Snow cannons can only operate if the conditions are right. That is, temps must be no higher than -3ºc and no lower than -10ºc. Any higher and the spray will not form crystals and any lower they will just produce ice. People often think they just need to be turned on and they will produce snow, but this is not the case.
There are more cannons this year that ever before but certainly not enough to produce enough snow to open a resort on. They are there to top up thin areas only.