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:
Mera surfForecast / Chiba / Japan
48hr Weather and Surf, issued 8 pm Saturday 13 Dec 2025 JSTForecast update in hr min s Forecast update imminent
Mera surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Mera sea temperature is
20.1° C
(Which is normal for this time of year)How big are the waves at Mera today?
The current surf forecast for Mera at 11PM is: 0.6m 11s primary swell from a East direction and 1.3m 5s secondary swell from a East-southeast direction (forecast issued at 08:00pm December 13). An open ocean swell of 1.1m 5s is not directed at the surf break. The wind direction is predicted to be offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (13 Dec) | - | - |
| Afternoon (13 Dec) | - | - |
| Evening (13 Dec) | 2ft (0.6m) | 12s |
Table - waves today at Mera. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Sat 13 | Sunday 14 | Monday 15 | Tuesday 16 | |||||||||||||||||||||
| 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) (?) | 12 | 12 | 11 | 6 | 7 | 7 | 9 | 10 | 11 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 9 | 8 | 8 | 8 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 134 | 95 | 89 | 116 | 195 | 229 | 1017 | 2700 | 1733 | 2045 | 2310 | 1660 | 1767 | 1259 | 450 | 293 | 241 | 154 | 100 | 51 | 46 | 45 | 35 | 34 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | off | off | off | cross- off | cross- off | cross- off | cross- off | cross- on | cross- on | cross- on | cross- on | cross- on | cross- off | cross- off | off | off | off | off | off | off | off | cross- off | cross | glass |
High Tide / height (m) | 12:18AM 0.99 | 11:54AM 1.26 | 1:56AM 1.05 | 12:34PM 1.30 | 3:03AM 1.14 | 1:14PM 1.33 | ||||||||||||||||||
Low Tide / height (m) | 6:18PM 0.67 | 5:21AM 0.76 | 7:18PM 0.52 | 6:29AM 0.86 | 8:04PM 0.38 | 7:33AM 0.92 | ||||||||||||||||||
Sat 13 | Sunday 14 | Monday 15 | Tuesday 16 | |||||||||||||||||||||
| Sunrise | - | - | - | - | - | 6:39 | - | - | - | - | - | - | - | 6:39 | - | - | - | - | - | - | - | 6:39 | - | - |
| Sunset | - | - | - | - | - | - | - | 4:30 | - | - | - | - | - | - | - | 4:30 | - | - | - | - | - | - | - | 4:30 |
 | | |  | |  |  |  |  | | | | |  | | | | |  |  | |  | | | |
Rain (mm) | 1 | 3 | 3 | 1 | 3 | 10 | 4 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 10 | 10 | 11 | 11 | 10 | 10 | 11 | 13 | 14 | 13 | 12 | 12 | 11 | 12 | 12 | 12 | 12 | 10 | 10 | 9 | 9 | 9 | 10 | 11 |
| Feels °C (?) | 4 | 6 | 8 | 7 | 6 | 5 | 6 | 9 | 2 | 3 | 0 | 3 | 5 | 7 | 8 | 7 | 6 | 3 | 3 | 2 | 2 | 3 | 6 | 9 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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