We interpolated the WRF-CAMx winds to the time of the GCAS overpass. We used second-order differences and performed the flux divergences along the x/y axes (i.e., using the cells to the north, south, east, and west of the central cell). We also calculated the flux divergence for the cross-terms (i.e., using the cells to the north-east, south-east, south-west and north-west of the central cell). Averaging both the x/y estimate and the cross-estimate led to smoother divergence fields with less noise.