The Bureau of Meteorology (BoM) marine forecast title of ‘strong wind warning’ understated the ‘damaging winds’ expected during the ‘severe thunderstorm’. The forecast did not use recognised marine weather terms for wind speed, such as ‘gale force’.
The undertaking by BoM to use standard terminology in marine weather forecasts should prevent a forecast being misunderstood. The formal consultative forums will also help in this regard while continuing to improve BoM’s product delivery, and meeting the needs of the end users of its forecasts and warnings.
The Bureau of Meteorology (BoM) advised the ATSB that the marine forecast title of ‘strong wind warning’ describes the average wind speeds in accordance with accepted service conventions. These conventions do not allow for the wind gust speeds expected during thunderstorms to be included in the warning title. Where relevant, information on stronger wind gusts associated with thunderstorms is provided in the body of the forecast.
However, BoM recognised that the use of the term ‘damaging’ within the body of a marine forecast was unusual. Although the intent was to provide additional intelligence, BoM advised that it has undertaken to use standard terminology within its marine forecasts.
Other BoM safety action includes a formal process to conduct regular consultative meetings and workshops with key marine stakeholders to identify current and future requirements. Fremantle Port’s harbour master is invited to attend these forums, where BoM undertakes to continue to raise relevant issues.
In its response, BoM also advised that users should familiarise themselves with all relevant warning products, understand the basis on which these are issued and the range of terminology used. The BoM website provides information that explains the marine forecast service refers to the use of ‘severe thunderstorm’ warnings in capital city local waters forecast, which include Fremantle. Therefore, when thunderstorms are forecast for capital city local waters, it is important to check if a ‘severe thunderstorm’ warning has been issued for the capital city (issued when wind gusts exceeding 48 knots, or large hail or heavy rainfall is expected).