| Stable air at mountain top altitude and a wind at least 20 knots blowing across the mountain ridge |
| Moist unstable air at mountain top and wind of less than 5 knots blowing across the mountain ridge |
| Either stable or unstable air at mountain top and a wind of at least 30 knots blowing parallel to the mountain ridge |
| Unstable air at mountain top altitude and a wind at least 20 knots blowing across the mountain ridge |
EN 