Just try going some place away from any Gates, and entering 'set ANWeatherQuest.Oblivion to 0' into the console, and see what happens. That should force AN to stop treating it as near a Gate, and so if you wait 24 hours, the weather should have changed to something normal. Then see if the bug happens again after that.
'Fraid so. Went to Kvatch, entered the command, waited 24 hours, Kvatch was still in the grip of a downpour and approaching the city proper still instantly triggered a gatestorm accompanied by rain. Entered a tent in the Kvatch camp and waited 72 hours to reset cells and make completely sure, but with the same results. Reloaded my save, traveled to Anvil, re-entered the command and waited 24 hours. Traveled to Kvatch to receive the same results.
A new wrinkle, however...when waiting outside Anvil, at the end of the 24-hour period I was receiving the sound effects of what appeared to be a heavy downpour, despite only slightly cloudy skies. Unless this is a "heavy wind" weather I've just never run into before or something (and frankly, I kinda doubt that), it seems that whatever bug(s) I'm experiencing with AN aren't quite limited to gatestorms. Were there possibly some misassigned sound effects in 9.9.5 that the fix pack was to have corrected or anything?
(I ask because it seems more and more likely to me that the game just isn't registering the fix pack corrections for some reason, so if I've just run into another bug that was corrected in the fix pack that might give me a bit more grounding for my thoughts.)
EDIT: I just realized that I probably should have tried testing the above fix on one of the random gates rather than the Kvatch one, since that probably has its own quest-related scripty things going on. I'll look into that, see if there are any differences...if it doesn't change anything, I guess I'll cobble together the closest facsimile of the AN Natural Interiors that I can (that being the part of this mod that I find completely indispensable for my experience) and just use Enhanced Weather for the time being. Not at all my first choice, and I still vehemently hope there's a way to fix this, but the likelihood of that is looking slimmer and slimmer :/
That said, If ANYONE out there has any idea how to fix this, please do let me know.
EDIT EDIT: Progressed one of my test saves past the Save The Heir quest, thereby activating random gates. The Kvatch gate did what is has done for me all along, but to its credit the gatestorm did NOT persist after closing the gate. However, having run across several random gates now, I can confirm that they exhibit the gatestorm and rain of the Kvatch gate, and furthermore that they DO persist after closing the gate in question. Dammit.
EDIT EDIT EDIT (Because I just won't shut up already): This is to the mod authors directly, or at least the two who I've "talked" to--you two have been infinitely helpful and patient with me already...if there's nothing more you can think of, I'm cool with that. I'm going to miss the prettiness of AN, and I'm going to
desperately miss the jawdropping immersion factor of Natural Interiors, but I guess there's only so much that can be done. Thanks to both of you, and even if I can't figure out why it hates me, this is one hell of a mod.