Boston Harbor Marine Forecast
| Tonight...Sw Winds 10 To 15 Kt. Waves Around 2 Ft. |
| Fri...W Winds 5 To 10 Kt, Becoming S 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Waves 1 Foot Or Less, Then Around 2 Ft In The Afternoon. |
| Fri Night...Sw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Waves Around 2 Ft. Rain. |
| Sat...Nw Winds 10 To 15 Kt. Waves Around 2 Ft. A Chance Of Rain In The Morning. |
| Sat Night...N Winds Around 10 Kt, Becoming W After Midnight. Waves 1 Foot Or Less. |
| Sun...S Winds Around 10 Kt. Waves 1 Foot Or Less. A Chance Of Rain In The Afternoon. |
| Sun Night...S Winds 10 To 15 Kt, Becoming E 15 To 20 Kt After Midnight. Waves Around 2 Ft. Rain Likely. |
| Mon...N Winds 15 To 20 Kt. Waves Around 2 Ft. Rain Likely. |
| Mon Night Through Tue Night...Sw Winds 15 To 20 Kt. Waves Around 2 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. |
| Area Forecast Discussion National Weather Service Boston/Norton MA 743pm EDT Thu Mar 19 2026 .WHAT HAS CHANGED... No significant changes were made to the forecast during this update. .KEY MESSAGES... - Mild and breezy conditions Friday ahead of an approaching frontal system. Periods of rain develop Friday night as the front pushes through but we're not expecting a washout at this time. - Breezy and unsettled through early next week. Another round of showers Sunday night into Monday. Cooler, but still near normal, temperatures expected Monday through mid-week. KEY MESSAGE 1...Mild and breezy conditions Friday ahead of an approaching frontal system. Periods of rain develop Friday night as the front pushes through but we're not expecting a washout at this time. Fairly strong frontal wave dives SE from Ontario later Friday bringing a period of breezy and rainy conditions. Breezy weather will be driven by a robust south westerly low level jet that will strengthen to 45-55 knots by the evening. Otherwise, mostly sunny conditions should prevail at least during the morning hours Friday. Expect thickening mid and high level clouds Friday afternoon as well as an increasing southwest breeze. Wind speeds increase around 10-15 mph and gusts in the 25 to 35 mph range, with the higher end of that range more confined to Cape Cod and the Islands which typically gusts pretty well with SW flow (tempered by the cooler water temps). Should be a fairly mild day with highs in the lower 50s in most areas and perhaps as high as the upper 50s in the CT and Merrimack river valleys. Cooler with max temps in the upper 40s over the south coast, Cape and Islands due to persistent SW flow over the waters. Increasing chance for POPs Friday evening and overnight as a broken band of rain and showers moves from NW to SE. This will also lead to decreasing SW wind gusts as the column stabilizes. As it does so, it will act on a modest PWAT (Precipitable Water) plume increasing to around 0.75-0.8 inches, which is really not that impressive. Kept Probability of Precipitation at high Likely to lower Categorical, although this doesn't look to be a significant precip-maker, with ensemble Quantitative Precipitation Forecast probs still indicating low (< 30%) probs of rainfall totals greater than 0.50". The NBM has about a 50-50 chance of seeing greater than 0.20 inches of rain. Given stable thermodynamics and only modest PWATs (Precipitable Waters) to work with, the rainfall probs seem reasonable. May have to watch for a slowing frontal zone though, as the orientation of the front becomes nearly parallel to the 500 mb height contours, which could result in lingering showers into early Saturday morning. KEY MESSAGE 2...Breezy and unsettled through early next week. Another round of showers Sunday night into Monday. Cooler, but still near normal, temperatures expected Monday through mid-week. We will still be dealing with a pesky front late Sunday into Monday as it gets hung up by a low pressure moving over the Great Lakes. This low pressure is anticipated to move just south of New England late Sunday night into Monday, finally dragging this front away from our region. While there is a chance for some rainfall Sunday afternoon, we're thinking the majority of precipitation will be Sunday night. It's then a race between the precipitation leaving and colder air trying to overspread southern New England. At this time, there does appear to be a brief window where light snow is possible late Sunday night into Monday morning. That said, this would be mainly for areas along and north of Route 2 in MA, but could also impact the east slopes of the Berkshires and Worcester Hills. Given the brief duration of any snow, little to no snow accumulation is expected. High pressure over the central Appalachians Tuesday then takes over our weather for a brief time, before moving offshore from the Mid Atlantic coast Wednesday. Still not certain about the impacts from another cold front some time late Wednesday into Wednesday night. This front looks to be moisture-starved, so thinking mainly clouds. The next chance for rainfall could be Thursday as a warm front tries to pass us by. Above normal temperatures Sunday trend to below normal Monday and Tuesday. Looking like near normal temperatures should return for Wednesday and Thursday. Marine Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Winds and seas will remain below marine headline thresholds through tonight. SE winds today around 10-15 kt to shift to S and then SW tonight into early Friday. Seas 4 ft or less on all waters. SCA (Small Craft Advisory) issued for the outer waters from 00z Sat thru 00z Sun. SCA in effect from 00z-09z Sat for Buzzards, Nantucket, and Cape Cod Bays. While a few gale-force gusts are possible, shallow mixing depth over the cooler marine boundary layer likely results in gusts in the 25-30 kt range. Areas of rain and showers likely result in areas of reduced visibility. Outlook /Friday Night through Tuesday/... Friday: Low risk for Small Craft Advisory winds with local gusts up to 30 kt. Seas locally approaching 5 ft. Friday Night: Moderate risk for Small Craft Advisory winds with local gusts up to 30 kt. Seas up to 5 ft. Chance of rain. Saturday: Winds less than 25 kt. Seas up to 5 ft. Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain. Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Rain likely. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain. Monday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Tuesday: Winds less than 25 kt. Local rough seas. NOAA Boston MA Office: Watches - Warnings - Advisories CT...None. MA...None. RI...None. Marine Small Craft Advisory from 8pm Friday to 5am EDT Saturday for ANZ231>235-237. Small Craft Advisory from 2pm Friday to 8pm EDT Saturday for ANZ250-254>256. |
Boston MA Radar
Northeast Radar
East Coast Satellite