Marine Weather and Tide Forecast for South Duxbury, MA

KEY MESSAGES

- Mainly dry through Thursday Night with the exception of a few light snow showers this evening and overnight.

- Mostly dry through this weekend except a low chance for light nuisance snow Saturday. Temperatures make a return to near normal. Attention turns to late this weekend for a potential coastal storm, but forecast confidence remains low due to track uncertainty.

DISCUSSION
KEY MESSAGE 1...Mainly dry through Thursday Night with the exception of a few light snow showers this evening and overnight.

A mid level shortwave passes by southern New England late today into tonight. WHile this may be enough to trigger a few snow showers during this time, there is not much lift or humidity expected within the dendritic growth zone. Thus, really looking more like flurries over land. Over the coastal waters, could be a different story where some ocean effect processes can help to enhance the shower risk, which would be mainly a cold rain over the eastern MA coastal waters this evening.

Colder air moves over our region late tonight, so expecting low temperatures to be 5-7 degrees lower than what we saw this morning. This trend looks to continue through Thursday night.

KEY MESSAGE 2...Mostly dry through this weekend except a low chance for light nuisance snow Saturday. Temperatures make a return to near normal. Attention turns to late this weekend for a potential coastal storm, but forecast confidence remains low due to track uncertainty.

High pressure builds in over the Midwest/Mid-Atlantic regions later this week, finally pushing the arctic airmass offshore, bringing southern New England back to seasonable temperatures.
High temperatures rise into the mid to upper 30s, though overnight lows will still fall into the teens and low 20s, with some spots in the interior in the single digits.

Another upper-level low moves through Friday night, bringing chances for another quick shot of snow showers to southern New England early Saturday morning. The latest NBM guidance indicates probabilities 20- 30% chance of seeing 0.1" of snow across eastern MA as PWATs remain only about 75% of normal.
Heading into next week, guidance continues to indicate potential impacts from another storm moving across Texas and off the southeast Atlantic coast. Uncertainty in the timing and track only increases exponentially at that point, with the latest ensemble suite slowing the development of the low and increasing the spread of possible tracks. The Canadian ensemble indicates the closest track, passing just south of Nantucket, while the ECMWF ensemble shows the low passing south of the 40N/70W benchmark. The GFS ensemble struggles to resolve the low, with several members indicating the low may not remain organized as it moves offshore. Continued with low-end PoPs for Sunday night into Monday given the high amount of uncertainty at this point.

AVIATION /06Z THURSDAY THROUGH MONDAY/
Forecaster Confidence Levels...

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

Through 12Z...High confidence.

Last of the snow showers exit off Cape Cod and the Islands around 06Z. VFR conditions behind the snow showers. NW winds with gusts 20-25 kts.

Today...High confidence.

VFR. Breezy NW winds with gusts 20-22 kts. Gusts become lighter and less consistent in the afternoon. Few snow showers possible over outer Cape Cod after 11Z.

Thursday Night...High confidence.

VFR. NW winds 6-11 kts. Few gusts 18-20 kts.

KBOS Terminal...High Confidence.

KBDL Terminal...High Confidence.

Outlook /Friday through Monday/...

Friday: VFR.

Friday Night through Saturday: VFR. Slight chance SN.

Saturday Night through Sunday: VFR.

Sunday Night: VFR. Chance SN.

Washingtons Birthday: VFR. Chance RA, chance SN.

MARINE
Forecaster Confidence Levels...

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

Through Thursday Night...High Confidence.

Low pressure south of the Maritimes will swing an inverted trough over the coastal waters tonight. This could trigger scattered rain showers, at least until colder air arrives after midnight, when snow showers would be favored over the eastern coastal waters. Gusty NW winds persist as well. Toward daybreak areas of freezing spray are likely, especially the nearshore waters of MA and RI.

Outlook /Friday through Monday/...

Friday through Friday Night: Winds less than 25 kt. Seas locally approaching 5 ft.

Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of snow.

Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft.

Sunday: Winds less than 25 kt.

Sunday Night: Winds less than 25 kt. Chance of rain, chance of snow.

Washingtons Birthday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain, chance of snow, patchy fog.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 10 AM EST this morning for ANZ235- 237.
Small Craft Advisory until 7 AM EST Friday for ANZ250-254-255.
Small Craft Advisory until 7 PM EST this evening for ANZ256.