In early season (July) during some winters a good covering of snow falls in the Queenstown basin. In order to get snow to such low levels a southerly front from deep in the southern ocean must sweep up the country. Southland will be the first to get hit with snow, falling to sea level, followed by the Eyre Mountains, Garvies, Hector Mountains and eventually the Queenstown Basin. This is a perfect storm for Coronet peak which can pick up half a metre of snow in such an event.
After the snow fall, if the winds swing back around to the west or north the snow will quickly melt. However if there are several cold fronts in a row and the winds stay from the south, then Ben Lomond can be ‘on’.
For access there is the option of the Gondola, however in order to get up Ben Lomond early enough most people start the walk from Brecon St .For further access check out
http://www.doc.govt.nz/parks-and-recreation/places-to-go/otago/places/queenstown-area/things-to-do/ben-lomond-track/
The terrain is complex so the correct line must be scouted out beforehand to avoid getting bluffed. Here is a couple of clips of a few lad’s adventures, steep backcountry skiing Queenstown.