Marine Weather and Tide Forecast for Greenport West, NY

NEAR TERM /THROUGH TONIGHT/
Only some cosmetic adjustments with regard to temps, dew points, and winds with tightening Ambrose style jet into this afternoon as the forecast remains primarily on track.

SW-S winds into this afternoon with high pressure centered off the Mid- Atlantic coast. With mostly sunny conditions and mixing up to 900- 850mb for western portions of the forecast area unaffected by an onshore flow, went a few degrees above deterministic NBM, which has been consistently below its 25th percentile for the past several runs. Highs ranging from the low-mid 80s in the urban corridor of NE NJ to the upper 60s for the south-facing shores of LI and SE CT.

Given the deep mixing expected through the day for the warmest areas, dew points are expected to remain mostly 40-45 despite a persistent SW flow. This deeper mixing and warm temperatures will cause RH values to drop to 25-35% this afternoon. This dry air combined with wind gusts 25-30 mph may allow for the elevated risk of fire spread. As such, a collaborated SPS for Northeast NJ, the Lower Hudson Valley and CT is posted to address this potential this afternoon into early evening.

Weakening convection ahead of an approaching cold front brings chances (20-40%) of residual showers pushing into the forecast area tonight. A rumble of thunder still cannot be ruled out over the Lower Hudson Valley and vicinity during the earlier evening hours.
Any convection that survives will likely be below severe thresholds.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
The cold front is expected to be in the vicinity of eastern LI at sunrise Wednesday. Building surface high pressure follows through the day and remains in control through Thursday as ridging continues aloft. Dry weather through at least Thursday afternoon. For highs on Wednesday, went closer to the warmer 50th percentile NBM given the progged temps at the top of the mixed layer and a NW flow.
Deterministic NBM looked good for Thursday with an onshore flow and more clouds around vs Weds.

Surface low pressure shifts NE through the eastern Great Lakes Region during Thursday night. A leading warm front is progged to reach part of the forecast area by daybreak Friday. Increased moisture with 850mb theta-e advection and isentropic lift bring chances (40-50%) of light rain or showers mainly after midnight.
Can't rule out an isolated rumble of thunder with some elevated instability, but it appears that any rainfall will more likely be relatively on the lighter side as guidance has consistently shown modest qpf totals for several days now.

LONG TERM /FRIDAY THROUGH MONDAY/
Digging trough into the Great Lakes region with a couple embedded shortwaves sends a frontal system toward the region late this week.
Associated warm front lifts thru locally Friday morning, with scattered showers possible to start before drying for the bulk of the afternoon. Attendant cold front then approaches late in the day, instigating another round of showers and perhaps tstorms as well ahead of the boundary Friday evening and night. Guidance is also converging on a frontal wave of low pressure developing along the boundary as it moves east, producing additional wet weather Saturday. The probability for severe weather is low. QPF outside any convective maxima thru this time should largely remain under an inch, though the slower progression of the entire system could enhance totals just a bit further.

Considerable uncertainty in the forecast moving into early next week, hinging on whether the associated upper low is able to sufficiently pass east, or cut off from the flow and meander nearby for several days. EPS and GEPS lean toward a cutoff solution, leading to a much more dreary outlook. Meanwhile, the bulk of 00Z GEFS members keep the system moving east, with high pressure quickly building in behind it early next week. Associated Pac energy remains offshore, and better sampling should help resolve the solution over the next day or two as it moves into British Columbia.

The region lies in the warm sector of the system on Friday and sets up the mildest day of the period. Temperatures away from maritime influence, generally west of the Hudson River, likely climb into the upper 70s and lower 80s, with potential for mid 80s. Cooler along the immediate coast with onshore southerly flow, closer to 70. The region should fall back to more typical conditions behind the system early next week as high pressure attempts to return, though temperatures could be cooler should a meandering upper low remain nearby.

AVIATION /14Z TUESDAY THROUGH SATURDAY/
High pressure remains centered offshore today ahead of an approaching cold front. The front moves through early Wednesday.

VFR thru the day.

General S/SW flow today, speeds increase to start with gusts 20 to 25 kt developing by late morning, and a sea breeze likely contributing a few additional knots to coastal terminals into the afternoon. Gusts persist this evening and into tonight, and LLWS is possible for a period at KISP and KGON with winds at 2kft above 40 kt. An approaching cold front introduces the chance for a few rain showers, mainly north and west of NYC terminals after 3Z. Conditions dry behind the front, with flow veering NW into mid Wed AM.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Isolated gusts 30 to 35 kt possible late this afternoon into early evening.

Brief MVFR conds possible tonight with a slight chance of rain showers.

OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY

Late tonight: A chance of rain showers north and west of NYC terminals with brief MVFR possible. A slight chance of showers for other terminals. A slight chance of thunderstorms, mainly in the evening north and west of NYC terminals. SW wind gusts near 20 kt, becoming more westerly late. LLWS east of NYC terminals with SW winds at 2kft near 40-45 kt.

Wednesday: VFR. NW wind gusts 15-20 kt during the day.

Thursday: Mainly VFR. MVFR or lower possible at night with a chance of showers, slight chance of thunderstorms.

Friday: MVFR or lower possible. A chance of showers. A chance of thunderstorms during the day. A slight chance of thunderstorms at night. SW wind gusts 15-20 kt afternoon into evening.

Saturday: MVFR or lower possible. A chance of showers. A slight chance of thunderstorms. NW winds gusts 15-20 kt during the day.

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


OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY

Late tonight: A chance of rain showers north and west of NYC terminals with brief MVFR possible. A slight chance of showers for other terminals. A slight chance of thunderstorms, mainly in the evening north and west of NYC terminals. SW wind gusts near 20 kt, becoming more westerly late. LLWS east of NYC terminals with SW winds at 2kft near 45-50 kt.

Wednesday: VFR. NW wind gusts 15-20 kt during the day.

Thursday: Mainly VFR. MVFR or lower possible at night with a chance of showers, slight chance of thunderstorms.

Friday: MVFR or lower possible. A chance of showers. A chance of thunderstorms during the day. A slight chance of thunderstorms at night. SW wind gusts 15-20 kt afternoon into evening.

Saturday: MVFR or lower possible. A chance of showers. A slight chance of thunderstorms. NW winds gusts 15-20 kt during the day.

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

MARINE
South to SW winds increase into the afternoon with SCA conditions developing on all waters this afternoon. A cold front then passes through late tonight into Wednesday morning with gusts still above 25 kt and elevated seas on the ocean. SCA has been extended to parts of Wednesday on the ocean. Only other adjustment to the SCA was to extend it through the entire night for most of the non-ocean waters. A period of sub-advisory conditions then follows for all waters for much of Weds afternoon through Thursday night as a high pressure ridge shifts through the region.

Strengthening southerly flow associated with an approaching frontal system could introduce a period of SCA conditions on the ocean beginning Friday, with wind gusts up to 25 kt and seas 5 to 6 ft.
Winds lighten Friday night, but elevated seas may linger into the weekend.

FIRE WEATHER
Dry conditions with the combination of low relative humidity values between mostly 25 and 35 percent and frequent wind gusts of 25 to 30 mph will create an elevated risk for fire spread this afternoon into early evening. Special Weather Statements are in effect for most of the area (excludes NYC and LI).

HYDROLOGY
There are no hydrologic concerns through the forecast period.

TIDES/COASTAL FLOODING
Astronomically high tides will couple with a modest S/SW flow to allow water levels to approach or a low probability of just touching minor flood thresholds in the most vulnerable locales of coastal Nassau, Queens, and Fairfield during this evening's high tide cycle. No headlines have been issued at the present time.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ331-332- 340-345.
Small Craft Advisory until 2 AM EDT Wednesday for ANZ335-338.
Small Craft Advisory until 2 PM EDT Wednesday for ANZ350-353.
Small Craft Advisory until 11 AM EDT Wednesday for ANZ355.