Shipping Forecasts
Wind Speed
Wind speed to described in terms of the Beaufort Scale
| Force |
Knots |
Wind |
Probable
sea state |
| 1 |
1-3 |
Light airs |
Ripples |
| 2 |
4-6 |
Light breeze |
Small wavelets |
| 3 |
7-10 |
Gentle breeze |
Crests begin to break |
| 4 |
11-16 |
Moderate breeze |
Waves becoming larger, frequent white horses |
| 5 |
17-21 |
Fresh breeze |
Moderate waves, many white horses, some spray |
| 6 |
22-27 |
Strong breeze |
Large waves, extensive white horses |
| 7 |
28-33 |
Near gale |
Sea heaps up, waves breaking, white foam blown
in streaks |
| 8 |
34-40 |
Gale |
Moderate high waves, crests break into spindrift,
white foam |
| 9 |
41-47 |
Strong gale |
High waves, crests topple spray affects visibility |
| 10 |
48-55 |
Storm |
Very high breaking waves, dense foam streaks |
This scale is only a rough guide and reflects average speeds, gusts
up to the next force should be anticipated. Sea conditions are generally
more severe nearer to land.
Timing
If a warning is described as Imminent it will arrive within 6 hours
of time of issue.
If a warning is described as Soon it will arrive in 6-12 hours.
If a warning is described as Later if will arrive in 12+ hours.
Visibility
This relates to how far it is possible to see:
If visibility is Good visibility is more than 5 miles
If visibility is Moderate visibility is 2-5 miles
If visibility is Poor visibility is1000m - 2 Miles
If visibility is Fog visibility is less than 1000m
Speeds of Weather Systems
This is how fast the whole weather system is moving
Slowly = 0-15 Knot
Steadily = 15-25 Knots
Rather quickly = 23-35 Knots
Rapidly = 35-45 Knots
Very Rapidly 45+ Knots
Sea Areas
The Shipping Forecast is divided into sea areas. This is a map of
the areas close to shore, together with (some of) the coastal stations
.
T = Tiree
BL = Butt of Lewis
Su = Sumburgh
B = Bell Rock
D = Dowsing
V = Varne
RS = Royal Sovereign
C = Channel
S = Scilly
Va = Valentia
R = Ronaldsway
M = Malin Head
J = Jersey
