Strong wind
A wind force between 6 and 7 Beaufort is usually referred to as strong wind in Western and Central Europe . This is called "stormy" or storm .
Below are the usual limit values for some wind strengths.
| Wind force | m / s | km / h | node | Swell |
|---|---|---|---|---|
| 4 moderate breezes | 5,5 7,9 | 20-28 | 11-15 | (moderate breeze) |
| 5 fresh | 8.0-10.7 | 29-38 | 16-21 | moderately agitated sea |
| 6 strong | 10.8-13.8 | 39-49 | 22-27 | rough sea |
| 7 stiff | 13.9-17.1 | 50-61 | 28-33 | pretty rough sea |
| 8 stormy | 17.2-20.7 | 62-74 | 34-40 | high seas |
| 9 storm | 20.8-24.4 | 75-88 | 41-47 | |
| 10 severe storm | 24.5-28.4 | 89-102 | 48-55 | very high seas |
(10 = English storm ( French tempête ), whereas 9 = strong gale )
If “strong winds” (mostly 6–7 Bft., Ie 39–61 km / h) or storms (from 8 Bft. Or 62 km / h) are likely to occur, storm warnings are broadcast by radio or warned by optical signals .
The strong wind and storm warnings are issued as part of the regular weather report from the responsible weather services or coastal radio stations .