Marine Weather Net

Montauk NY to Marthas Vineyard out 20 NM South of Block Island Marine Forecast


TONIGHT

NW
WINDS
20 - 25
KNOTS

SUN

NW
WINDS
15 - 20
KNOTS

SUN NIGHT

NW
WINDS
5 - 10
KNOTS

MON

S
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
ANZ256 Forecast Issued: 701 PM EST Sat Dec 03 2022

GALE WARNING IN EFFECT UNTIL 1 AM EST SUNDAY
Tonight...W Winds 25 To 30 Kt With Gusts Up To 40 Kt, Becoming Nw 20 To 25 Kt With Gusts Up To 30 Kt After Midnight. Seas 7 To 10 Ft. A Chance Of Showers This Evening.
Sun...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt, Diminishing To 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 4 To 7 Ft.
Sun Night...Nw Winds 5 To 10 Kt, Becoming W After Midnight. Seas 2 To 3 Ft.
Mon...S Winds 5 To 10 Kt. Seas Around 2 Ft.
Mon Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft.
Tue And Tue Night...Se Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 5 Ft. Rain.
Wed And Wed Night...S Winds 15 To 20 Kt, Becoming W 10 To 15 Kt. Gusts Up To 25 Kt. Seas 5 To 6 Ft. Rain.
Thu...Nw Winds 10 To 15 Kt. Seas 4 To 5 Ft. A Chance Of Rain.
Thu Night...N Winds 15 To 20 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.
SHARE THIS PAGE:           
Area Forecast Discussion
National Weather Service Boston/Norton MA
705pm EST Sat Dec 3 2022

Synopsis
Dry and chilly weather returns tonight into Sunday, with a warming trend through mid week, but will be accompanied by rain and gusty winds. Trending drier and colder late next week.

Near Term - Until 6am Sunday Morning
7 PM

Have made some adjustments to PoPs, wind speed/gusts in the latest update. Have increased and tried to time down the shower activity and wind gusts immediately behind the line as it is associated with the cold front swinging through. Mostly blended toward the latest HRRRE guidance as it appears to be doing well based on current observations. Think that given the colder WNW/NW flow in wake of the front and 30-40 kts of wind aloft, could see these gusts for most of the evening. This is also associated with a 3-5 hPa pressure rise/fall couplet. Should see the winds/gusts come down by the early Sunday morning hours.

Previous discussion... Precipitation still in place across most of southern New England this afternoon. Timing-wise, the initial back edge should reach central MA and eastern CT about 3 PM, then reach the east coast and Cape Cod Canal about 5 PM. This area should be well offshore by 7 PM.

The latest high resolution guidance continued to advertise the idea of a second band of rainfall, this time with the actual cold front. This area should arrive into western MA sometime between 5-6 PM, then move off the coast between 9-11 PM. This will be well after sunset, so expecting less instability to be in place, leading to more scattered precipitation. Not thinking it will be cold enough to get anything other than rainfall. But will need to monitor the progress of the low level cold air closely.

Winds will remain gusty this evening, and diminish after midnight with the arrival of the drier air. Still do not think Wind Advisory levels will be widespread enough to warrant issuing one now. Turning colder tonight as well, but near normal for early December.

Short Term - 6am Sunday Morning Through Sunday Night

High pressure builds into the central Appalachians Sunday into Sunday night, but will nose its way into southern New England during this time. Dry weather will prevail, with below normal temperatures. While still gusty Sunday morning, not expecting speeds to be that unusual for this time of year.

Long Term - Monday Through Saturday
Highlights

* Dry to start the week off with near seasonable temperatures.

* Unsettled Tuesday through Wednesday and perhaps into Thu. May be breezy at times with above normal temperatures.

* Confidence lowers late in the week and through the weekend, but temperatures appear to be trending cooler than normal.

Monday... Stuck under cyclonic flow through the period with a shortwave ridge sliding through southern New England. May have a subtle shortwave slide into the region late in the day. At the surface high pressure builds offshore and moves toward Nova Scotia as the day progresses.

Will have dry and quiet weather through this period with high pressure under control. Temps aloft will be increasing under SSW/S flow at 925 hPa. Anticipate temps to increase to roughly 0-3 degrees Celsius at 925 hPa. The result will be temps in the 40s across the interior and the upper 40s to low 50s along the south coast. Mid to high clouds push in late. Not out of the question we could get a bit warmer if clouds take a bit longer to get in, but is something we can dive deeper into in future updates.

Midweek... Still stuck under cyclonic flow through the vast majority of this period. Will have a few shortwaves embedded within the flow swinging through the region. The first slides from the Upper Mississippi River Valley late on Monday into the eastern Great Lakes by Tuesday afternoon. The next wave lifts in from the High Plains/Mid Mississippi River Valley late on Tuesday into the eastern Great Lakes/northern New England by late Wednesday. May have a bit of a pattern change starting up Thursday as a wave ejects from the Southwest US into the Central US. At the surface will have a slow moving cold front begin to slide in on Tuesday. The front stalls out nearby/over our region heading into Wednesday. Should see another low develop along the front on Wednesday, which should help finally kick it offshore heading into Thursday. High pressure nudges into from Ontario/Quebec on Thursday.

Main concern during this period is the potential for strong wind gusts Tuesday and Wednesday. Ahead of the cold front will see S to SSW flow at 850 hPa with a 30-50 kt low level jet in place both days, but flow becomes more SW/WSW later on Wednesday once the front passes through. Through this period does appear we've got roughly 1- 2 STD above climatology for wind speed in the Tue-Wednesday period with the NAEFS. Have roughly 2-2.5 STD above climatology for the U and V components on these days as well. At this point main source for uncertainty is that there may be a bit of an inversion to overcome on both days per GFS (Global Forecast System) Bufkit soundings. However, if there is a risk of tapping into the higher gusts it appears to be Wednesday at this point with 30-45 kt winds in the 1-3 kft level. Did bump up wind speeds/gusts a bit in the latest update through this period, but may need to increased further especially if we can mix a bit higher.

Think that in the Tue-Wednesday period is the best shot for up to an inch of rainfall. Anticipate that the heaviest rains will fall late on Tuesday into early Wednesday, which coincides with roughly when we see the strongest S/SSW low level jet lifting through. Will also see temperatures trending above normal as 925 hPa temps get to roughly 4- 9 degrees Celsius on Tuesday and 8-11 degrees Celsius on Wed. The result are highs generally in the 50s on both days with Wednesday being the warmer of the two days.

May be a bit drier on Thursday, but there is some uncertainty as another shortwave lifts in along the ridge axis. Given the forcing did stick with the NBM slight chances of precip, but this could very well be overkill especially with drier N/NW air advecting in.

Friday through the Weekend... Considerable uncertainty during this timeframe. Most of it having to do with how models handle a trough lifting in from the Central US late on Friday into Saturday. Questions at this point are the amplitude and timing of the trough pushing through. Due to this have just stuck with the NBM at this point, which keeps slight chances to chances of precipitation.

Confidence a bit higher in temperatures trending cooler with NE to NNE flow aloft. Should see readings in the 40s.

Marine
Forecaster Confidence Levels:

Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.

7 PM

Extended Gale Warnings across interior waters until 06Z. Still appears we have roughly 35-40 kts of wind in wake of the cold front. Given the colder air advection and warm waters it will not be difficult to mix these winds down. Should see the gusts diminishing gradually late tonight into early Sunday AM.

Previous discussion... Extended Gale Warnings for time this evening, mainly by 2-3 hours. A cold front will cross the waters this evening. Small Craft Advisories will be needed into Sunday morning for most waters, and could linger into Sunday afternoon for the eastern waters. High pressure builds over the waters Sunday into Sunday night.

Outlook /Monday through Thursday/... Monday: Winds less than 25 kt.

Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft.
Tuesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of rain.

Tuesday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Rain.

Wednesday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Rain.

Wednesday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of rain.

Thursday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.

Marine
Gale Warning until 1am EST Sunday for ANZ230>237-250-251- 254>256.