A panel for a combustor of a gas turbine engine includes a cold side defining at least one convex portion and at least one concave portion. The concave portion is in communication with a passage. A method of operating a combustor section of a gas turbine engine includes: directing an impingement flow toward a multiple of peaks on a cold side of a panel; directing the impingement flow from the multiple of peaks toward a multiple of troughs with a multiple of entrances on the cold side of the panel; and directing the impingement flow through the multiple of entrances and a respective multiple of effusion passages through the panel.