East of Ipswich Bay and the Stellwagen Bank Marine Sanctuary Marine Forecast
| This Afternoon...S Winds 5 To 10 Kt. Seas 3 To 5 Ft. Wave Detail: Se 5 Ft At 12 Seconds And Sw 2 Ft At 3 Seconds. |
| Tonight...Sw Winds 5 To 10 Kt, Becoming Nw After Midnight. Seas 3 To 5 Ft. Wave Detail: Se 5 Ft At 10 Seconds And Sw 1 Foot At 3 Seconds. Patchy Fog. A Chance Of Showers. Vsby 1 To 3 Nm. |
| Wed...Ne Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 3 To 5 Ft. Wave Detail: Se 5 Ft At 12 Seconds And E 3 Ft At 7 Seconds. Patchy Fog. A Chance Of Showers. Vsby 1 To 3 Nm. |
| Wed Night...E Winds 10 To 15 Kt. Gusts Up To 20 Kt In The Evening. Seas 3 To 5 Ft. Wave Detail: Se 4 Ft At 11 Seconds And Ne 3 Ft At 5 Seconds. A Chance Of Showers In The Evening, Then Showers Likely After Midnight. Patchy Fog In The Evening With Vsby 1 To 3 Nm. |
| Thu...Se Winds Around 10 Kt. Seas 3 To 4 Ft. Wave Detail: Se 3 Ft At 10 Seconds And Se 2 Ft At 4 Seconds. Showers Likely. Vsby 1 To 3 Nm In The Afternoon. |
| Thu Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Wave Detail: E 3 Ft At 6 Seconds And Se 3 Ft At 10 Seconds. Showers. Vsby 1 To 3 Nm. |
| Fri...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Showers Likely. |
| Fri Night Through Sat Night...Sw Winds 5 To 10 Kt. Seas 2 To 3 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. |
| Area Forecast Discussion National Weather Service Boston/Norton MA 220pm EDT Tuesday September 23 2025 Synopsis Warm and humid conditions this afternoon and evening with scattered showers and a few thunderstorms lingering into tonight as a front moves into the region. Much cooler Wednesday with risk of showers continuing, then another period of widespread showers and a few thunderstorms Thursday into Thursday night as a frontal system moves into the region. Unsettled weather pattern may linger into Friday, then gradual improvement this weekend. Above normal temperatures and increasing humidity return Thursday night into the weekend. Near Term - Through Wednesday Key Messages... * Warm and humid today with scattered afternoon showers and t-storms in the interior. These continue through the overnight hours. Moist SW flow continues to advect a warm and humid airmass into the region leading to plenty of cloud cover mixing with the sunshine with showers on our doorstep. These breaks of sun the warm airmass lead to highs in the upper 70s and low 80s; this with the dewpoints in the mid to upper 60s will contribute to marginal instability, with CAPE values on the order of around 500 J/kg. Moisture is plentiful as well with those dewpoints and PWATs (Precipitable Waters) approaching 2 inches and lift will arrive in the form of a weak cold front dropping south. Severe parameters are not impressive given the weak lift, moderate CAPE, and bulk shear of 25-30 kts. Even so, there is enough that an isolated strong storm is possible. Hi-res guidance continues to point to heavy downpours being possible as well which could drop 1-2 inches of rain in an hour in a localized area. Overall, not expecting these showers and t-storms to be very impactful. Unsettled weather continued to move east through the region overnight as the front stalls with the threat for passing downpours continuing into Wednesday. Wednesday we'll see the bulk of the overnight showers moving offshore early as the front sinks south and weak mid level ridging moves overhead. However, high pressure building over the maritimes will direct cool, moist NE flow into the region keeping low level moisture overhead in the form of thick clouds and light rain or drizzle. Forecast soundings show a nearly saturated atmosphere up to at least 850 mb in much of SNE. This combined with another approaching shortwave and moisture plume later Wednesday will mean continued shower chances all day. Instability should stay south of the region for the most part, but can't rule out it clipping part of CT leading to a rumble of thunder. Temperature-wise, the cloudcover and northeast flow will mean highs quite a bit cooler than today, in the mid/upper 60s to 70F. The warmest location would be parts of the CT valley where downsloping flow helps them reach the low to mid 70s. Overnight elevated dewpoints will keep lows mild, in the low to mid 60s. Short Term - Wednesday Night Key Messages... * Showers with low temperatures in the upper 50s and low 60s. More of the same is expected on Wednesday night with expanding coverage of showers as the mid level trough gets closer, increasing lift acting on a 1.5-2" PWAT (Precipitable Water) plume. Low temperatures only dip into the upper 50s and low 60s. Long Term - Thursday Through Monday Key Messages: * Another round of more widespread showers and a few thunderstorms Thu into Thu night * Warm weather Fri through this weekend, but unsettled Fri and possibly Sat Still looking unsettled late this week across southern New England. A mid level trough is nearby, but the heigheights are not anything unusual for this time of year. That said, this trough will keep a surface low pressure nearby as well, taking its time to move from the Great Lakes into eastern Canada Thursday into Friday. The cold front associated with this low pressure is still not expected to pass by our region until sometime Friday afternoon. Even then, this front could stall just off the coast, keeping at least a risk for some showers towards the south coast Saturday. High pressure should finally bring an end to our periodic wet weather, but that is not likely until sometime on Sunday. The latest NationalBlend had 80-90% probabilities for at least 1 inch of rainfall int he 72-hours ending 8pm Friday across most of southern New England. Slightly lower probabilities of 60-80% across RI and southeast MA during this same time. There were even modest probabilities, 40-60% for more than 2 inches of rainfall for an area from northwest CT into south central MA. Not entirely convinced the location of the heavier rainfall is correct, but the potential is there. Given our recent dry conditions, we really could use whatever rainfall we can get. Expecting temperatures to be near to slightly above normal for this portion of the forecast. Marine Forecaster Confidence Levels... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Wednesday night...High Confidence. SCA (Small Craft Advisory) for outer waters into Wednesday for marginal seas. Winds expected to remain below SCA. SW gusts to 20 kt today, then shifting to E-NE 10- 20 kt Wed, diminishing a bit overnight. Outlook /Thursday through Saturday/... Wednesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Rain showers likely. Thursday Night through Friday: Winds less than 25 kt. Seas locally approaching 5 ft. Rain showers likely, slight chance of thunderstorms. Friday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. Saturday: Winds less than 25 kt. Chance of rain showers. NOAA Boston MA Office: Watches - Warnings - Advisories CT...None. MA...None. RI...None. Marine Small Craft Advisory until 2am EDT Wednesday for ANZ235-237. Small Craft Advisory until 8pm EDT Wednesday for ANZ250. Small Craft Advisory until 2pm EDT Wednesday for ANZ254>256. |
Boston MA Radar
Northeast Radar
East Coast Satellite