violated, namely that the clouds are much denser than the intercloud medium, the clouds are uniformly distributed in space and the filling factor of the clouds is small. We fulfill these criteria by randomly placing clouds that are a factor of 100 times denser than the intercloud medium with an overall small volume filling factor (dictated by the $C$ parameter, see below). We set off the SN explosion in this medium by putting the appropriate amount of thermal energy in a small number of parcels at the center of the remnant. We do not include any ejecta mass, which would be important at early times during the ejecta dominated phase. The characteristic time for the transition from the ejecta dominated to Sedov phase is [@Truelove+McKee_1999] $t_{ch} = E^{-1/2} M_\mathrm{ej} \rho^{-1/3}$, which for our values of explosion energy and density, and assuming 5 $M_\odot$ of ejecta, is about 2700 yr. It will take several times this value for the evolution to truly settle into a Sedov solution evolution in the remnant as a whole, though the approach will be faster for the region behind the forward shock. For this reason we do not expect the early time evolution (e.g. X-ray luminosity) 