If you are running the Platinum Ed. of WOFF, I recommend uninstalling the old ver. of the BuckeyeBob cloud/weather modification patch (ver. 2.9.2) - and installing instead ver. 3.0 which is Plat. Ed.-friendly. (see this post for a link to ver. 3.0:
https://SimHQ.com/forum/ubbthreads.php/topics/4334403/optional-cloud-mod). Also, in ver. 3.0, there is a "lighter weather" option if I remember correctly - that, if cloud popping/flickering still occurs, is the recommended install route since the lighter weather package contains less fog (low-lying fog sometimes increases fog, and cloud, popping and flickering). You might also want to remove the ver. 1.2 patch of my WOFF GPU Tuner (since you have 1.1.1, 1.3, 1.4 installed) - although the tuner patch is not related to cloud popping.
Von S