surface ridge. This will lead to tapering showers, which will lead
to dry conditions prior to sunrise and around daybreak on Saturday.
Saturday night will remain mostly cloudy-to-overcast with lows in
the low-to-upper-60s.+-- End Changed Discussion --

.LONG TERM /SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --Bit of a tricky PoP forecast to start on Saturday. A lingering
surface ridge will be extended into the area from departing offshore
high pressure. Aloft, shortwave ridging will also be moving through.
The surface ridge from the offshore high looks to hold off the warm
front early Saturday, but if the ridge breaks down earlier, the warm
front may be able to advance faster. If this happens, rain showers
will be possible earlier than the current forecast shows for
Saturday morning.

Most of the action for the weekend looks to come Saturday evening
and overnight ahead of and along a cold front. This timing continues
to be favorable for us, as instability will be lower overnight due
to the loss of daytime heating. However, pwats in the latest NAM and
GFS are both still around 2 inches right ahead of the cold front.
So, any showers or thunderstorms that move through have the
potential for heavy downpours. The bulk of the showers and
thunderstorms will be done Sunday morning, but a secondary cold
front moves through, so PoPs linger into Sunday evening.

Thereafter, Canadian high pressure builds into the area and brings a
cool and dry airmass to the region, with sunny conditions. On
Monday, dewpoints drop into the 40s and will stay there through
midweek. Temperatures will be below normal for early September
during most of next week.-- End Changed Discussion --

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
High pressure across eastern Canada will continue to build
southeast into the area into Friday.

Primarily VFR conditions are expected into the evening, although
can`t rule out periods of MVFR ceilings at all terminals. MVFR
conditions are then expected to prevail for city and western
terminals after 06Z in showers. Eastern terminals should remain
dry due to the building high along the New England coast,
although a period of MVFR ceilings may be possible after 12Z.
Forecast uncertainty then increases Friday afternoon, with the
potential for another round of showers.

E-SE winds around 10 kt this afternoon will gradually diminish
this evening. E-SE winds will continue on Friday.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Low confidence in the timing and duration of showers and MVFR
conditions overnight into Friday morning.

OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...

Friday afternoon: Becoming VFR. Chance of showers at city and
western terminals.

Saturday: VFR. MVFR or lower possible in showers and
thunderstorms during the evening and overnight.

Sunday: Mainly VFR. Chance of showers, mainly in the morning.

Monday and Tuesday: VFR.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

.MARINE...
-- Changed Discussion --Winds and waves will remain below SCA criteria this week,
weekend, and 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.-- End Changed Discussion --

.HYDROLOGY...
Any hydro impacts over the weekend appear minimal at this time.

.TIDES/COASTAL FLOODING...
-- Changed Discussion --The moderate risk of rip currents continues on Friday, with the
easterly flow continuing, but closer to 12 to 14 knots. Given the
easterly flow, rip current activity will be enhanced along jetties
and groins.

On Saturday, the flow becomes southerly, just under 10 knots. 1 ft
long period southeasterly swell does build into the area, but
thinking low risk of rip currents for now with RCMOS showing
lowering probabilities into Saturday.-- End Changed Discussion --

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

SYNOPSIS...BR/JT
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...JT
AVIATION...FEB
MARINE...BR/JT
HYDROLOGY...BR/JT
TIDES/COASTAL FLOODING...