889
FXUS61 KOKX 222016
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
416 PM EDT Sat Mar 22 2025
.SYNOPSIS...
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A cold front moves across this evening. High pressure builds in
for Sunday. A frontal system moves across Sunday night into
Monday. Weakening low pressure will track across southeastern
Canada Monday night into Tuesday night, with another weak low
passing to the south late Tuesday night into Wednesday. High
pressure then builds in to the south for the end of the week. A
frontal system may impact the region Saturday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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500mb trough continues to approach from the west late this
afternoon. Southerly flow advecting in warmer air.
Surface pre-frontal trough moves across late this afternoon,
with more westerly component in winds after its passage. Farther
west a cold front will be approaching with associated parent
low well within Southeast Canada moving northward in Quebec.
Actual observed Doppler radar reflectivity indicates echoes of 10 to
30 dBZ range traversing the region but dry low levels preventing
rain from reaching the surface. More rain showers expected
towards the evening.
BUFKIT models show late day mixing when winds veer to more WSW. The
high temperature could very well get achieved late in the afternoon
with this westerly flow adiabatic mixing down to the surface.
For tonight, mid level trough moves across with cold front
moving across. This will be during the evening hours. Showers
early then dry late evening and overnight. Cold air advection
late evening and for rest of tonight with NW gusty winds.
500mb trough axis moves across this evening. This moves east of the
area thereafter through the rest of tonight. Region remains in 500mb
NW flow. Some positive vorticity advection in the mid levels along
with coherent discrete echo reflectivity within mesoscale models
from multiple model runs so chance POPs for entire region and
some likely POPs mainly for Orange County before 8PM. Narrowed
the chance POPs to occur mainly 6-10PM.
Cold front moves across this evening generally between 8 and 11PM.
Cold front expected to be southeast of Long Island after 11PM
and then the front will continue moving out into the Atlantic
overnight. Winds at the surface transition from gusty WSW ahead
of the cold front to more gusty NW flow behind the cold front.
Dry and cold air advection then increase.
Models indicate a significant 850 mb temperature decrease of around
6 to 7 degrees C between 8PM tonight and 2AM Sunday. 850mb
temperatures thereafter going into early Sunday morning rise
slightly for western half of the forecast region and remain
nearly constant for eastern half of the forecast region.
With the gusty winds, expect a less vast range of low temperatures.
The lows will only vary from mainly the mid 20s for much of the
interior to the lower 30s along the coast. This used a blend of
MAV/MET/consensus of raw model data with slight adjustments up near
Westhampton NY.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
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Brief mid level ridging Sunday and surface high pressure moving
across will maintain dry conditions during the day. NW flow remains
gusty to start the day but will decrease during the day as the
pressure gradient weakens.
Models convey warmer air advecting in at 850mb. This will set up an
inversion. Less vertical mixing is expected especially as winds
become lighter. The max temperatures forecast Sunday are expected to
be around 10 degrees cooler than the previous day max
temperatures. Used the NBM for high temperature forecast.
Also mitigating the high temperature will be increasing clouds
during the day as the high pressure will be relatively weak.
Upstream higher level clouds will expand and move into the local
region for the afternoon but still expect substantial sunshine
overall.
Incoming mid level trough for Sunday night with closed off low
moving east within Great Lakes. At the surface, there will be a
surface low moving eastward through the Great Lakes. An
associated warm front approaches from the south and west.
Strong mid level shortwave moves across early Monday and then east
of the region Monday afternoon. However, overall in the larger
scale, region remains in the longer wavelength trough with that
closed low moving into SE Canada, near Ontario and Quebec border.
At the surface, warm front slows down as it moves across with a
weak low pressure area developing along it. The low pressure
makes its way across the area Monday afternoon with a cold front
to the south of it. Surface winds go from southerly Sunday
night into early Monday to more southwesterly Monday afternoon.
Surface and low level winds become more southerly Sunday evening
across the region. These winds will increase Sunday night into
Monday morning. The approaching system low level jet comes
across for early Monday morning.
Low level warm air advection expected Sunday night into Monday.
Precipitation returns, more of a stratiform overrunning
rainfall. Precipitation starts mainly late evening Sunday
night. This will be primarily light. Locations within the
northern half of the forecast region are forecast to have enough
wet bulb cooling for a mix of rain and snow with some periods
of all snow before 5AM Monday. Warmer temperatures and boundary
layer along the coast keeps precipitation all rain for southern
half of the forecast region.
As this low level warm air advection increases, more early Monday,
the precipitation forcing increases. This will make for a steadier
rainfall along the coast. Bulk of the rain is expected early Monday,
with rain being the dominant weather feature Monday morning. Some
interior locations will have a wintry mix, around 5AM to 10AM
Monday but those locations are also expected to warm up enough
to make for all rain by late Monday morning. Frontal system
precipitation closes out late Monday morning through Monday
afternoon with rain. Rain likely lingers across Southern CT and
Long Island late afternoon into early Monday evening with
lesser chances of rain to the west across the rest of the
forecast region.
Any snow for the event confined to the interior with potential
for near 1 inch or less of snow. Any ice accumulation just
potential to be a glaze. Uncertainty with low level warm layer
at 850mb early Monday, NAM higher temperature, GFS less
temperature. Used a blend with thicknesses for that
precipitation type forecast.-- End Changed Discussion --
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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No significant changes to the extended with this update as generally
quiet weather persists through the period. And with no significant
variance in the guidance, and targets of opportunity, mainly used
the NBM deterministic guidance. However, for the possibility of
windier conditions Monday night into Tuesday, and Wednesday night
into Thursday, leaned toward the higher 75th and 90th percentiles
for winds and gusts. Temperatures will be generally near normal,
with slightly above normal lows Monday night, and with the approach
of a warm front late in the week, temperatures may be 5 to near 10
degrees above normal Thursday night into Saturday. Although there
is uncertainty as to where the warm front will set up by late in
the week as the associated low will be over the plain states.
A upper level high amplitude longwave trough will be over the
eastern states Monday night into Wednesday night with a high
amplitude ridge over the western states. The trough begins to move
offshore late Wednesday night as heights rise Wednesday night into
Saturday as the upper ridge moves slowly eastward, and gradually
weakens next Saturday.
Late Tuesday night through Wednesday there is a chance of
precipitation as energy moves into the base of the upper trough, and
surface low pressure passes to the south. Any precipitation will be
light, with rain along the coast, and snow inland. Then dry weather
is expected Wednesday night into next Saturday as the ridge and
surface high pressure dominate. And the next chance of precipitation
will be later Saturday with a warm front, and forcing along this
boundary. Although there is uncertainty as to where this will set
up with the surface low well to the west.-- End Changed Discussion --
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A cold front passes through this evening.
VFR. Mainly SW-WSW winds with gusts around 25kt this afternoon.
Winds shift NW and increase by a few kt this evening. Winds then
diminish late tonight and through the day Sunday.
PROB30 for showers with brief MVFR vsbys for all but KISP and KGON
late day/early evening. Any showers before around 23z likely would
not cause vsby restrictions.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
A brief shower will be possible as early as 19z, but likely would
not cause vsby restrictions before 23z.
Chance that conds remain VFR in in any shower. PROB30 timing and
subsequent wind shift to NW may be off by an hour.
.OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
Sunday aftn/eve: VFR.
Late Sunday Night and Monday: Becoming IFR with rain. Possible onset
as snow for KSWF. S winds G15-25kt, strongest near the coast on
Monday.
Tuesday: VFR. WSW winds G20 kt possible.
Wednesday: MVFR possible. Chance of showers.
Thursday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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Small craft advisories, SCAs, are in effect for the ocean and
stay in effect through Sunday morning. Some lingering SCA ocean
seas and some lingering SCA wind gusts Sunday afternoon east of
Fire Island Inlet, so that segment SCA goes until 3PM Sunday.
Non-ocean waters have SCA in effect from 8PM tonight until 9AM
Sunday and then all non-ocean marine zones except for NY Harbor
and Western LI Sound go until 12PM Sunday for their SCA.
Brief sub-SCA conditions forecast for the waters Sunday
afternoon for most waters, after 3PM Sunday afternoon, east of
Fire Island Inlet on the ocean and that continues through much
of Sunday night. However, SCA potential increases late Sunday
night for parts of the ocean. Most waters in SCA range for wind
gusts Monday. Ocean seas rise back to 5 to 7 ft late Sunday
night into Monday.
Small craft advisory level ocean seas will likely continue Monday
night into Tuesday evening with a weakening southwest flow. Then
winds and seas will be below advisory levels across the forecast
waters Tuesday night through Thursday. With an increasing southwest
flow late Thursday night ocean seas may build to near 5 feet.-- End Changed Discussion --
&&
.HYDROLOGY...
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Low pressure system tonight, less than a tenth of an inch of
rain.
Low pressure system late Sunday night through Monday evening,
around 0.25 to 0.5 inch of rain/liquid equivalent.
No hydrologic impacts expected through the end of next week.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 8 PM this evening to noon EDT Sunday
for ANZ331-332-340-345.
Small Craft Advisory from 8 PM this evening to 9 AM EDT Sunday
for ANZ335-338.
Small Craft Advisory until 3 PM EDT Sunday for ANZ350-353.
Small Craft Advisory until noon EDT Sunday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JM/MET
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MET
AVIATION...JC
MARINE...JM/MET
HYDROLOGY...JM/MET