Air mass and dynamic parameters affecting trade wind precipitation on the northeast Queensland tropical coast

Daily precipitation data for 21 rainfall reporting stations along the northeast Queensland tropical coast were collated for a period of 168 days during periods of sustained trade wind flow. Parameters that may influence precipitation were classified as either characteristic of the prevailing air mass or dynamic in nature. Parameters that displayed a high correlation with daily precipitation were derived by combining air mass and dynamic parameters. Dynamic parameters displayed stronger relationships with trade flow rainfall than upstream air mass indicators, with synoptic scale coastal forcing predominating. Derived parameters involving a combination of air mass and dynamic parameters provided the best individual indicators of daily precipitation with a linear correlation of up to 0.74 and 0.70 for regionalized and individual station daily rainfall, respectively. Linear regression techniques are used to develop five-parameter multivariate equations sourced from 1525 potential parameters. For the developmental data, the resulting equations account for 65 and up to 58% of the variance of regionalized and individual station daily rainfall, respectively. A 53 day trial test, using these equations on independent data produced a linear correlation of 0.83 and 0.68 for regionalized and individual station daily rainfall, respectively. © 1998 Royal Meteorological Society