Synoptic data from Renmark and Nuriootpa have been analysed by using multiple linear regression, supplementing earlier work on frost prediction for Nuriootpa (Veitch 1959). It has been shown that the regression coefficients associated with radiational heat loss are homogeneous between years and between stations, but those associated with wind effects are distinct between the two stations. The constant terms of the regression equations are heterogeneous between stations and between years. Using 1800 C.S.T. data, the percentage of variance of minimum temperature explained by regressions is 70 at Nuriootpa and 80 at Renmark. If mean cloud cover overnight is used for Renmark regressions, the variance explained by regression rises to 86 per cent providing direct evidence that errors associated with variable cloud cover fundamentally limit further progress.
LG Veitch (Tue,) studied this question.