Reference Point: Insert a spoke on each side of this hole.
It is not necessary to lace the radial spokes as shown above. Instead simply run the out-bound (a.k.a. heads-in) radial spokes along the outside of the crossed spokes.
If you are using Damon Rinard's Spoke Calc, then enter 3.25 for the cross number and 48 as the number of spokes.