Severe storms inferred from 150 years of subdaily pressure observations along Victoria’s “Shipwreck Coast”

Abstract

A severe storm index is created for Cape Otway using twice-daily in-situ surface pressure observations between 1865 and 2006. Events are identified from the 1st and 99th percentile of the probability distribution of pressure tendencies between subsequent sub-daily observations for each month. Each of the severe storms was then hand-checked against the original hand-written weather logs and other available historical archives. Of the 951 events identified over the period of study, 12 per cent were discovered to be due to keying errors in the data. Using the remaining quality-controlled data, the results show that the number of severe storms at Cape Otway has decreased significantly by about 40 per cent since the mid-19th century.