Vineyard Sound Marine Forecast
|Overnight...S Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 5 Ft. A Chance Of Showers, Then Showers With Isolated Tstms. Some Tstms May Produce Heavy Rainfall.|
|Wed...W Winds 15 To 20 Kt With Gusts Up To 25 Kt, Becoming Nw 5 To 10 Kt In The Afternoon. Seas 3 To 5 Ft. A Chance Of Showers.|
|Wed Night...E Winds 5 To 10 Kt. Seas 2 To 4 Ft.|
|Thu...Se Winds 5 To 10 Kt. Seas Around 2 Ft.|
|Thu Night And Fri...S Winds Around 10 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. A Chance Of Showers.|
|Fri Night...W Winds 5 To 10 Kt, Becoming N After Midnight. Seas Around 3 Ft.|
|Sat Through Sun Night...Sw Winds 5 To 10 Kt. Seas 2 To 3 Ft. Winds And Seas Higher In And Near Tstms. 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.|
| Area Forecast Discussion|
National Weather Service Boston/Norton MA
1222am EDT Wednesday July 6 2022
Scattered showers and perhaps a few embedded thunderstorms are possible tonight with brief heavy rain. Pleasant weather follows Wednesday into Thursday, then increasing rain chances Thursday night into at least Fri morning, as low pressure moves over or just south of Southern New England. High pressure then delivers a period of beautiful summer weather this weekend into early next week, with mild to warm days and cool nights, along with comfortable humidity. A warming and more humid trend may develop by next Tuesday, along with the chance of showers.
Near Term - Until 6am This Morning
Forecast remains on track. KBOX radar displaying scattered showers across southern New England this evening. Some instability is beginning to nose into the region from the west, thus there may be an opportunity for one or two of these showers to produce a rumble of thunder. Haven't detected any lightning thus far, but there will remain an opportunity over the next couple of hours as these light to moderate showers continue eastward over the region. Timing still appears to be on track as well. Expect showers to come to an end for most of the area by sunrise. Showers may linger a bit longer over the eastern areas with some short-term model guidance revealing shower potential through about mid-morning.
Short Term - 6am This Morning Through 6pm Thursday
Highlights... * Becoming partly sunny & warm Wednesday with highs in the lower-middle 80s * Dry weather Wednesday night with cool low temps for early July standards
Details... Wednesday... Low pressure tracking across northern New England tonight will be lifting into Quebec early Wednesday morning; dragging a cold front across the region. A few left over showers possible early Wed, but mainly dry weather expected with northwest flow behind the cold front allowing skies to become partly sunny. High temps reach the lower to middle 80s in most locations with decreasing humidity from northwest to southeast. Gradient will weaken a bit during the afternoon allowing for a bit of a sea breeze to develop on the coast. This could result in a few spot showers developing in the afternoon near the southeast New England coast on this sea breeze front, but areal coverage of any activity should be rather limited.
Wednesday night... Canadian high pressure will build into New England Wednesday night resulting in mainly clear skies with light-calm winds. This coupled with dry airmass in place for a good night of radiational cooling. Low temps should bottom out in the middle 50s to the lower 60s.
Long Term - Thursday Night Through Tuesday
* Chance of showers Thu night into Fri (especially Fri morning), as low pressure passes south of Southern New England
* High pressure then prevails Fri night thru early next week. This will support a rather prolonged period of beautiful summer weather, featuring warm/mild days and cool nights, along with comfortable humidity
Thursday... Dry NW flow lingers into at least Thu morning with drier than normal PWATs (Precipitable Waters) over SNE per ensembles. Cool start to the day with lows at sunrise in the 50s in many locations. Then clouds likely increase during the afternoon, as strong closed digs into Quebec, advecting plume of moisture from the OH valley into SNE. Mild/warm with highs in the upper 70s to lower 80s. Humidity remains relatively comfortable with dew pts 55-60.
Thu night/Friday... Lots of uncertainty here, as a potent mid level closed low digs across Quebec. Models including ensembles differ on amplitude of system and how much mid level flow backs across SNE. Even large differences between GEFS and ECENS, thus forecast confidence is well below average for this time range. Part of the problem is upstream convection, models having problems properly simulating thunderstorms, thus impacting downstream solutions. Ensembles do have 850 mb flow backing to the SW from 00z Fri to 12z Fri, thus this would be the window of highest pops. Not expecting much thunder, as weak surface low would likely track south of New England, cutting off warm sector from advancing north into the region. Ensembles do indicate NW flow and lower PWATs (Precipitable Waters) advecting in from the NW. Therefore, Friday afternoon could feature a drying trend. Nonetheless, lots of uncertainty Fri. Highs in the upper 70s to lower 80s, pending how much afternoon clearing develops.
The Weekend... Behind departing Quebec mid level low, anomalous dry (PWATs (Precipitable Waters) below normal) and cool airmass (850 mb temps cooler than normal) overspreads SNE. This will set the stage for a beautiful summer weekend, featuring mild/warm days and cool nights, along with comfortable humidity. Strong July sunshine will be offset below normal 850 mb temps, and warm temps in the afternoon to near normal values, upper 70s and low 80s. Dew pts in the 50s will support very comfortable nights, with overnight lows in the 50s.
Early Next Week
Ensembles suggest dry, warm and comfortable weather likely lingers into Monday. Around Tuesday, next Canadian trough begins to dig south. Thus SW flow may advect into SNE by Tue, beginning a warming, more humid trend
Forecaster Confidence Levels:
Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.
Tonight...High Confidence. A modest south-southwest LLJ will result in SW wind gusts of 20 to 30 knots developing tonight...despite the inversion. Long fetch should build seas to between 3 and 6 feet across the open waters. Small Craft Headlines continue for all waters.
Wednesday...High Confidence. Winds shift to the NW Wednesday morning behind the cold front. However, wind gusts should generally not exceed 20 knots. That being said; lingering small craft seas will linger into the afternoon across the outer-waters requiring headlines to be continued in these locations.
Wednesday night...High Confidence. High pressure builds over the waters which will result in winds/seas below small craft advisory thresholds.
Outlook /Thursday Night through Sunday/... Thursday: Winds less than 25 kt.
Thursday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers.
Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers.
Friday Night through Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Sunday: Winds less than 25 kt.
NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.
Small Craft Advisory until 6am EDT early this morning for ANZ230-236. Small Craft Advisory until 11am EDT this morning for ANZ231>234-251. Small Craft Advisory until 2pm EDT this afternoon for ANZ235- 237-250. Small Craft Advisory until 6pm EDT this evening for ANZ254>256.