High Temperature Extremes in Australia∗

ABSTRACT Magnitude-frequency analysis by the Gumbel method of temperature records at 166 Australian stations produced data for maps of extreme temperatures at recurrence intervals of 1.58, 2.33, five, ten, twenty-five, fifty, and 100 years on the annual series, plus a generalized map of actual values for the 100-year interval. Whereas the extremes for recurrence intervals up to about twenty-five years conform well to the Theory of Extreme Values, those for greater recurrence intervals produce convex-upward graphs, suggesting a similarity to Gumbel's Type III probability. In some parts of the continent ranges between the 1.58-year and the 100-year extremes are small. Graphs for some very exposed coastal stations flatten abruptly in their upper ranges. Sample occurrences of absolute extremes at selected stations involved unusual transport of cTW air from the interior at low levels across the coastlands in association with patterns of cyclonicity and anticyclonicity that for the most part contrast with most frequent patterns.