To: BOM Synoptic Discussion Group <synoptic_discussion@BoM.GOV.AU>
Subject: [synoptic_discussion] YMML "cool change"

Gang:

I am curious regarding the character of this morning's cool change in Melbourne.  The question is not quite as VIC-centric as it might sound, as I propose that we are seeing the interaction of a cool change with weak synoptic support with diurnally driven coastline-modulated sea breeze effects.

I am seeing a ~3 C temp. drop around 11am in Melbourne, with a subsequent climb to  27.6 C by 3pm.  A surface station plot around 3pm reveals cool (15-17 C)  westerlies in SW VIC, but warm (25+ C) westerlies in the Bay Area. Gippsland (Morwell) shows SW flow with T ~ 20+ C, so it looks like the change has moved through at that location.

Forecasters,  what will that change look like once the sun goes down? Will Melbourne "run out of" warm air over the next 1-2 h and start tapping cooler air with maritime parcels?  If so, what would you call such a temperature change?

Adding to the confusion, Harald