A numerical study of a southeast Australian coastal ridging event disturbance

C.J.C. Reason
P.L. Jackson

submitted to Meteorological Applications, March 2001


An important component of southeastern Australian weather during the summer half of the year is coastal ridging. The mesoscale aspects of these events are often not well forecast and this has adverse implications for aviation, shipping, air quality and bushfire danger for example. A previous study by Speer and Leslie has classified coastal ridging into three types depending on the associated synoptic conditions. In this study, a coastal ridging event that appears to have aspects of all three types is examined with the aid of mesoscale manual analyses, surface and radiosonde data and simulations with a mesoscale numerical model (Colorado State University Regional Atmospheric Modeling System).

It is found that the model is able to capture the salient features of the event but tends to be a little weaker on the east coast than observed. The model ridging also tends to lag the observed feature on the east coast by a few hours. It is suggested that these model deficiencies may relate to those in lower atmosphere air mass characteristics which, in turn, may relate to the surface parameterizations in the model.