635
FXUS61 KOKX 292346
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
646 PM EST Fri Nov 29 2024
.SYNOPSIS...
The region will remain between broad low pressure over southeast
Canada and and high pressure building into the Mississippi and
Tennessee Valleys into early next week. The high will briefly build
across on Wednesday before low pressure moving from southern Canada
into northern New England brings an associated frontal system across
Wednesday night into early Thursday. The intensifying low will move
into the Canadian Maritimes Thursday night into Friday while strong
high pressure builds into the northern Plains states.
&&
.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --
The forecast remains on track. KOKX 88D showing some isolated
showers/flurries across eastern LI and CT this hour with only
brief rain/snow showers appearing in any surface observations
and mping reports. These should continue to push east, and
weaken over the next hour or so. No accumulation, or impacts,
are anticipated from these rain/snow showers.
A well defined shortwave as seen on GOES-16 Water Vapor Imagery
will continue to move out of the Ohio Valley towards the
northeast through this evening. Fairly steep lapse rates ahead
of the shortwave have led to some isolated sprinkles with some
flurries. There have been some reports of some ice pellets
and/or flurries even down towards the coast. This is likely due
to a very dry subcloud layer allowing for some wet bulbing to
occur, despite surface temperatures in the 40s.
Another round of cold advection kicks in behind the shortwave
tonight, which should lead to clearing skies and drier/colder
air to advect into the area. Lows will fall into the middle and
upper 20s for most locations with readings in the low 30s in the
NYC metro. The forecast low for Central Park is 31 degrees,
which would be the first freeze of fall 2024 and coldest
temperature since March 24th (also a low of 31 degrees and last
time below freezing).
The broad upper trough will remain over the eastern CONUS this
weekend. The flow will predominately be westerly, but there still
may be some energy aloft to support the development of scattered
clouds in the afternoon. There have been some subtle hints on the
CAMs for some flurries in the afternoon. Surface dew points in the
teens and low 20s and a dry subcloud layer should prevent anything
from reaching the ground. Highs will only be in the upper 30s and
low 40s, around ten degrees below normal for the end of November.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
Very little change with the pattern Saturday night through Sunday
night with a broad upper trough overhead. The region will remain
between low pressure over southeast Canada and high pressure to the
south and west.
Meteorological winter 2024-2025 will begin with lows in the
upper teens to low 20s inland and middle to upper 20s
elsewhere. The upper trough may start to amplify late Saturday
night as another shortwave/vortmax moves along the US/Canada
border. Model time height cross-sections indicate a layer of
moisture coming in Sunday morning from around 10 kft to 25 kft.
The NAM and GFS profiles both indicate a layer of higher RH with
respect to ice saturation. The profiles are less saturated
further inland. There is also a sheared out vortmax signaled in
the modeling along with the region lying along the northern
periphery of an upper jet just to the south. Feel it is
reasonable to think sky conditions become mostly cloudy for at
least the southern two thirds of the area Sunday morning as this
moisture moves overhead. Models can struggle with cloud cover
in these scenarios and the latest model consensus keeps skies
mostly sunny to partly cloudy. Have gone ahead and bumped sky
cover up with mostly cloudy conditions in the morning gradually
becoming partly cloudy late in the day. Mostly cloudy conditions
may extend further north than currently forecast if the GFS and
NAM profiles are correct. No precipitation is expected with dry
low levels.
Highs on Sunday should end up a few degrees colder than Sunday
in the middle to upper 30s for most locations. Any clouds
Sunday evening should clear out leading to a cold night with
lows in the upper teens and low 20s inland and middle and upper
20s elsewhere.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
The big picture shows a large longwave trough dominating most
of North America, a longwave ridge along the West coast, and a
cutoff low near the Southwest US coast. The trough should
prevent any energy from the Southwest closed low from impacting
the local weather. and also keep temps at least several degrees
below average through most of the period, with the possible
exception of Thu which may see temps closer to average.
A potent shortwave trough coming across the North Pole this
weekend should dive into the longwave trough this week and
become negatively tilted as it enters central Canada and the
upper Great Lakes region during mid week. An associated Alberta
Clipper sfc low moving across these same areas will drag an
associated frontal system across the local area, with chance of
snow showers Wed night and possibly lingering into Thu AM. Any
accumulations from this look to be mostly on the light side, but
may have to watch for some moderate accumulation potential
across ern Long Island and SE CT as a secondary low starts to
develop just E or SE of Long Island.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
VFR. An isolated sprinkle or flurry is possible especially for
KSWF this evening, with no impact to cigs/vsbys.
WSW winds 10-15kt with gusts 20-25kt. Gusts end later this
evening after 00Z with winds veering W-WNW.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Gusts may not last until 03Z becoming more occasional after
00Z.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday and Sunday: VFR. W winds gust around 20kt during both
afternoons.
Monday and Tuesday: VFR. NW winds G15-20kt both afternoons.
Wednesday: VFR during the day. Chance of sub-VFR and snow at
night.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA conditions will continue on the ocean through at least Saturday
night. Have extended the Advisory until early Sunday morning with
the potential it will need to be extended into Sunday in subsequent
forecasts. Marginal SCA gusts are likely this evening into tonight
with seas around 5 ft. Conditions may briefly drop off on Saturday
before returning to SCA levels late Saturday and Saturday night. The
near shore waters could see gusts just under 25 ft at times tonight
and then again Saturday night, but have held off on an Advisory at
this time.
Sub SCA cond expected on all waters from Mon into daytime Wed.
Increasing SW flow ahead of an approaching frontal sys could lead to
minimal SCA cond on the ocean waters, with gusts up to 25 kt and
seas up to 5 ft.
&&
.HYDROLOGY...
No hydrologic impacts are expected through next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST Sunday for ANZ350-353-355.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...DBR/DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...JC/DBR
MARINE...BG/DS
HYDROLOGY...BG/DS