Nazare Big Wave Challenge Gets Yellow Alert, Could Run Saturday in Giant Waves
70-foot plus waves predicted for Portuguese big wave tow surfing competition.
Surf Forecasts:
Green Harbor surfForecast / Massachusetts / USA
48hr Weather and Surf, issued 12 pm Saturday 13 Dec 2025 ESTForecast update in hr min s Forecast update imminent
Green Harbor surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Green Harbor sea temperature is
7.7° C
(Which is normal for this time of year)How big are the waves at Green Harbor today?
The current surf forecast for Green Harbor at 7PM is: 0.1m 17s primary swell from a East direction and 0.1m 10s secondary swell from a East direction, 0.4m 3s secondary swell from a Southwest direction (forecast issued at 12:00pm December 13). An open ocean swell of 0.1m 5s is not directed at the surf break. The wind direction is predicted to be onshore.
| Time (EST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (13 Dec) | 0.5ft (0.1m) | 10s |
| Afternoon (13 Dec) | 0.5ft (0.1m) | 17s |
| Evening (13 Dec) | 1.5ft (0.4m) | 3s |
Table - waves today at Green Harbor. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Saturday 13 | Sunday 14 | Monday 15 | Tuesday 16 | |||||||||||||||||||||
| 10 AM | 1 PM | 4 PM | 7 PM | 10 PM | 1 AM | 4 AM | 7 AM | 10 AM | 1 PM | 4 PM | 7 PM | 10 PM | 1 AM | 4 AM | 7 AM | 10 AM | 1 PM | 4 PM | 7 PM | 10 PM | 1 AM | 4 AM | 7 AM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 10 | 18 | 17 | 17 | 3 | 10 | 16 | 16 | 15 | 9 | 15 | 15 | 15 | 7 | 7 | 7 | 7 | 6 | 6 | 5 | 5 | 4 | 10 | 10 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 2 | 6 | 6 | 6 | 3 | 2 | 5 | 5 | 4 | 1 | 4 | 4 | 4 | 255 | 176 | 179 | 102 | 78 | 51 | 20 | 13 | 11 | 8 | 8 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | on | on | on | on | on | on | cross- on | cross | cross- off | cross | cross- off | cross- off | cross | cross | cross | cross | cross | cross | cross- on | cross- on | cross- on | cross- on | cross- on | cross- on |
High Tide / height (m) | 6:30PM 2.57 | 7:00AM 2.75 | 7:30PM 2.49 | 7:51AM 2.76 | 8:25PM 2.44 | |||||||||||||||||||
Low Tide / height (m) | 12:14PM 0.33 | 12:34AM 0.32 | 1:14PM 0.32 | 1:26AM 0.41 | 2:09PM 0.29 | 2:16AM 0.47 | ||||||||||||||||||
Saturday 13 | Sunday 14 | Monday 15 | Tuesday 16 | |||||||||||||||||||||
| Sunrise | - | - | - | - | - | - | - | - | 7:01 | - | - | - | - | - | - | - | 7:03 | - | - | - | - | - | - | - |
| Sunset | - | - | 4:10 | - | - | - | - | - | - | - | 4:10 | - | - | - | - | - | - | - | 4:10 | - | - | - | - | - |
 |  | |  | | |  | |  | | | | |  |  | |  | | | | | | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 0 | 3 | 3 | 2 | 1 | 0 | 0 | 0 | -1 | -2 | 0 | -3 | -5 | -8 | -9 | -8 | -6 | -3 | -4 | -4 | -4 | -3 | -3 | -4 |
| Feels °C (?) | -7 | -5 | -4 | -4 | -5 | -6 | -5 | -5 | -7 | -9 | -8 | -13 | -16 | -19 | -19 | -18 | -16 | -12 | -13 | -12 | -12 | -11 | -10 | -10 |
- Map Icons:
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Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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