Marine weather forecasting

In view of the importance of the oceans and the vulnerability of people at sea to wind and wave, it is not surprising that the provision of marine weather services is an ongoing preoccupation of the World Meteorological Organization (WMO) and one of the most important functions of the national Meteorological Services of coastal and maritime nations. The earliest formal meteorological services were those for mariners, the first international conference on marine meteorology being held in Brussels in 1853 where a uniform approach to taking meteorological observations on board ships was established. Shortly after the Brussels conference, national Meteorological Services were established in a number of countries to provide weather warnings and forecasts for coastal areas. Only two decades later, in 1873, it was widely accepted that a permanent body was needed to promote the further development and application of meteorology through international cooperation and standardization and the concept of an International Meteorological Organization (IMO) was born. IMO effectively served the cause of international meteorology until the formal establishment of WMO on 23 March 1950. Marine meteorology is coordinated by the Joint WMO/IOC Commission for Oceanography and Marine Meteorology (JCOMM). (Image by courtesy of C&G plc)

The first weather maps based on telegraphic data were publicly displayed in Washington in 1850 and in 1905 radio-telegraph was used to relay weather reports from ships at sea to coastal radio stations. Subsequently, the First International Convention for the Safety of Life at Sea (the SOLAS Convention) called for coverage of all shipping lanes and fishing grounds with weather forecasts broadcast by radio. This led to the evolution of an international system for the collection of meteorological observations from the oceans, the analysis of these observations and the subsequent preparation and broadcast of meteorological bulletins to shipping. Over the years, WMO, its predecessor the IMO, and maritime organizations developed a coordinated system of marine forecast and warning services covering both coastal waters and the high seas.

With the international adoption in 1988 of the Global Maritime Distress and Safety System (GMDSS), marine communications have been updated to reflect advances in satellite and other communications technology and Morse-code qualified radio officers are fast disappearing from ships. Dissemination of meteorological warnings and forecasts to shipping is an integral part of the GMDSS system and GMDSS communications permit automatic shipboard receipt of weather and navigation information by INMARSAT satellite communications, radiotelephony and radio-telex (NAVTEX). Regularly scheduled weather, sea-state and ice forecasts along with warnings of tropical cyclones, gales, storms and other hazards are now routed to ships at sea by INMARSAT and NAVTEX broadcasts. In addition, these products are still broadcast by some coastal radio stations though this method is gradually being eliminated as the world's shipping approaches full compliance with the GMDSS communications system.

Increasingly forecast products are available via the Internet, although convenient web access is currently impossible for most ships at sea. As communications technology advances, however, it is likely that this problem will be resolved and Internet access by mariners to weather and wave forecasts will become commonplace.