Marine Weather Net

Provincetown MA to Chatham MA to Nantucket MA out 20 NM Marine Forecast




10 - 15


5 - 10


10 - 15

The Marine Weather Forecast In Detail:
ANZ254 Forecast Issued: 108 AM EDT Wed May 18 2022

Rest Of Tonight...W Winds Around 15 Kt With Gusts Up To 25 Kt. Seas 3 To 4 Ft.
Wed...W Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 3 To 5 Ft.
Wed Night...Sw Winds 5 To 10 Kt. Seas 2 To 4 Ft.
Thu...S Winds 10 To 15 Kt. Gusts Up To 20 Kt In The Afternoon. Seas 2 To 4 Ft. Patchy Fog. Showers Likely. Vsby 1 To 3 Nm.
Thu Night...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt, Becoming Nw After Midnight. Seas 3 To 5 Ft. Patchy Fog. Vsby 1 To 3 Nm.
Fri And Fri Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 5 Ft.
Sat And Sat Night...Sw Winds Around 15 Kt With Gusts Up To 20 Kt. Seas 4 To 5 Ft.
Sun And Sun Night...Sw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 6 Ft. A Chance Of Showers. 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
151am EDT Wednesday May 18 2022

Dry weather, low humidity and seasonably mild conditions persist across southern New England Wednesday. Thursday will feature cool and cloudy conditions with rain in the morning, then tapering off in the afternoon from west to east. A significant warmup then begins Friday, peaking Saturday with the season's first 90 degree highs looking likely. A cold front arrives on Sunday with cooler temperatures and the chance for showers and thunderstorms.


No change from previous forecast, seasonably cool overnight, with lows in the 40s for most locations. Previous discussion below.


Very dry airmass in place across the region, with dew pts in the 30s. Although, modest cold air advection (down to +2C to +3C at 850 mb by 12z) will preclude winds from decoupling and temps bottoming out. However, winds will become light overnight, already less than 10 kt at MVY, FMH and HYA. Therefore, incorporated some of the cooler MOS guidance to adjust overnight mins downward a bit. Nonetheless, seasonably cool tonight with most locations in the 40s, around 50 in Boston, Providence and Hartford, but some upper 30s possible in northwest MA.

.SHORT TERM /5am THIS MORNING THROUGH 6pm THURSDAY/... Wednesday heigheights will be on the rise with high pressure building in at the surface as well delivering a dry and sunny day with comfortable temperatures, in the low to mid 70s. Winds will be lighter than today, but a bit breezy, out of the northwest. High cirrus clouds begin to move in during the afternoon, lowering and thickening after sunset ahead of an approaching warm front. This front extends from a low moving through the Great Lakes which will bring isentropically forced light to moderate rainfall into southern New England after midnight. As southwest winds advect in higher dewpoints in the lower 50s, this will likely keep low temps in the upper 40s to lower 50s.

Long Term - Thursday Night Through Tuesday
Highlights... * Slightly below normal temperatures Thursday, with some showers around.

* Warming up and becoming more humid Friday into this weekend, with potential for 90+ degree heat on Saturday.

* Cooler on Sunday with chance of thunderstorms.

* Even cooler early next week, with dry conditions expected.

A low pressure should move from the Great Lakes across northern New England Thursday, eventually pushing its associated fronts across southern New England. This front should not make it too far south, before it returns as a warm front late this week, courtesy of yet another low pressure moving into the Great Lakes. Unlike the first, this low pressure moves northeast into central Canada, opening the door for increased heat and humidity into this weekend. Attention then turns to a cold front, which is currently slated to arrive sometime Sunday. High pressure should then arrive for Monday into Tuesday.

Precipitation-wise, expecting showers to be around for at least Thursday morning, with a drying trend west-east during the afternoon and evening. The next best chance for showers will be late Saturday into Sunday ahead of a cold front. Expecting more showers with possible thunderstorms given the anticipated heat and humidity. The timing could be off a bit, as there is not a strong synoptic push to force this cold front more quickly towards our region. Thinking the greater risk is for Sunday at this time. Stay tuned to later forecasts.

Temperatures should rise rather quickly late this week. Starting out below normal Thursday, then above normal by Friday. Looking very summer-like this weekend, with some 90+ degree readings possible Saturday. That could continue into Sunday, depending on timing of a cold front. Temperatures should trend closer to normal early next week as a high pressure arrives.

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

High confidence through Wednesday night.

Main change to the forecast this evening will be to extend a Small Craft Advisory for the southern outer coastal waters for a few more hours. Gusty winds were still up around 25 kt, and seas will take a little longer to subside below 5 ft. The overall forecast remained largely on track.

Previous Discussion... Low pressure over southeast Quebec is resulting in WNW winds 15-25 kt, and this this will continue into Wed, highest wind near shore and during the afternoon hours. Thus, highest risk of SCA (Small Craft Advisory) winds will be near shore. Dry weather and good vsby thru Wed. Rain arrives after midnight. Seas 1-3 feet Wednesday night.

Outlook /Thursday Night through Sunday/... Wednesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers.
Thursday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers, patchy fog. Local visibility 1 to 3 nm.

Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Patchy fog.

Friday through Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Saturday: Winds less than 25 kt. Seas up to 5 ft.

Tides / Coastal Flooding
Despite high astronomical tides, offshore winds and rising pressure, surge values should be less than observed last night. Therefore not as confident on seeing any coastal flooding/minor inundation. So we will hold off on any headlines.

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

Small Craft Advisory until noon EDT today for ANZ250. Small Craft Advisory until 11am EDT this morning for ANZ251.