The Casco Bay Report
Wind, water and sky between Portland Head Light and Bailey Island — read off the instruments each hour and set down in plain language.
Thursday, October 15·Today’s reckoningCompiled 5:08 PM EDT
The State of the Bay
Taken at the hour from the harbour sensors, the offshore buoy and the forecast grid.
56°F
clear sky
feels 51°
The air
Dew point38°
Humidity50%
Cloud cover0%
Visibility80.9 mi
Barometer1021.3 mb
steady
Sun strength1.0
low
Fog0 of 100
unlikely
The wind
out of the north-northwest
Force 2 · Light breeze
NNW · 328°
offshore. Blowing off the land — water stays flat near shore, but it pushes small boats out to sea.
56°F
water — cold
The sea
Significant height1.0 ft
smooth
Dominant period8 s
Ground swell0.7 ft
at 8 seconds
Current at the entrance0.6 kt
ebbing, setting SE
Cold-shock response is real here. Wetsuit recommended; survival time 1–6 hours.
The Tide at Portland
AVERAGE RANGEPredicted from NOAA station 8418150 and checked against the measured water level. Heights are feet above mean lower low water.
7.8ft
and ebbing
-1.90 ft/hr
| Tide | Time | Height |
|---|---|---|
| Low | 9:13 PM | 0.8 |
| HighFri | 3:31 AM | 8.1 |
| LowFri | 9:19 AM | 1.9 |
| HighFri | 3:32 PM | 9.0 |
| LowFri | 10:03 PM | 1.2 |
| HighSat | 4:22 AM | 7.8 |
Next low9:13 PM
4h 5m from now
Range today8.5 ft
94% of the 9.1 ft mean
Against prediction+0.93 ft
Water is running high — wind setup
The Sun and the Moon
11h 2m of daylight, losing 3 min a dayComputed for 43°42′ N, 70°09′ W — the middle of the bay, between Long Island and Chebeague.
The sun
First light civil dawn | 6:26 AM |
Sunrise golden until 7:34 AM | 6:54 AM |
Highest 37.6° above the horizon | 12:26 PM |
Golden hour the good light | 5:17 PM |
Sunset | 5:57 PM |
Last light full dark at 7:32 PM | 6:25 PM |
The sun stands 7.7° up, bearing 250° — wsw of you.
The moon
Waxing Crescent
23.2% lit · 4.7 days old
Rises12:19 PM
Sets—
Next fullOct 25
Next newNov 9
Feeding periods47
The old solunar reckoning: fish move hardest when the moon is on the meridian — overhead or underfoot — and again at its rising and setting. Lay a major period over a running tide and that is your hour.
| Period | From | To |
|---|---|---|
| Moon underfootmajor | 3:00 AM | 5:00 AM |
| Moonriseminor | 11:49 AM | 12:49 PM |
| Moon overheadmajor | 3:25 PM | 5:25 PM |
Notices to Mariners
1 in forceWhat would catch you out today, and what is worth going out for.
Small Craft Advisory
Minor · until 12:00 AM EDTSmall Craft Advisory issued October 15 at 2:27PM EDT until October 18 at 12:00AM EDT by NWS Gray ME
Penobscot Bay; Casco Bay
Small Craft Advisory
Small Craft Advisory issued October 15 at 2:27PM EDT until October 18 at 12:00AM EDT by NWS Gray ME
Small-craft conditions
Reaching gusts to 33 kt around 2:00 PM tomorrow. That is the NWS advisory threshold for these waters.
Fog likely
Elevated fog risk from 4:00 PM tomorrow to 5:00 PM tomorrow. Warm air over cold water — the classic Casco Bay setup. Carry radar and sound your horn.
Wind against tide
Around 6:00 AM tomorrow the breeze opposes the current. Seas will stand up short and steep — worse than the 0.9 ft height suggests, especially at the harbor entrance.
Wind peaks
S 24 kt, gusts 35 around 3:00 PM tomorrow.
Water 56°F — cold
Cold-shock response is real here. Wetsuit recommended; survival time 1–6 hours.
Evening golden hour
Starts 5:17 PM, sunset 5:57 PM, civil dusk 6:25 PM. Day length is shrinking by 3 min a day right now.
Best window 7:00 AM tomorrow
S 16 kt, 1.1 ft seas, ebb tide. Best combination of breeze and sea state in the next 24 hours.
Hour by Hour
The next day and night, read off the forecast grid and joined to the tide and the current at the harbour entrance.
| Hour | Weather | Air | Wind | Gust | Sea | Per. | Tide | Set | Curr. | Rain | Vis. | Fog |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| now | Clear sky | 56° | NNW 4 | 8 | 0.9 | 8s | 7.1 | ebb | 0.6 | 0% | 81 | 0 |
| 6 PM | Partly cloudy | 56° | NW 5 | 8 | 0.8 | 8s | 5.1 | ebb | 0.9 | 0% | 74 | 0 |
| 7 PM | Partly cloudy | 56° | NNW 4 | 8 | 0.8 | 9s | 3.0 | ebb | 0.9 | 0% | 59 | 0 |
| 8 PM | Overcast | 54° | N 5 | 8 | 0.7 | 9s | 1.5 | ebb | 0.7 | 0% | 47 | 0 |
| 9 PM | Overcast | 54° | N 9 | 11 | 0.7 | 9s | 0.8 | low | 0.5 | 0% | 48 | 0 |
| 10 PM | Overcast | 53° | NE 11 | 13 | 0.7 | 9s | 1.0 | flood | 0.2 | 0% | 49 | 9 |
| 11 PM | Overcast | 53° | ENE 11 | 14 | 0.7 | 9s | 2.1 | flood | 0.1 | 0% | 55 | 9 |
| 12 AMFri | Overcast | 52° | ENE 10 | 12 | 0.7 | 9s | 3.8 | flood | 0.4 | 0% | 54 | 9 |
| 1 AM | Overcast | 52° | E 9 | 10 | 0.7 | 9s | 5.7 | flood | 0.5 | 0% | 48 | 9 |
| 2 AM | Overcast | 53° | ESE 8 | 10 | 0.7 | 9s | 7.2 | flood | 0.4 | 0% | 51 | 9 |
| 3 AM | Overcast | 54° | SSE 11 | 12 | 0.8 | 8s | 8.0 | high | 0.2 | 1% | 58 | 0 |
| 4 AM | Overcast | 54° | SSE 13 | 15 | 0.8 | 7s | 8.0 | high | 0.0 | 1% | 56 | 0 |
| 5 AM | Overcast | 55° | S 14 | 15 | 0.9 | 7s | 7.2 | ebb | 0.3 | 8% | 55 | 0 |
| 6 AM | Overcast | 55° | S 15 | 18 | 0.9 | 6s | 5.8 | ebb | 0.7 | 11% | 50 | 0 |
| 7 AM | Overcast | 56° | S 16 | 19 | 1.1 | 6s | 4.1 | ebb | 0.8 | 14% | 46 | 0 |
| 8 AM | Light drizzle | 55° | S 19 | 23 | 1.1 | 5s | 2.7 | ebb | 0.7 | 41% | 43 | 0 |
| 9 AM | Light drizzle | 54° | S 21 | 26 | 1.4 | 5s | 1.9 | low | 0.4 | 64% | 41 | 0 |
| 10 AM | Drizzle | 54° | SSE 23 | 28 | 1.8 | 4s | 2.1 | flood | 0.2 | 66% | 20 | 0 |
| 11 AM | Heavy drizzle | 53° | SSE 23 | 30 | 2.1 | 4s | 3.0 | flood | 0.1 | 80% | 18 | 0 |
| 12 PM | Rain | 53° | SSE 24 | 29 | 2.4 | 4s | 4.6 | flood | 0.4 | 75% | 9.2 | 0 |
| 1 PM | Rain | 54° | SSE 24 | 30 | 2.6 | 4s | 6.4 | flood | 0.5 | 76% | 6.9 | 21 |
| 2 PM | Overcast | 55° | S 23 | 33 | 2.9 | 4s | 8.0 | flood | 0.4 | 74% | 25 | 15 |
| 3 PM | Light drizzle | 56° | S 24 | 35 | 3.0 | 4s | 8.8 | high | 0.2 | 60% | 25 | 22 |
| 4 PM | Fog | 56° | S 19 | 24 | 3.1 | 5s | 8.9 | high | 0.0 | 46% | 0.2 | 96 |
| 5 PM | Fog | 56° | SSW 10 | 15 | 3.2 | 5s | 8.1 | ebb | 0.3 | 22% | 0.4 | 96 |
Sea in feet, period in seconds, tide in feet above mean lower low water, current in knots at the harbour entrance, visibility in miles, fog on a scale of one hundred.
From the Weather Service
The official word, printed as issued. Where this page disagrees with the bulletin, believe the bulletin.
Coastal Waters Forecast
National Weather Service · Gray, Maine
Zone ANZ153 — Casco Bay
National Weather Service · Gray, Maine
Zone ANZ153 — Casco Bay
Issued 2:37 PM EDT
.SYNOPSIS... High pressure crosses the waters tonight. Low pressure approaches from the Great Lakes tonight, passing north of the waters on Friday. A cold front crosses tomorrow night. Winds will shift to northwesterly and become gusty again. Gale force wind gusts are possible Saturday into Saturday night. High pressure returns on Sunday, and prevails through early next week.
.Tonight... N winds around 5 kt, becoming E after midnight, then becoming SE towards daybreak. Seas around 2 ft this evening, then 1 foot or less.
.Fri... S winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 4 ft. Rain. Vsby 1 to 3 NM.
.Fri Night... SW winds 10 to 15 kt with gusts up to 20 kt, becoming NW 15 to 20 kt with gusts up to 30 kt after midnight. Seas 2 to 4 ft. Showers in the evening.
.Sat... NW winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 4 ft.
.Sat Night... NW winds 15 to 20 kt with gusts up to 30 kt, diminishing to 5 to 10 kt with gusts up to 20 kt after midnight. Seas 2 to 4 ft.
.Sun... NW winds 5 to 10 kt, becoming W in the afternoon. Seas around 2 ft in the morning, then 1 foot or less.
.Sun Night... SW winds 5 to 10 kt. Seas 1 foot or less, then around 2 ft after midnight.
.Mon... SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft.
Ashore
This Afternoon
Mostly sunny, with a high near 58. Northwest wind around 5 mph.
Tonight
Mostly cloudy, with a low around 49. Northeast wind 5 to 10 mph. New rainfall amounts less than a tenth of an inch possible.
Friday
Rain before 5pm, then a chance of rain showers. Cloudy, with a high near 63. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Friday Night
Rain showers before 10pm. Mostly cloudy, with a low around 43. West wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 90%.
Saturday
Partly sunny, with a high near 49. Northwest wind around 20 mph, with gusts as high as 30 mph.
Saturday Night
Mostly clear, with a low around 37.
The Week Ahead
Wave heights run out past two and a half days — beyond that the marine model has nothing honest to say, and the column is left blank.
| Day | Weather | High | Low | Wind | Gust | Sea | Rain | Moon | High water |
|---|---|---|---|---|---|---|---|---|---|
| TodayOct 15 | Overcast | 56° | 51° | NNW 18 | 30 | 1.2 | 0% | Waxing Crescent23% | 2:44 AM · 2:45 PM |
| FriOct 16 | Rain | 59° | 52° | S 24 | 35 | 3.2 | 80% | Waxing Crescent32% | 3:31 AM · 3:32 PM |
| SatOct 17 | Overcast | 58° | 37° | NW 23 | 31 | 3.1 | 11% | Waxing Crescent41% | 4:22 AM · 4:25 PM |
| SunOct 18 | Clear sky | 57° | 34° | SW 6 | 12 | 1.1 | 1% | First Quarter50% | 5:17 AM · 5:22 PM |
| MonOct 19 | Clear sky | 60° | 42° | SSW 9 | 14 | — | 5% | Waxing Gibbous60% | 6:13 AM · 6:20 PM |
| TueOct 20 | Overcast | 62° | 44° | N 8 | 25 | — | 5% | Waxing Gibbous69% | 7:09 AM · 7:17 PM |
| WedOct 21 | Overcast | 56° | 44° | NNE 12 | 25 | — | 1% | Waxing Gibbous78% | 8:00 AM · 8:12 PM |
From the Buoys and Gauges
Measured, not modelled. These are the actual instruments in the water, with the age of each reading.
| Station | Distance | Wind | Sea | Per. | Swell | Water | Air | Age |
|---|---|---|---|---|---|---|---|---|
| Portland Harbour station 8418150, on the waterfront | — | WNW 6 | — | — | — | 55.8° | 59.4° | 8m |
| Portland Lightship Buoy buoy 44007 — 12 nm southeast of portland — the bay's reference buoy | 10.5 nm | NW 10 | 1.0 | 8s | 0.7 SSE | 55.2° | 57.4° | 38m |
| Western Maine Shelf buoy 44030 — wind and air temperature on the western shelf | 33.5 nm | ENE 4 | — | — | — | 56.8° | 56.1° | 1h 38m |
| Jeffreys Ledge buoy 44098 — offshore to the south — shows swell arriving from the gulf | 54.2 nm | — | 2.3 | 4s | 0.7 ESE | 55.2° | 55.6° | 38m |
| Jonesport, Maine buoy 44027 — down east — early warning for weather tracking southwest | 128 nm | NW 14 | 3.0 | 4s | 1.0 SW | 53.8° | —° | 38m |
Freshwater into the bay
Presumpscot459 cfs
enters at Falmouth
Royal85 cfs
enters at Yarmouth
Androscoggin1,940 cfs
enters at Merrymeeting Bay
After rain the plume freshens and clouds the top few feet near the river mouths, and carries stormwater down with it for a day or two.
Air and sky
Air quality36
good
GeomagneticKp 2.3
no northern lights tonight
Casco Bay lies near 53° magnetic latitude. It takes Kp 6 or better before the lights clear the horizon, and you want to be off away from Portland’s glow — Chebeague, Cliff, or the north shore of Bailey.
Last reading 2:00 PM EDT