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:
Shida surfForecast / Chiba / Japan
48hr Weather and Surf, issued 2 pm Wednesday 17 Dec 2025 JSTForecast update in hr min s Forecast update imminent
Shida surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Shida sea temperature is
17.9° C
(Which is 1.2°C colder than average for this time of year)How big are the waves at Shida today?
The current surf forecast for Shida at 7PM is: 0.4m 11s primary swell from a East-northeast direction and 0.4m 5s secondary swell from a Northeast direction (forecast issued at 02:00pm December 17). An open ocean swell of 1.2m 6s is not directed at the surf break. The wind direction is predicted to be cross-offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (17 Dec) | - | - |
| Afternoon (17 Dec) | 1.5ft (0.4m) | 11s |
| Evening (17 Dec) | 4.5ft (1.4m) | 6s |
Table - waves today at Shida. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Wednesday 17 | Thursday 18 | Friday 19 | Saturday 20 | |||||||||||||||||||||
| 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 | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 11 | 11 | 11 | 6 | 7 | 7 | 17 | 6 | 8 | 8 | 8 | 14 | 14 | 14 | 13 | 13 | 13 | 12 | 12 | 12 | 12 | 11 | 11 | 11 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 41 | 40 | 40 | 152 | 103 | 57 | 49 | 87 | 151 | 143 | 112 | 107 | 150 | 140 | 139 | 125 | 129 | 121 | 104 | 99 | 67 | 65 | 63 | 61 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | glass | cross- off | cross- off | cross- off | cross- on | on | on | cross- on | cross- on | cross- on | cross | cross | cross- on | cross- on | glass | on | glass | off | cross- off | off | off | off | off | off |
High Tide / height (m) | 4:12AM 1.30 | 2:00PM 1.39 | 4:48AM 1.34 | 2:37PM 1.42 | 5:22AM 1.36 | |||||||||||||||||||
Low Tide / height (m) | 8:51PM 0.21 | 8:51AM 1.02 | 9:27PM 0.14 | 9:31AM 1.03 | 10:03PM 0.09 | |||||||||||||||||||
Wednesday 17 | Thursday 18 | Friday 19 | Saturday 20 | |||||||||||||||||||||
| Sunrise | - | - | - | - | - | - | - | 6:41 | - | - | - | - | - | - | - | 6:41 | - | - | - | - | - | - | - | 6:41 |
| Sunset | - | 4:27 | - | - | - | - | - | - | - | 4:27 | - | - | - | - | - | - | - | 4:28 | - | - | - | - | - | - |
 |  |  |  | | | | |  | |  | | | | | | | | |  | | | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 1 | - | - | - | - |
| Temp. °C | 12 | 13 | 13 | 14 | 11 | 10 | 9 | 10 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 11 | 12 | 13 | 14 | 16 | 16 | 17 | 17 | 18 |
| Feels °C (?) | 10 | 9 | 8 | 8 | 6 | 5 | 3 | 5 | 7 | 6 | 6 | 6 | 7 | 8 | 9 | 8 | 10 | 11 | 12 | 12 | 11 | 12 | 11 | 12 |
- 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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