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:
The Knap surfForecast / Wales – South East / UK
48hr Weather and Surf, issued 11 am Tuesday 16 Dec 2025 GMTForecast update in hr min s Forecast update imminent
Today's The Knap sea temperature is
9.5° C
(Which is 1.7°C colder than average for this time of year)How big are the waves at The Knap today?
The current surf forecast for The Knap at 1PM is: 0.4m 14s primary swell from a West-southwest direction and 0.2m 5s secondary swell from a West direction (forecast issued at 11:00am December 16). The wind direction is predicted to be cross-offshore.
| Time (GMT) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (16 Dec) | 1.5ft (0.4m) | 14s |
| Afternoon (16 Dec) | 1.5ft (0.4m) | 14s |
| Evening (16 Dec) | 1.5ft (0.4m) | 14s |
Table - waves today at The Knap. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Tuesday 16 | Wednesday 17 | Thursday 18 | Friday 19 | |||||||||||||||||||||
| 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 | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 9 | 10 | 11 | 11 | 12 | 21 | 20 | 20 | 19 | 19 | 18 | 18 | 17 | 17 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 69 | 69 | 67 | 66 | 65 | 63 | 63 | 63 | 60 | 34 | 56 | 78 | 89 | 186 | 104 | 148 | 412 | 407 | 365 | 358 | 546 | 413 | 505 | 493 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- off | cross- off | cross | cross- off | cross | cross- on | on | on | on | on | on | on | on | cross- on | cross | cross | cross- off | cross- on | on | cross- on | cross- on | cross- on | cross- on | cross- on |
High Tide / height (m) | 4:26PM 9.15 | 4:52AM 9.33 | 5:11PM 9.47 | 5:33AM 9.74 | 5:51PM 9.78 | |||||||||||||||||||
Low Tide / height (m) | 10:07AM 3.46 | 10:32PM 3.13 | 10:55AM 3.09 | 11:15PM 2.78 | 11:38AM 2.71 | 11:55PM 2.45 | ||||||||||||||||||
Tuesday 16 | Wednesday 17 | Thursday 18 | Friday 19 | |||||||||||||||||||||
| Sunrise | 8:11 | - | - | - | - | - | - | - | 8:11 | - | - | - | - | - | - | - | 8:12 | - | - | - | - | - | - | - |
| Sunset | - | - | 4:04 | - | - | - | - | - | - | - | 4:05 | - | - | - | - | - | - | - | 4:05 | - | - | - | - | - |
 | |  |  | | | |  | |  | |  | | | | | |  |  | | | | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | 1 | 4 | 4 | 3 | 3 | - | - | - | 8 | 11 | 3 | - | - | - | - |
| Temp. °C | 9 | 9 | 9 | 8 | 7 | 7 | 6 | 6 | 8 | 9 | 9 | 10 | 11 | 11 | 9 | 9 | 9 | 12 | 11 | 10 | 8 | 8 | 8 | 8 |
| Feels °C (?) | 7 | 6 | 6 | 5 | 4 | 5 | 2 | 1 | 2 | 2 | 1 | 1 | 3 | 8 | 7 | 6 | 6 | 4 | -1 | 0 | 0 | 0 | 0 | 1 |
- 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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