Using Numerical Convective Precipitation Product To Provide Gust Wind Warning

The sinking of the "Oriental Star" ship on June 1,2015,which shocked the whole world,resulted in the death of 442 people.The State Council concluded that it was a "particularly catastrophic event caused by severe storms and rains which caused by sudden and unusual strong convective weather".After that,serious maritime accidents caused by strong convective weather accompanied by strong gust wind occurred successively along the coast of China and Southeast Asia.It is difficult to monitor and predict severe convective weather and accompanied by gust wind because of its small horizontal scale,short duration and sudden occurrence.However,there is an urgent need for this in shipping industry.In recent years,the numerical prediction technology has made great progress and the products of numerical prediction have also been greatly enriched.It has become an important tool for forecasters to make weather forecasts and researchers to conduct scientific research.However,the ability of directly forecasting for similar small and medium scale weather systems and accompanied by gust wind is insufficient.In order to explore the weather forecasting factors that can provide early warning for gust wind in sub-grid in mesoscale numerical weather model products,three major maritime incidents of "Oriental Star" wreck,Qingdao bridge crane being blown down by Category 12 gale in June 2018 and Phuket wreck in July 2018 were analyzed from the aspects of heavy precipitation analysis,near-surface wind speed forecast,convection and continuous precipitation forecast.The results show that,according to the weather returns of the three events at that time,the wind speed forecast value of ECMWF forecast products is small,and the large scale precipitation has little relation with the gust wind,while the convective precipitation forecast value increases very strongly when the accident happens,which corresponds obviously to the gust wind accompanied by the strong convective weather in the middle and small scale at that time.The sharp increase trend of convective precipitation change 24 hours in advance is more obvious than 48 hours and 72 hours in advance,and the possibility of early warning of gust wind is greater.So,the change rate of CP in the numerical weather model prediction is a much potential factor for warning purpose.In the future if a system could be developed to more accurately forecast the gust wind based on this finding,then a better safety protection and early warning services would be expected for offshore and inland maritime navigation.