Casco Bay Marine Forecast
| Today...Sw Winds Around 5 Kt, Becoming S With Gusts Up To 20 Kt Late This Morning And Early Afternoon, Then Becoming Se With Gusts Up To 20 Kt Late. Seas 2 To 3 Ft. A Slight Chance Of Showers Late This Morning. Rain This Afternoon. |
| Tonight...S Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft. Showers In The Evening. |
| Sun...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. A Chance Of Showers In The Afternoon. |
| Sun Night...Sw Winds 5 To 10 Kt, Becoming W After Midnight. Seas 2 To 4 Ft. A Chance Of Showers. |
| Mon...Nw Winds Around 5 Kt, Becoming Sw In The Afternoon. Seas 2 To 4 Ft. A Chance Of Showers. |
| Mon Night...W Winds 5 To 10 Kt, Becoming Nw After Midnight. Seas 2 To 4 Ft. |
| Tue...Nw Winds 5 To 10 Kt. Seas 2 To 4 Ft. |
| Tue Night...Nw Winds 5 To 10 Kt, Diminishing To Around 5 Kt After Midnight. Seas 2 To 3 Ft. |
| Wed...W Winds Around 5 Kt, Becoming S 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 2 To 3 Ft. |
| Wed Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. Seas 2 To 3 Ft. A Chance Of Showers. |
| Area Forecast Discussion National Weather Service Gray ME 649am EDT Sat May 9 2026 .WHAT HAS CHANGED... No major changes to the going forecast. Still looking cooler than normal much of the next 7 days with periods of showery weather. Did however lower Probability of Precipitation a bit for Monday and main forcing for precipitation looks to remain to our south and east. .KEY MESSAGES... 1. Cool temperatures continue this morning with frost likely across much of the interior. 2. Expect steady rain for much of the forecast area through this afternoon, but some more showery activity is possible later, especially over southern New Hampshire and coastal Maine. Warmer temperatures return Sunday with some more scattered showers. 3. A few showery periods expected, especially Wednesday onward. Below normal temperatures most days. KEY MESSAGE 1 DESCRIPTION... Low temperatures this morning should be similar to yesterday morning with a bit more moisture. Thus, frost remains likely. The Frost Advisory over the interior portions of the coastal plain continues to be in good shape through 12z. Further inland, similar low temperatures are expected, but as noted in the previous forecast, headlines won't be issued here as the frost/freeze season based on climatology hasn't started yet. Lows should range from upper 20s and lower 30s north, to the mid to upper 30s over southern New Hampshire and coastal Maine. KEY MESSAGE 2 DESCRIPTION... Persistent troughing aloft continues across the northeast CONUS. The next shortwave rotates into the region this morning and medium to high chances (40 to 80 percent with the highest chances south) of steady rain should move into southern New Hampshire around 15z or so, gradually spreading north and east through the day. CAMs suggest that initial rainfall in the morning should generally be steady, but by late afternoon we could see some convective/showery activity across southern New Hampshire and coastal Maine. There is a non-zero chance for a few rumbles of thunder given 100 J/k of MUCAPE or so, but confidence is not high enough to include mention in the forecast at the moment. Most of the precipitation should move out to the east tonight, but some showers will likely linger through the overnight and into Sunday In general, rainfall totals shouldn't be overly significant. NBM probabilities suggest high chances for a widespread 0.25 inches but the highest chances for 0.50 inches or more are confined to the southern third of New Hampshire and coastal Maine. Any convective elements across the south could locally enhance some totals. The persistent southerly flow will lead to warmer temperatures on Sunday with highs ranging from the upper 50s and lower 60s north, to the mid and upper 60s elsewhere. The one exception will be across portions of the southern New Hampshire and southwest Maine where we could see a few lower 70s. Given unsettled flow, some isolated to scattered showers will remain possible through the day. KEY MESSAGE 3 DESCRIPTION... Upper level trough will remain over or near the northeast through at lot of the coming week. The main result will be below normal temperatures, and increasing chances for rain midweek onward. However, with no connection to richer moisture it appears that whatever rain fall during the week will be light and showery. We lowered Probability of Precipitation some for Monday as it appears the trough will remain flatter and farther south resulting in most precipitation remaining offshore except for some afternoon diurnal showers. Tuesday looks mainly dry as well. Thereafter, chances for showers increase through late week but uncertainty is high in placement. Marine Southwesterly flow gradually increases ahead of an approaching cold front, with SCA (Small Craft Advisory) conditions likely across the outer waters by late this afternoon lasting through Sunday morning. Winds and seas diminish with relatively light and winds expected through much of next week along with seas of 2-4ft. NOAA Gray/Portland ME Office - Watches - Warnings - Advisories ME...None. NH...None. Marine Small Craft Advisory from 6pm this evening to 2pm EDT Sunday for ANZ150-152-154. |
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