okx-afd on 2025-03-18

754
FXUS61 KOKX 180809
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
409 AM EDT Tue Mar 18 2025

.SYNOPSIS...
-- Changed Discussion --High pressure builds across today and settles over the region
through mid week. A frontal system approaches from the west
Thursday, passing through Thursday night as a coastal low
develops along the boundary. The system pulls away Friday as the
low deepens, and high pressure briefly returns into Saturday. A
weak area of low pressure moves through Saturday night, with
another frontal system expected to approach early next week.-- End Changed Discussion --

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --All the mid level energy that brought rain early this week cuts off
and drifts off the eastern seaboard. In its wake an elongated ridge
of high pressure will build into the region today. The ridge will
amplify in the mid levels which will prevent anything in the way of
cloud cover for most of the area. For eastern most sections some
clouds will be around for the first half of the day. Otherwise,
expect plenty of sunshine with a northerly flow which advects in dry
air. There should be enough of a northerly synoptic flow to minimize
the formation of a sea breeze. Perhaps late in the day the sea
breeze could initiate as the synoptic flow lightens some. Before
then there could be some occasional gusts through midday. Otherwise
the north flow gradually lightens through the afternoon.
Temperatures will average above normal with widespread middle and
upper 50s closer to the coast, with mainly lower and a few middle
60s further west and well inland.

Clear skies and light to calm winds will be the theme tonight. This
should pave the way for chilly conditions with a good radiational
cooling set up. Lows will range from near to just below freezing in
the coolest spots and mainly 30s, with some lower and middle 40s in
the more urban areas.-- End Changed Discussion --

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --Deep layer ridging will be over the area with sfc high pressure
directly overhead. With the lack of any synoptic flow regime, look
for diurnally driven sea breezes to initiate with daytime heating. A
south to southeast flow will gradually push N and NW through the
area during the afternoon. Max temperatures will be reached earlier
in the day along coastal locations. There will be a large spread in
temperatures by late afternoon with lower and middle 60s further
inland, to near 50 for coastal communities.

For Wednesday night the winds will be light out of the SE. Some of
the soundings are indicating a low level inversion and the
possibility of the formation of low clouds / stratus, especially
further east and south across the area. Have included low end chance
of drizzle for southern portions of the area later at night. Minimum
temperatures will likely range from the middle 30s well inland, to
the lower 40s closer to the coast and in the NYC metro.-- End Changed Discussion --

.LONG TERM /THURSDAY THROUGH MONDAY/...
-- Changed Discussion --Key Points:

* Rain returns late Thursday, with a possible change to snow in some
areas as a frontal wave develops nearby and deepens into Friday

* Gusty NW flow behind the system could exceed 40 mph at times Friday

* Next chance for widespread precipitation then looks to arrive
Monday into Tuesday of next week

Ridging exits offshore to start the period ahead of an amplifying
trough off to the west. Low pressure leading it cuts through the
Great Lakes on Thursday, dragging a cold front toward the area
Thursday night. With increasing southerly flow prior to the arrival,
PWATs climb toward an inch, or around the 90th percentile and the
max moving average for this time of year per SPC. Anticipate a solid
stream of rain along and ahead of the front to move in by the
evening Thursday, persisting overnight into Friday. As the front
moves through, low pressure develops, aided by a southern stream jet
and quickly deepens nearby. This leads to an increasing pressure
gradient late Thursday night into Friday morning and strong NW flow
on the back side of the system could help advect colder air down
enough to allow a quick change from rain to snow early Friday
morning across the interior, and perhaps even down to the coast for
a brief period. A number of factors working against much in the way
of accumulation, though a light accum is possible in the elevated
interior should sufficient rates be realized with soundings hinting
at a saturated DGZ for a period. The deep trough over the Central-
Eastern US moves over the area Friday, leading the surface low to
exit northeast towards the Canadian Maritimes later Friday into
Friday night. Total QPF appears to average around an inch for this
system.

Gusty NW flow Friday with CAA helping deepen the mixing layer. Gusts
could exceed 40 mph into the afternoon before gradually subsiding
into Friday night.

Conditions briefly calm into the start of the weekend as high
pressure returns. Thereafter, a weak disturbance looks to pass thru
late Saturday, perhaps bringing a few rain showers as it does so.
Global guidance continues to advertise a more potent frontal system
approaching from the west early next week, though timing and
placement differences continue to offer a variety of solutions.-- End Changed Discussion --

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --High pressure to the west gradually builds in through the period.

VFR thru the TAF.

NW flow 10 to 15 kt, with gusts 20 to 25 kt thru the morning. Gusts
may hang on til 16Z or so before subsiding, with speeds then
lightening to under 10 kt into late day. Flow goes light and vrb
into the evening with nearby high pressure, and this persists
overnight into Wednesday.

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

No unscheduled amendments expected.

.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...

Tuesday Night through Wednesday: VFR.

Thursday: IFR/LIFR cigs possible in the morning mainly E of the NYC
metros, and MVFR to IFR NYC metros and W. Chance of showers late in
the day, and likely at night, with MVFR to IFR conditions.Snow
showers possible well inland late Thursday night. S winds 10-15 kt
with G20-25 kt, winds shifting W and NW during the evening into the
night.

Friday: MVFR, possibly IFR, with a chance of rain showers along the
coast, and snow/rain showers inland, ending west to east through the
day, and becoming VFR. NW wind 15-25 kt with G30-40kt, diminishing
at night.

Saturday: 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 --Small craft conditions will persist on the ocean waters with
elevated seas as northerly winds gradually come down during the
course of the day. For much of tonight small craft seas of around 5
ft may persist across the central and eastern ocean. Sub small craft
conditions are anticipated on Wednesday as high pressure settles
over the waters with a SE flow developing late in the day and into
Wednesday night.

Ocean seas climb toward 5 or 6 ft Thursday afternoon, before
increasing southerly flow ahead of a frontal system brings SCA
conditions to all remaining waters late Thursday night or Friday
morning as wind gusts exceed 25 kt. Gales possible on all waters
Friday. Ocean seas peak 7 to 9 ft Friday, lowering below 5 ft by
Saturday afternoon, then sub SCA conditions expected on all waters.-- End Changed Discussion --

.HYDROLOGY...
-- Changed Discussion --
No hydrologic impacts are expected throughout the forecast period.-- End Changed Discussion --

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ331-
332-335-338-340-345.
Small Craft Advisory until 6 AM EDT Wednesday for ANZ350-353.
Small Craft Advisory until 6 PM EDT this evening for ANZ355.

SYNOPSIS...JE/DR
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...DR
AVIATION...DR
MARINE...JE/DR
HYDROLOGY...JE/DR