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:
Amatu surfForecast / Chiba / Japan
48hr Weather and Surf, issued 8 pm Monday 15 Dec 2025 JSTForecast update in hr min s Forecast update imminent
Amatu surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Amatu sea temperature is
19.6° C
(Which is normal for this time of year)How big are the waves at Amatu today?
The current surf forecast for Amatu at 3AM is: 0.6m 8s primary swell from a Southeast direction and 0.5m 8s secondary swell from a Southwest direction (forecast issued at 08:00pm December 15). An open ocean swell of 0.5m 3s is not directed at the surf break. The wind direction is predicted to be cross-offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (16 Dec) | 1.5ft (0.4m) | 12s |
| Afternoon (16 Dec) | 1.5ft (0.4m) | 12s |
| Evening (16 Dec) | 1.5ft (0.4m) | 12s |
Table - waves today at Amatu. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Mon 15 | Tuesday 16 | Wednesday 17 | Thursday 18 | |||||||||||||||||||||
| 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |   |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 9 | 9 | 8 | 8 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 7 | 12 | 12 | 11 | 7 | 7 | 7 | 6 | 18 | 17 | 16 | 16 | 7 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 93 | 59 | 57 | 44 | 44 | 52 | 37 | 37 | 60 | 61 | 58 | 56 | 56 | 55 | 50 | 52 | 168 | 85 | 46 | 30 | 55 | 102 | 100 | 116 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- off | cross- off | cross- off | cross- off | off | cross- off | off | glass | cross- off | glass | off | cross- off | glass | cross- off | glass | cross- off | cross- off | cross- off | off | off | cross- off | cross- off | cross- off | cross- off |
High Tide / height (m) | 3:09AM 1.15 | 1:32PM 1.32 | 4:00AM 1.22 | 2:08PM 1.34 | 4:43AM 1.28 | 2:43PM 1.35 | ||||||||||||||||||
Low Tide / height (m) | 8:13PM 0.43 | 7:47AM 0.91 | 8:51PM 0.30 | 8:44AM 0.94 | 9:27PM 0.19 | 9:33AM 0.95 | ||||||||||||||||||
Mon 15 | Tuesday 16 | Wednesday 17 | Thursday 18 | |||||||||||||||||||||
| Sunrise | - | - | - | - | - | 6:39 | - | - | - | - | - | - | - | 6:39 | - | - | - | - | - | - | - | 6:41 | - | - |
| Sunset | - | - | - | - | - | - | - | 4:28 | - | - | - | - | - | - | - | 4:28 | - | - | - | - | - | - | - | 4:29 |
 |  | |  | |  | | | | | | | |  | | | | | | | |  | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 10 | 9 | 9 | 9 | 8 | 8 | 10 | 10 | 10 | 10 | 10 | 9 | 9 | 10 | 12 | 13 | 11 | 11 | 10 | 9 | 10 | 10 | 11 | 11 |
| Feels °C (?) | 5 | 3 | 4 | 3 | 2 | 3 | 6 | 7 | 7 | 8 | 7 | 6 | 7 | 7 | 11 | 10 | 8 | 8 | 6 | 6 | 6 | 5 | 5 | 5 |
- 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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