These cool changes associated with easterly dips, as we had this morning, are very complex and difficult to understand.  Last night in Melbourne, we had a fantastic thunderstorm, with strong winds, heavy rain pelting down, large drops... it all had a very tropical feel to it... Yet  as far as I can tell, the major change/frontal passage  was this morning (say around 2200 UTC).  I grabbed the 24-hour maptool loop from the VIC RFC web-browser and have put it on my web page.

Looking at the winds-temps around the time of the thunderstorm (say 0900 25 Feb), there seems to be something like a far-inland protrusion of the sea-breeze coming up against the northerly component of the easterly  dip, bringing about  convergence over Melbourne between westerlies and moist northerlies.  The language is loose and un-scientific, basically because I don't understand this process at all.... However, we did have something similar happen a couple of weeks ago, just before I went on holidays (see web-page discussion for the cool change on 4 February)
 

Do any of the forecasters that followed this change in detail (or the mesoscale expert G-M) have anything to say on the processes involved in these changes whereby the southerly flow comes in to replace an easterly dip?

cheers

John McB