Weather guide
Reading a marine forecast
The models give the detail; the official forecast gives human expertise and the strong-wind warnings. The two are complementary.
The structure of a coastal forecast
A marine forecast (inshore, offshore) always follows the same order:
- Warnings in force (special weather bulletins): near gale, gale, storm…
- General situation: position of lows and highs.
- Forecast by area: wind (direction + Beaufort force), sea, weather, visibility.
- Later trend.
The warning thresholds to know
| Warning | Force (Beaufort) | Mean wind |
|---|---|---|
| Near gale warning | 7 | 28–33 knots |
| Gale warning | 8 | 34–40 knots |
| Severe gale warning | 9 | 41–47 knots |
| Storm warning | 10–11 | 48–63 knots |
| Hurricane-force warning | 12 | ≥ 64 knots |
Reminder: these forces are mean winds. Gusts are appreciably higher.
Rule of thumb: a stated warning must take priority over a more optimistic model. When in doubt between the forecast and the app, go with the more cautious one.
Example
Forecast: "Gale warning, northwest 7 to 8 freshening 9 in the evening, sea rough to very rough". Translation: 30–40 knots rising towards 45, sea 2.5–4 m. Postpone the outing.
Cross-checking with the models
The forecast says "what" and "how much", the models say "exactly where" and "at what time". Use the app to see the hour-by-hour evolution and spot the lulls, but let the official warning set your level of caution.