A climatology of Australian heat low events

Heat lows are a persistent feature over northern Australia between the Austral late spring and early autumn. The first ever multi-decadal climatology of individual Australian heat lows is presented here, based on an automated detection scheme applied to 35 years of ERA-Interim reanalysis data. Australian heat lows occur most frequently over the northwest of the continent and exhibit a pronounced seasonal cycle in both their frequency and intensity. Heat lows occur in response to surface heating and are most common over Australia during December and January when they can be detected on 95% of days. These months are also when the heat lows are most intense in terms of the central pressure and low-level cyclonic circulation. A composite heat low based on all heat low detections enables the three-dimensional structure of the heat lows to be analysed. The shallow nature of the heat low is clearly evident, and the structure is consistent with heat low observations in other regions of the globe. The similarity between the results presented here and the results of previous modelling studies as well as possible links between Australian heat lows and local weather is discussed. © 2016 Royal Meteorological Societ