Marine Weather Net

Vineyard Sound Marine Forecast


TONIGHT

W
WINDS
20 - 25
KNOTS

FRI

W
WINDS
20 - 25
KNOTS

FRI NIGHT

W
WINDS
15 - 20
KNOTS

SAT

W
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
ANZ233 Forecast Issued: 716 PM EDT Thu Apr 09 2020

GALE WARNING IN EFFECT THROUGH LATE FRIDAY NIGHT
Tonight...W Winds 20 To 25 Kt With Gusts Up To 40 Kt. Seas 4 To 7 Ft. A Chance Of Showers This Evening.
Fri...W Winds 20 To 25 Kt, Increasing To 25 To 30 Kt In The Afternoon. Seas 4 To 7 Ft.
Fri Night...W Winds 15 To 20 Kt, Diminishing To 10 To 15 Kt After Midnight. Gusts Up To 30 Kt. Seas 3 To 5 Ft.
Sat...W Winds 10 To 15 Kt With Gusts Up To 30 Kt. Seas 2 To 4 Ft.
Sat Night...W Winds 10 To 15 Kt, Diminishing To 5 To 10 Kt After Midnight. Gusts Up To 25 Kt. Seas 2 To 3 Ft.
Sun...Sw Winds 5 To 10 Kt, Becoming S 10 To 15 Kt With Gusts Up To 25 Kt In The Afternoon. Seas 2 To 4 Ft.
Sun Night...S Winds 10 To 15 Kt, Increasing To 15 To 20 Kt After Midnight. Gusts Up To 30 Kt. Seas 3 To 5 Ft. A Chance Of Showers.
Mon...S Winds 25 To 30 Kt With Gusts Up To 35 Kt. Seas 5 To 8 Ft. Showers Likely.
Mon Night...Sw Winds 20 To 25 Kt With Gusts Up To 35 Kt. Seas 5 To 8 Ft. A Chance Of Showers.
Tue And Tue Night...W Winds 10 To 15 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Seas Are Reported As Significant Wave Height, Which Is The Average Of The Highest Third Of The Waves. Individual Wave Heights May Be More Than Twice The Significant Wave Height.
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Area Forecast Discussion
National Weather Service Boston/Norton MA
756pm EDT Thu April 9 2020

Synopsis
Low pressure east of Massachusetts will move through the Gulf of Maine tonight. Strong gusty west winds will bring in cooler and drier air tonight. Friday will be cooler along with a few light showers as the strong low pressure exits Maine into the Maritimes. High pressure brings drier weather for the weekend. The next weather system brings wind and rain Sunday night and Monday. The weather then dries out again for much of next midweek.

Near Term - Until 6am Friday Morning
745 pm

Low pressure was located east of the Merrimack River at 7 PM with strongest pressure falls over the Gulf of Maine. Expect the low to move northeast across the gulf, eventually reaching the Maritimes. Strong pressure gradient moving into Western MA/CT will provide for strong west winds. BOX VAD Wind Profile shows 35 kt winds at 2000 feet AGL and Albany VAD Wind Profile shows 40 kt winds at 3000-4000 feet. Expect gusts in this range for at least the first part of the night, diminishing a little overnight as the pressure gradient weakens.

Satellite images show clearing skies over CT/RI and Western MA. This clearing is trending northeast and will sweep out of Central and Eastern MA early tonight.

No significant changes to the forecast planned. A Wind Advisory continues due to the observed gusts at 7pm and observed low- level winds aloft from the regional radars.

Previous discussion... Triple point low developed over our area this afternoon, and based on 4 pm obs was passing over eastern MA. In the vicinity of this low there is a bit of a lull in the winds, around 10-15 mph with some gusts to 30 mph. Otherwise, winds are ramping up, with W/NW winds gusting to 35-45 mph west of the low/cold front (western MA into north central CT), and SSE gusts 30-50 mph near the Cape/Islands in the warm sector. There were still some lightning pulses near/south of south east MA, where MUCape managed to climb to 500-1000 J/kg!

The low and cold front track eastward over the next 2 hours, moving offshore 22-23Z timeframe, taking the showers with it. By 00Z there is still a slight chance of showers in northeast MA and into the Cape, then dry conditions thereafter. Winds will become more uniform W/NW 15-25 mph with gusts 35-50 mph. Wind Advisory continues until 9 pm this evening. After 9 pm winds diminish but gusts of 25 to 30 mph linger into the overnight, with some higher gusts 30 to 40 mph for the overnight along the immediate east coastal MA shoreline, the Cape and Islands, and Block Island.

Decreasing clouds behind the front/low this evening, with skies becoming mostly clear. However later tonight an increase in clouds with chance of showers on Martha's Vineyard/Nantucket with short wave passing through with enough lingering moisture to support low chance/slight chance pops. Also, wrap around moisture behind the low and the approach of a mid level trough axis could result in some snow showers over the interior high terrain of NW MA.

Short Term - 6am Friday Morning Through 6pm Friday
Friday ... Some locales will have sunshine to start the day, but increasing clouds is expected during the morning as wrap around moisture behind the surface low moves into our area, and mid level trough axis sweeps through southern New England as well. The cyclonic flow aloft and very cold temps aloft will yield lots of diurnal clouds and a few scattered showers (snow showers high terrain possible) as well. Not a wash out but will have to dodge a few showers especially across northern MA. Otherwise mainly dry and cool with highs 45-50 but it will feel cooler given a gusty west wind up to 30-40 mph. There is a chance that we could have higher gusts, but not enough confidence at this time for Wind Advisory headlines.

Long Term - Friday Night Through Thursday
Big Picture... Closed low moves off through the Maritimes Friday night and Saturday. West Atlantic ridge builds over the Eastern Seaboard this weekend, then moves out to sea Sunday night. Southern stream jet then takes over and pulls a closed low from the Desert Southwest. this energy from this low generates a surface low over the Southern High Plains and pushes it northeast up the Ohio Valley and through the Great Lakes Monday. Broad upper trough remains over the USA through much of next week.

Mass fields are similar through Monday. The broad pattern remains similar through the week while the general details diverge. Moderate to high confidence in the forecast, with highest confidence over the weekend.

Daily Concerns... Friday night... West-northwest low level winds begin to diminish, but with 30 to 35 kt wind speeds at 925 mb which might still gust to the surface early in the night. Expect further diminishing during the night.

Upper trough lifts through the Maritimes. A shortwave moves through the trailing side of the trough and crosses Srn New England Friday night. The cold pool(a region of relatively cold air) associated with the shortwave reaches -34C. Cross sections show lingering moisture between 800 and 900 mb, but with dry air underneath. This suggests lingering clouds over northern MA and the Berkshire East Slopes, diminishing during the day Saturday.

Saturday and Sunday... High pressure builds overhead Saturday and moves off to the east Sunday. Increasing moisture above 850 mb Sunday suggests increasing sky cover through the day but no precip. West-northwest winds in the mixed layer Saturday reach 25-30 kt. Mixing reaches to at least 850 mb, possibly close to 800 mb thanks to the cold air aloft. Temperatures -4C to -6C support max surface temps upper 40s to low 50s.

Ridge moves east by Sunday, with surface winds picking up from the south. Expect increasing moisture aloft, bringing increasing clouds and limiting mixing depth. Forecast temps of 8-10C at 925 mb suggest max temps near 60.

Sunday night and Monday... Upper high to our east brings a southwest flow aloft over the USA East Coast. This draws surface low pressure up the Ohio Valley and over the Great Lakes. Upper jet pattern over New England is mediocre for generating lift, but the low level flow shows a 70 to 85 kt low level south jet. This should be enough to generate lift during the late night and on Monday. PW values (Precipitable Water values) rise quickly to 1.3 inches, which by climatology is high-end for the date. Expect strong south winds and showers with local downpours. Low pressure swings a cold front through Southern New England Monday night, with winds shifting out of the west and diminishing overnight.

Tuesday through Thursday... Low pressure exits through northern Quebec Tuesday morning. West winds and drier air then take over. There are signs of an offshore low passing south of New England Wednesday. Given the position of the upper jet at that time, expect the low to remain too far offshore to bring precipitation to the region. The forecast is for dry weather much of next midweek.

Marine
Tonight... West winds and gusts to 40 to 45 kt as low pressure moves off toward the Maritimes. Winds may diminish a little overnight. Drier air will bring clearing skies. Seas linger at 5 to 10 feet.

Friday ... Low pressure over the Maritimes will bring west gales over the waters. Seas build to 5 to 12 feet. Winds will diminish toward evening.

Outlook /Friday Night through Tuesday/... Friday Night: Low risk for gale force winds with gusts up to 35 kt. Seas 5 to 10 feet, subsiding overnight.

Saturday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas.

Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft.
Sunday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas locally approaching 5 ft.

Sunday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. Chance of rain showers, mainly after midnight.

Monday: Moderate risk for gale force winds with gusts up to 40 kt. Rough seas up to 18 ft. Rain showers likely.

Monday Night: Low risk for gale force winds with gusts up to 40 kt. Rough seas up to 18 ft. Chance of rain showers.
Tuesday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 12 ft.

Tides / Coastal Flooding
430pm Update:

Another round of minor coastal flooding this evening/overnight high tide, given continued high astronomical tides. Coastal Flood Advisories remain in effect for the southern and eastern coasts into Friday morning.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...Wind Advisory until 10pm EDT this evening for CTZ002>004. MA...Wind Advisory until 10pm EDT this evening for MAZ002>024-026. Coastal Flood Advisory until 8am EDT Friday for MAZ007-015- 016-019-022. RI...Wind Advisory until 10pm EDT this evening for RIZ001>004- 006>008. Coastal Flood Advisory until 8am EDT Friday for RIZ002- 004>007.
MARINE...
Gale Warning until 8pm EDT Friday for ANZ231-232-251. Gale Warning until 3am EDT Saturday for ANZ233>235-237-250- 254>256. Gale Warning until 2pm EDT Friday for ANZ230. Gale Warning until 1am EDT Friday for ANZ236.