textproduct: New York

SYNOPSIS

High pressure over the area moves off the New England coast through tonight. A frontal system moves across the region Sunday into Sunday night. High pressure briefly builds on Monday before quickly giving way to developing low pressure over the southern states.

NEAR TERM /THROUGH SUNDAY/

Tonight will be dry as high pressure centered over the region moves off the New England coast through tonight. Meanwhile, a low pressure system will be moving out of the central plains states and into the Great Lakes region, and is associated with northern stream energy and a longwave trough. Temperatures will drop off quickly early tonight as winds become light and variable with mostly clear conditions. However, by the overnight temperatures will likely hold nearly steady, or even rise a few degrees especially along the coast, as warm advection develops with a warm front approaching to the southwest, and clouds increase.

SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/

Warm air advection increases into Sunday morning as the warm front nears the southern portions of the region, and possibly moves into the coastal region Sunday afternoon. Meanwhile, the surface low will be moving into the eastern Great Lakes region and into southern Canada. The upper trough will be rather flat and progressive across the northeast. This will bring a cold front quickly across the region late day Sunday into Sunday evening. Precipitation develops by late Sunday morning, and will be mainly rain, with a brief start of snow and snow mixed with rain across far western portions of Orange County and Western Passaic County as the warm air will not be reaching into the interior as the low begins to occlude. Precipitation will be generally light, but there may be a brief period of moderate rainfall along the coast where the strongest lift will be located.

Near zonal flow will continue across the eastern half of the country Monday and will allow the next northern stream amplifying trough to move out of the Pacific northwest and into the central plains early Monday. Meanwhile, surface high builds into the region late Sunday night into Monday morning, and with the progressive flow, moves quickly offshore Monday night.

The deep upper trough will bring the surface low out of the southeastern states late Monday night with a chance of precipitation across the region toward Tuesday morning. Enough low level warm air will be across the coastal regions for the precipitation to the all rain, however in the overrunning precipitation shield a rain/snow mix band will be possible, with even some sleet at times, while the farther inland areas will likely begin as all snow.

LONG TERM /TUESDAY THROUGH SATURDAY/

Key Points:

* A coastal low will pass south and east of the area on Tuesday, likely bringing the first accumulating snowfall to the area. Confidence is higher across the interior Lower Hudson Valley where an Advisory level (3-5 inch) or higher snowfall is possible. Uncertainty in snowfall totals remains farther south, especially along the coast.

* About 10 degrees below normal for high temperatures through the entire long term period. At the start of the period, low pressure will be moving up the southeast coast as a shortwave approaches from the west. By Tuesday afternoon, secondary low pressure will be deepening along the Mid- Atlantic coast as it aims to pass south and east of the area. Decent model spread remains with the track of the low. Some notable trends: past several runs of the GFS and GEFS have very gradually trended southeastward (colder), the ECMWF remains the farthest southeast and coldest and the NAM and Canadian bring the low right over Long Island (warmest). Additionally, the NBM probability in snow amounts have been gradually increasing. Leaning away from the NAM and Canadian solutions, especially given the latest Canadian ensemble still has a cluster of members well offshore. Current ptype and snow accumulation forecast reflects this thinking.

As mentioned, confidence in snow highest across the interior of the Lower Hudson Valley. Although a quick hitting storm, latest deterministic guidance came in with higher QPF totals than the latest NBM. This yielded snow amounts in Orange County, Putnam and western Passaic at Advisory levels. For CT and the rest of NJ and the Lower Hudson Valley amounts look to be closer to an inch or two. This area is where the largest uncertainty is. Closer to the coast confidence is higher in mainly rain (especially eastern Long Island), while some periods of snow and even a few tenths can not be ruled out.

At this time, winds do not look to be a concern with this system. However, the NAM's trend will have to be watched as it currently has a very strong LLJ moving over the area (80kts at 925mb).

High pressure builds in behind the departing low on Wednesday and will remain in control through the rest of the week aside from a cold frontal passage on Thursday. This is expected to be a dry frontal passage.

Next weekend there is potential for another system to impact the area, but at this time there is too much uncertainty for specifics on rain/snow and stuck close to the NBM during that period.

OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY

Sunday Afternoon/Night: Rain with MVFR/IFR conditions in the afternoon/early evening. S winds G20-25kt, highest near the coast. Improving to VFR after 00Z. Winds becoming W G15-20kt.

Monday: VFR. NW G15-20kt, mainly in the morning.

Tuesday: MVFR expected in the morning, IFR possible in the afternoon/evening. Precip type mainly snow at KSWF. Rain and/or snow at the onset at the other terminals, changing to rain in the morning. Winds become N in the afternoon with G15-25kt, highest at the coastal terminals.

Wednesday: VFR. NW G15-20kt early.

Thursday: VFR. WSW G15-20kt.

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

MARINE

With high pressure over the waters, and moves off the New England coast tonight, winds and seas remain below advisory levels across the forecast waters into early Sunday morning. A increasing southerly flow ahead of the next rapidly approaching frontal system Sunday will increase winds with ocean seas building and SCA conditions will develop by late Sunday morning on the ocean, south shore bays, and the far eastern Long Island Sound. There is some uncertainty with the strength of the gusts on the ocean waters with warm air moving over the colder waters. A SCA will be in effect for the above mentioned waters late Sunday morning, running through 100 AM EST Monday for the Sound and southern bays, and at least through Sunday night on the ocean. Small craft conditions may continue into Monday morning before falling below by midday as high pressure builds back into the region. Winds and seas then remain below advisory levels through Monday night.

Winds and seas increase through the day on Tuesday with the passage of an offshore low pressure system. By the afternoon, SCA wind gusts are likely on the ocean waters by the afternoon, and by the evening for the non-ocean waters. There may also be a brief period Tuesday night with gusts reaching gale criteria. Additionally, current wind forecast has seas reaching 5 to 8 feet for the ocean waters. It is worth noting that there is some uncertainty given the nature of the system. A small change in forecast track of the offshore low could cause a larger change in forecast winds than usual.

The system pull away on Wednesday and winds and seas gradually lower, likely falling below SCA criteria by Wednesday afternoon. The next shot at SCA criteria will be with a cold frontal passage on Thursday and then again next weekend with another area of low pressure potentially impacting the area.

HYDROLOGY

No hydrologic concerns expected through next week.

OKX WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 10 AM Sunday to 1 AM EST Monday for ANZ332-345. Small Craft Advisory from 10 AM Sunday to 6 AM EST Monday for ANZ350-353-355.