Sorry for the double post, I'll leave this here in case someone else is having the same problem:
Vvardenfell Plume in Skyrim
You can control the visibility of the Vvardenfell plume by using the following console command:
set WTT_SkyrimPlumeMaxDistance to X
X is the max distance in Skyrim units. Default value is 307,200.
To make the plume visible from as far away as possible, use a value of 10,000,000.
You can the following console command to turn off the plume entirely.
set WTT_SkyrimPlumeEnabled to X
If X is set to 1, the plume is enabled, if it is set to 0, the plume will be disabled. (Sometimes it takes a few moments for it to register.)
There's also an optional plugin that sets this to 0 and as such disables the plume.