Hi Dave,
Nice catch! Spoke to Nick last night and he also captured and described the same feature. Well put it this way, there were low bases yesterday and the shear based on inflow were such that it was deep inflow. Could you please indicate which direction we were looking? It looks as if it were outflow and inflow interaction. How long did the feature last?
Seeing that sea surface temperatures were modest and the upper levels were cold, that provided decent lapse rates for the coastal suburbs at least during the morning. Despite the dynamics, there was the potential of waterspouts yesterday.
Regards,
Jimmy Deguara