Marine Weather Net

Casco Bay Marine Forecast


TODAY

SW
WINDS
5 - 10
KNOTS

TONIGHT

SW
WINDS
10 - 15
KNOTS

TUE

SW
WINDS
5 KNOTS

TUE NIGHT

S
WINDS
5 KNOTS

The Marine Weather Forecast In Detail:
ANZ153 Forecast Issued: 255 AM EDT Mon Mar 09 2026

SMALL CRAFT ADVISORY IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
Today...Sw Winds 5 To 10 Kt, Becoming S 15 To 20 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft.
Tonight...Sw Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft.
Tue...Sw Winds Around 5 Kt. Seas 2 To 3 Ft.
Tue Night...S Winds Around 5 Kt, Becoming Ne After Midnight. Seas Around 2 Ft.
Wed...Ne Winds 10 To 15 Kt, Becoming E 15 To 20 Kt In The Afternoon. Seas 2 To 3 Ft. Rain Likely.
Wed Night...Se Winds 15 To 20 Kt, Becoming S After Midnight. Seas 3 To 5 Ft. Rain Likely.
Thu...Sw Winds 15 To 20 Kt, Becoming W In The Afternoon. Gusts Up To 30 Kt. Seas 3 To 5 Ft. Rain Likely. A Chance Of Snow In The Afternoon.
Thu Night...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft. A Chance Of Snow In The Evening.
Fri...W Winds 10 To 15 Kt, Becoming Sw 15 To 20 Kt In The Afternoon. Seas 2 To 4 Ft.
Fri Night...S Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft. Snow And Rain Likely. Vsby 1 Nm Or Less.
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Area Forecast Discussion
National Weather Service Gray ME
237am EDT Monday Mar 9 2026

.WHAT HAS CHANGED... No significant changes with this forecast package update. Temperatures have trended warmer today and Tuesday.

.KEY MESSAGES... 1. Mostly dry weather combined with temperatures climbing into the upper 50s to 60s will act to significantly reduce snowpack through Tuesday, with modest dewpoints keeping melt controlled. Shifts in river ice will have to be monitored, but the flood risk remains low at this time.

2. The pattern turns more unsettled by midweek as cooler air begins to work back into Northern New England. A battle between warm and cool air then continues through the end of the week and into the weekend with more chances for precip.

KEY MESSAGE 1 DESCRIPTION... Deep west-southwest flow will allow for high temperatures to climb +20F or more degrees above normal today through Wednesday. Temperatures will rise to around +10C at 925 mb with favorable mixing allowing highs this afternoon to push well into the 60s south of the mountains. An onshore component of surface winds will limit the warmth near the mid coast. Dewpoints will rise above freezing after day break but will mainly remain at or below 40F through this afternoon. A mix of sun and clouds will transition to mostly sunny skies this afternoon with the combination of these elements resulting in controlled snowmelt.

Temperatures and dewpoints remain mild tonight leading to even warmer conditions during the day Tuesday. Deep southwest flow along with mostly sunny skies will bring high temperatures into the mid to upper 60s across much of the area. The exceptions will be near the Canadian Border with a sagging cold front will keep temperatures cooler and near the Mid Coast where a light seabreeze will develop. Dewpoints will be higher than today reaching the low 40s that will continue to allow for significant, but controlled snowmelt with the lack of precipitation. During this melt period will continue to keep a close eye on river rises due to snowmelt and ice movement while the flood risk remains low.

KEY MESSAGE 2 DESCRIPTION... The cold tries to make its return on Wednesday in the form of a backdoor cold front pressing in from the northeast. Southwest New Hampshire stands a chance to eek out one more warm day, but the forecast is steadily trending colder for the rest of the forecast area. As the NBM gradually catches up to the back door front and cold air damming pattern, the forecast is likely to continue to trend colder over the coming days.

At the same time, a wave of low pressure rides eastward on Wednesday, bringing the potential for a wintry mix across at least northern areas. Freezing rain and sleet would be the most likely forms of precip, with more scattered shower activity further south. The best forcing looks to be on the north side of the front, focusing the higher Quantitative Precipitation Forecast amounts across northern locations.

The low likely crosses New England on Thursday, with a brief chance to break into the warm sector for a few hours Thursday morning, before the cold front crosses in the afternoon hours. Cooler air then returns behind the front for Friday and the weekend, with attention then turning to the next potential system on Friday night and Saturday.

Marine
South to southwest flow along with elevated seas will bring SCA conditions today with winds peaking this afternoon around 30 kts. Winds and seas diminish tonight into Tuesday morning.

A backdoor cold front crosses the waters Tuesday night and Wednesday, with northeasterly winds to SCA (Small Craft Advisory) or low end gale strength. Low pressure tracks eastward Wednesday, shifting winds to south late Wednesday night. Westerly gales are then possible behind the system on Thursday into Thursday night. Another system is then possible by Saturday.

NOAA Gray/Portland ME Office - Watches - Warnings - Advisories
ME...None. NH...None.

Marine
Small Craft Advisory until 7am EDT Tuesday for ANZ150-152. Small Craft Advisory from 2pm this afternoon to 2am EDT Tuesday for ANZ151-153. Small Craft Advisory until 2am EDT early this morning for ANZ153. Small Craft Advisory until 2am EDT Tuesday for ANZ154.