sorry for the large link, i just read about dust storms in alberta during the 30's, and i thought the looming branching effect of the sand and dust was exactly what an approaching ash storm would look like. instead of appearing magically in a point in the air, why not have it roll in slowly from the direction of red mountain. you could see it coming, and it would be a magnificent sight.
Red hint that Lukkar suggested, and coming down from the Red Mountain should be saved for the Blightstorm. Ashstorm and blightstorm are two different things - first one is a natural weather phenomenon, really high speed winds blowing up volcanic dust from the ground. Blightstorm on the other hand is not natural, it is only weather-like, but it's a burst of Dagoth Ur's magic, using the power of Lorkhan's heart, and the smokes of Red Mountain. That one was red in Morrowind and so it should be in Skywind, also it should be the more hellish, with many lightning strikes and so on. It also carries blight diseases similar to corprus, and nightmares. You should be able to hear ominous whispers inside it, as it draws the habitants of Vvardenfell, animals and humanoids alike insane. So, Ashstorm should probably be, if anything, downplayed in comparison to it.
I'll be the first to admit that I'm not an ashstorm-ologist, but I noticed that the lightning tended to be very horizontal. Perhaps there could be some additional vertical lightning as well? That being said, things are looking top notch!
Fussy bunch of bastards. Any other qualified Meteorologists out there? The short answer is that if you want fancy lightning you'll need to offer to help for about two hours. Lots of tweaking numbers. Lets see how many people have an opinion now?
I have an opinion: this storm is freakin' awesome! Wonderful work guys ;)
Lightning is optional.
You have nice storm. It just would be better with more fuzz edge and small parts of it (clouds, dust walls, maybe tornadoes, semi-transparent overlayers) moving separately.
Then it will/would be perfect.
I had no idea it would be difficult to fix the lightning :( I retract what I said earlier, and now believe that the storm needs MOAR sideways lightning!