Forecasts

How to Read the Shipping Forecast — Every Term Decoded

Published · Last checked October 2026

The Shipping Forecast gives, for each of 31 sea areas around the British Isles, four items in a fixed order: wind direction and Beaufort force, sea state, weather and visibility. 'Southwest 5 to 7, occasionally gale 8 later. Moderate or rough. Rain. Good, occasionally poor' means a south-westerly force 5 to 7 with gales possible more than 12 hours ahead, waves 1.25 to 4 m, rain, and visibility over 5 miles dropping to 1000 m–2 miles at times.

Black and white photo of a dark sea under heavy clouds with sunlight breaking through
The kind of sky the Shipping Forecast prepares you for. Photo: Christopher Michel, CC BY 2.0.
The tall radio masts of the Droitwich transmitting station in a field
The Droitwich transmitter, which broadcasts BBC Radio 4 on long wave, carrying the Shipping Forecast far out to sea. Photo: Tom Axford 1, CC BY-SA 4.0.

The structure

  1. Gale warnings in force.
  2. General synopsis: where the highs and lows are, their pressure, and how they are moving, e.g. 'Low 985 moving steadily northeast, expected Rockall 978 by midnight'.
  3. Area forecasts: wind, sea state, weather, visibility for each area or group of areas, for the next 24 hours.
An example area forecast split into its four parts, wind, sea state, weather and visibility, each decoded, with the timing terms imminent, soon and later
One area forecast, decoded. The four parts always come in the same order.

Timing terms

Used in gale warnings and forecasts.
TermMeaning
ImminentWithin 6 hours of issue
Soon6 to 12 hours after issue
LaterMore than 12 hours after issue

Sea state and visibility

Official definitions.
Sea stateWave heightVisibilityRange
SmoothUnder 0.5 mGoodOver 5 miles
Slight0.5–1.25 mModerate2–5 miles
Moderate1.25–2.5 mPoor1000 m–2 miles
Rough2.5–4 mVery poorUnder 1000 m
Very rough4–6 m
High6–9 m

Wind words

  • Veering: changing clockwise (SW to W). Backing: anticlockwise (W to SW).
  • Cyclonic: big changes of direction as a low crosses the area.
  • Becoming: a change during the period. Occasionally: at times.
  • Systems moving slowly (under 15 kn), steadily (15–25), rather quickly (25–35), rapidly (35–45), very rapidly (over 45).

Paste any forecast into our Shipping Forecast decoder to see each term explained.

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Frequently asked questions

How many sea areas are there in the Shipping Forecast?

31, from Viking and the Utsires in the north-east round to Southeast Iceland.

What does 'later' mean in the Shipping Forecast?

More than 12 hours after the time the forecast was issued.

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