textproduct: New York

SYNOPSIS

Weak high pressure settles nearby and just south of the area today before moving offshore tonight. A strong cold front then approaches later Saturday into Saturday evening. Low pressure will from along the front and move by to the south, then east of the area on Sunday. High pressure will then build into the region Sunday night into Monday, and last into the middle of next week.

NEAR TERM /THROUGH TONIGHT/

Key Points:

* Dry and cold.

After an unseasonably cold start to the day, temperatures moderate a little, but temperatures remain well below normal through the day despite sunshine. The pressure gradient will gradually decrease through the afternoon, especially for the late afternoon and early evening. Another unseasonably cold and brisk day is on tap with dry air in place as high pressure builds across to the immediate south. Dewpoints remain near 10 to the teens all day and with a west wind gusting mainly at 20 to 25 mph it will feel like it is in the 20s this afternoon. For tonight lighter winds set up with mainly clear skies for the first half of the night. Temperatures will settle into the lower 20s in most spots, with a few upper teens to the NW, and upper 20s in the NYC metro. Some high clouds work in late at night and closer to daybreak.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Key Points:

* The first accumulating snow of the season is possible Saturday night into Sunday morning, with the highest chance of snow accumulation further south and east across the region.

During Saturday the winds become more WSW which helps temperatures approach 40 in the afternoon closer to the coast, with mainly upper 30s elsewhere. Clouds will work in with shearing out upper level energy, with mainly mostly cloudy skies expected. A potent shortwave rounding the base of the eastern trough approaches Saturday night. Skies will be cloudy with the chance of snow increasing later in the evening, and especially after midnight and into early Sunday morning. Profiles appear mainly cold enough for primarily all snow region wide, with perhaps a brief wintry mix at onset across the southern and eastern coastal sections of Long Island. Latest BUFKIT forecast soundings do show a cold profile overall, and with high RH with omega in the snow growth region. While QPF with this system appears modest at best due to the progressive nature of the pattern, the main question pertains to snow ratios. With soundings showing dendritic snow potential snow ratios could be higher than usual. Didn't go with the highest snow ratios of the NBM, but tempered them slightly down closer to 13:1 or so initially, and then closer to 15:1 at the end of the event, but overall should do better than the more typically 10:1 ratio for our region. The steadiest snow looks to take place towards or just before sunrise early Sunday morning, mainly from 06z to 12z, and more like 08z to 15z further south east.

The PVA should should shut off just after 12z further west, and just after 15z-17z further east. This will end the snowfall as the front works through and cold advection begins to max out and dry out the column for towards mid day and the afternoon. Overall preliminary indications are for 2 to 4 inches of snow across Long Island, closer to 2 to 3 inch amounts into coastal CT most of metro NE NJ, and NYC, with lesser amounts of 1 to 2 inches further NW. If the system slows down or speeds up these amounts could change. After collaboration have held off on issuance of winter weather advisories for the time being, and waiting for confidence to increase a bit more before issuing. The overall progressive nature of the synoptic pattern should preclude a more significant snowfall.

Dry and much colder air comes in Sunday afternoon into Sunday night. This air mass should edge out previous cold air masses so far this season with the coldest air of the season likely taking place for Sunday night into Monday morning with 850 mb temperatures likely getting as cold as -14 to -16 C. This should translate to low temperatures getting solidly into the teens across the majority of the region, and close to 10 above across far northern sections early Monday morning. Wind chills towards early Monday morning will get primarily into the single digits, to around 0 across northern most sections on a gusty NW wind.

LONG TERM /MONDAY THROUGH THURSDAY/

NBM was followed with only some downward adjustments to winds on Monday.

Key Points:

* Warming, but still below normal temperatures through Wednesday before getting above normal on Thursday. No Cold Weather Advisories expected.

* Rain possible on Thursday with no hydrologic impacts anticipated.

Global models and ensembles are in good agreement with mainly dry conditions for Monday through Wednesday night with high pressure in control. A cold front approaches on Thursday with a chance of rain. So far it appears that chances begin in the afternoon with a better chance at night.

OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY

Saturday: VFR. Occasional gusts 16-19kt from the WSW possible.

Saturday night: Snow moving in during the late evening and overnight with MVFR to IFR, possibly LIFR late at night.

Sunday: MVFR to IFR, possibly LIFR at times, in snow, mainly in the morning. Snow tapers off from west to east afternoon into early evening. Improving conditions afternoon into evening with VFR returning. NW winds gust around 25kt in the afternoon and night with peak gusts around 30kt.

Monday: Mainly VFR. NW winds G20-25kt. Gusts lower at night with some gusts to 20kt.

Tuesday: VFR.

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

MARINE

Small craft conditions continue on most of the waters today, with sub advisory conditions gradually working into the western non-ocean waters this afternoon. Lighter winds prevail tonight with a weakening pressure gradient. Sub advisory conditions should prevail on the ocean on Saturday despite an increasing WSW flow regime with ocean seas at mainly 3 to 4 ft. The winds switch to the NW with a cold frontal passage into Sunday morning with small craft conditions returning to all waters by the late afternoon and evening. A period of gales on the ocean may follow during Sunday night. Still some gales possible on the ocean Monday morning, otherwise, winds diminish, but remain at advisory levels through the day. Sub- advisory conditions for the non-ocean waters Monday night, but still a threat of 25kt winds and/or elevated seas on the ocean through Tuesday afternoon before all waters are finally below advisory levels Tuesday night.

HYDROLOGY

There are no hydrologic impacts expected through the entire forecast period.

OKX WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ331- 332-340-345-350-353. Small Craft Advisory until 1 PM EST this afternoon for ANZ335- 338-355.