Boston Harbor Marine Forecast
|Tonight...S Winds Around 10 Kt With Gusts Up To 20 Kt. Waves Around 2 Ft. Showers Likely With A Slight Chance Of Tstms.|
|Mon...Sw Winds 10 To 15 Kt. Gusts Up To 20 Kt In The Afternoon. Waves 1 Foot Or Less, Then Around 2 Ft In The Afternoon.|
|Mon Night...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. Waves Around 2 Ft In The Evening, Then 1 Foot Or Less.|
|Tue...Sw Winds 5 To 10 Kt. Waves 1 Foot Or Less.|
|Tue Night Through Wed Night...Nw Winds 5 To 10 Kt. Waves 1 Foot Or Less.|
|Thu Through Fri Night...S Winds 5 To 10 Kt. Winds And Waves 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
239pm EDT Sunday September 25 2022
A warm front will provide a threat for a few strong to severe thunderstorms towards the south coast into this evening. A shallow cold front then follows with drier conditions from west to east after midnight. Pleasant temperatures follow Monday and Tuesday with mainly dry weather, other than a spot shower or two. Temperatures slowly cool off mid week into early next weekend. High uncertainty if moisture from Ian eventually impacts us next weekend or remains to our south.
Near Term - Through Tonight
* A few strong to severe thunderstorms possible later this evening
Not much change to the overall pattern and forecast concerns from earlier forecasts. A warm front remained to our south early this afternoon. How far north this front can get into southern New England this evening will be a critical component to the forecast. The greatest severe weather threat will be located along and south of this boundary this evening. At this time, still thinking the greatest thunderstorm threat will towards the immediate south coast of New England and the adjacent coastal waters. Instability should be ramping up over the next few hours. Most of theNear Term - Rest Of Today Through Tonight
ance is hinting at strong bulk shear of 40-50 kt arriving this evening as well.
Eventually, a cold front associated with a low pressure near the Great Lakes will arrive in southern New England. Expecting this front to take all night to reach the coast, meaning at least a chance for showers for most through midnight, then mostly over the eastern half of our region after midnight.
Short Term - Monday Through Monday Night
Looking for more sunshine to develop during Monday, at least until diurnal clouds start to develop with a persistent cold pool over the Great Lakes. Scattered showers are also expected, mainly towards western MA, which will be closer to the core of the cold pool(a region of relatively cold air) aloft. Not looking like much of a thunderstorm risk at this time.
Clouds and showers should dissipate Monday evening, leaving dry conditions for most through Monday night.
Expecting temperatures to be slightly higher tomorrow with more sunshine during the day. Near to slightly above normal temperatures expected Monday night.
Long Term - Tuesday Through Sunday
Highlights... * A spot shower or two Tuesday, otherwise expect dry conditions through Friday. At this time it is uncertain if the moisture from Ian makes it to southern New England for next weekend.
* Warm Tuesday, seasonable Wednesday, then below normal temperatures for Thursday into next weekend.
Tuesday and Wednesday:
An anomalous mid-level trough across the Great Lakes region on Tuesday will deamplify and move east on Wednesday. Early morning Tuesday a weak surface low exits the waters east of southern New England which allows for a few spot morning showers across eastern Massachusetts, Cape Cod, and the Islands. A secondary low moves northeast from Montreal to Quebec Tuesday into Wednesday as well with a trailing cold front. The lack of deeper moisture/forcing will generally result in a dry frontal passage; other than perhaps a brief spot shower or two. PWATs (Precipitable Waters) are generally less than 1/2 inch.
Southwest winds aloft on Tuesday will advect a warmer air mass into the region, ahead of the front, with temperatures reaching into the low and mid-70s. Slightly cooler in the 60s for elevated communities across western Franklin/Hampshire/and Hampden. Post front winds aloft become west and results in seasonable highs in the mid-60s to near 70 degrees for metrowest Boston.
Thursday and Friday:
Global ensembles continue to support a dry conditions throughout the remainder of the work week with an area of high pressure extending across much of the northeastern United States. In addition, the global ensembles are still showing a signal for below average afternoon temperatures. Therefore, high temperatures mainly are in the 60s Thursday and Friday. The dry airmass in place will result in low temps in the 40s with some 30s in the outlying locations. So would expect to see some bouts of frost by the end of the week.
Saturday and Sunday:
Forecast confidence diminishes considerably by next weekend. Main issue will be Ian and/or its remnants to our south. There remains high uncertainty on whether or not the moisture from Ian will eventually get pulled northward into southern New England. This is quite evident in the latest individual ensemble members from the GEFS/EPS guidance. Some of the members keep the rainfall to our south, while others bring it up into our region. There is not much more that we can say at this time, but we will need a few more days to have a better idea.
Forecaster Confidence Levels:
Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.
A warm front is expected to move into southern New England and across the waters this evening. A cold front should move from west to east after midnight into Monday morning. Gusty SW winds up to 30 kt for some waters, with rough seas developing across the southern coastal waters. Small Craft Advisories continue into Monday. expecting a period of rough seas later tonight for the coastal waters east of Boston later this evening. Winds and seas gradually diminish Monday night.
Outlook /Tuesday through Friday/... Tuesday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers.
Tuesday Night: Winds less than 25 kt. Seas up to 5 ft.
Wednesday through Wednesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.
Small Craft Advisory from 5pm this afternoon to 4am EDT Monday for ANZ231-250. Small Craft Advisory until 10pm EDT Monday for ANZ232>234. Small Craft Advisory until 4am EDT Tuesday for ANZ235-237. Small Craft Advisory until 8am EDT Tuesday for ANZ254>256.