textproduct: New York

SYNOPSIS

High pressure moves well out into the Atlantic into this evening. A weak wave of low pressure moves northward within the Western Atlantic late tonight into early Wednesday. A stronger wave of low pressure approaches from the west Wednesday afternoon into Wednesday evening with a corresponding strong cold front moving across late Wednesday night. High pressure builds in from the south and west Thursday into Friday. A weak upper level disturbance will move across Friday night into Saturday morning. An Arctic cold front will approach Saturday night, then move through on Sunday as offshore low pressure forms along the front. Strong high pressure will then build in Monday as the low intensifies near Atlantic Canada.

NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/

Key Points:

* Dry tonight but relatively warmer low temperatures compared to previous night.

Going into tonight, low level winds shift more to southwesterly. This sets up warm air advection. Clouds increase in coverage and SW winds at the surface remain steady.

Radiational cooling will be mitigated as a result. NBM temperatures were used for lows, ranging from near 20 to near 30. These lows will actually likely be set during this evening with temperatures upward late tonight into early Wednesday as clouds lower and thicken. Going into Wednesday morning temperatures of low to upper 20s are expected across much of the interior while closer to the coast, temperatures are mostly in the low to mid 30s.

SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/

Key Points:

* Minor snow event forecast for Western Passaic NJ, Orange County NY, Putnam County NY and northern tip of Fairfield County CT Wednesday. Snow mixing with rain much of the event will limit accumulations of snow. Total snow accumulations forecast of near 1 inch or less.

* For interior areas mentioned in 1st point, a brief period of freezing rain is possible at the onset early Wednesday but probability for this is low.

* Rain expected for the rest of the forecast region not mentioned in the 1st point for Wednesday into Wednesday evening. * Gusty winds forecast Wednesday and Thursday. Max gusts forecast mainly near 35 to 40 mph but some peak gusts to near 45 to 50 mph are possible, especially Thursday.

Upper level jet has been situated south of the region. One particular streak is shown in the numerical weather prediction models to pass south of the region Wednesday into Wednesday evening. The local area is near the left front quad of that jet streak. Then, the models show this jet streak to move southeast away from the region Wednesday night into Thursday. Jet remains situated south of the region Thursday into Thursday night.

At the surface, a strong wave of low pressure, down to near 987 mb according to forecast models, moves from the Great Lakes into interior parts of the Northeast Wednesday. This will have an associated strong cold front approaching the region.

Forcing for lift increases with associated omega increase from late morning through the afternoon. This is when precipitation will develop and move east within the region with highest POPs. Ambient temperature will be key and timing differences with onset of precipitation will be quite important as well.

Locations north and west of NYC have a wintry mix and with dynamic cooling expected, will likely keep that wintry mix as wet bulb cooling cools the lower levels of the atmosphere. The wintry mix will be mainly rain and snow. Still have these locations with rising temperatures to the low to mid 30s so any snow accumulations are forecast to be limited to near 1 inch or less. The timing of this event will really limit the snowfall accumulation in this case.

For other locations within the forecast region, a rain event is expected. Steady light to occasionally moderate rain is expected, mainly from late morning through the afternoon. This rain will linger into the evening especially across eastern parts of Long Island and Southern CT. Brief heavy rain will be possible with that omega increase.

Max temperatures forecast for Wednesday range from the mid 30s for Orange County NY to lower 50s across Eastern Long Island. For Wednesday night, the strong cold frontal passage late will be ushering in a much colder airmass, with lows ranging from lower 20s to lower 30s and with increasing winds, wind chills by early Thursday morning are mainly near the 10 to 20 degrees range.

A much colder day is expected Thursday compared to the previous day. This continental polar airmass will be moving in and with 850mb temperatures near -15 degrees C. Temperatures only expected to rise into the 30s for high temperatures Thursday for most locations, well below normal for this time of year. Another day of gusty winds expected as well. Max gusts look to stay near 35 to 40 mph but an occasional peak gust to near 45 to 50 mph is possible.

LONG TERM /FRIDAY THROUGH TUESDAY/

Key Points:

* Temperatures will be at least several degrees below normal Friday and Saturday.

* A clipper low may bring light snow or flurries Friday night into Saturday morning.

* An Arctic cold front and associated upper level disturbance will bring a better chance for light snow Saturday night into Sunday morning.

* A shot of Arctic air will follow for later Sunday into Tuesday, with temps up to 10 degrees below normal.

Models continue to trend weaker with the approaching upper level sys Fri night, at least at the surface. With the associated mid level level vort max aimed at the CWA, kept a mention for some light snow, with little/no accumulation expected.

A potent closed low diving SE out of central Canada Sat night and passing N on Sunday will drive an Arctic cold front through on Sunday, which will be capable of producing some accumulating light snow. Miller B type cyclogenesis is also likely along the front on Sunday SE of New England after it passes through, likely too late to have impact on local snowfall totals. This combo will bring colder conditions for later Sunday through Tue, and it could also become blustery Sunday night into Mon due to the tight pressure gradient between the intensifying low as it heads toward Atlantic Canada and high pressure building to the west. The high should build over the area on Tue.

Temps will run about 10 degrees below normal on Mon, with lows in the teens and lower 20s, and highs from the mid 20s to lower 30s. Wind chills early Mon morning could drop to the single digits throughout. Only slight moderation in high temps (30-35) expected for Tue, with less wind chill impact as winds lighten.

OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY

Wednesday: MVFR or lower with a chance of rain/snow across interior Lower Hudson Valley, rain elsewhere. S-SW 10-15 G25-30 KT possible.

Thursday: VFR. W gusts 25- to around 30 kt.

Friday: Mainly VFR. MVFR possible in any rain or snow showers late at night. W gusts around 20 kt.

Saturday: Brief MVFR possible east early, otherwise VFR. W gusts 15-20 kt.

Sunday: MVFR or lower in snow. NW flow with guts to around 20 kt.

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

MARINE

Forecast waters are initially below SCA thresholds heading into this evening. Then winds are expected to increase tonight with all waters expected to reach SCA levels for wind gusts and ocean for both winds and gusts. The winds further increase Wednesday with gales expected on most waters. SCA remains for NY Harbor. Ocean seas Wednesday forecast to build to near 7 to 11 feet with 3 to 5 feet for the Eastern Long Island Sound seas.

After a brief decrease in synoptic pressure gradient Wednesday evening, the pressure gradient increases again late Wednesday night into Thursday. For Wednesday night, winds eventually lower to SCA levels for most waters except for ocean which will take longer for gales to subside. NY Harbor probably remains at SCA levels. Another round of gales possible for Thursday into Thursday night. Ocean seas remain near 7 to 11 ft Wednesday night through Thursday night. A greater part of Long Island is forecast to have seas of 3 to 5 feet Thursday into Thursday night.

SCA cond on all waters Fri morning (W winds gusting to 25-30 kt, with seas 5-10 ft on the ocean and 4-5 ft on the central/ern Sound) should slowly wind down Fri afternoon, lingering on the ocean waters (gusts up to 25 kt and seas 4-6 ft) into Fri evening. After an upper level disturbance passes by, SCA cond should return to the ocean waters Sat morning and the non ocean waters Sat afternoon, with gusts 25-30 kt and ocean seas 3-5 ft, and continue into Sat night.

After an Arctic cold frontal passage on Sunday, then as low pressure develops/intensifies along the front SE of New England, winds should veer NW, and gale force wind gusts will be possible. Seas should build to 5-8 ft on the ocean, and up to 5 ft on the central/ern Sound.

HYDROLOGY

Less than a quarter of an inch of rain forecast Wednesday into Wednesday night. Some locally higher amounts possible. No hydrologic impacts are expected through the week.

OKX WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EST Wednesday for ANZ331-332- 335-340-345-350-353-355. Gale Warning from 6 AM to 6 PM EST Wednesday for ANZ331-332- 335-340-345. Small Craft Advisory until 6 PM EST Wednesday for ANZ338. Gale Warning from 6 AM Wednesday to 6 AM EST Thursday for ANZ350-353. Gale Warning from 6 AM Wednesday to 1 AM EST Thursday for ANZ355.