No, Its not something dirty. A Habob is a massive dust storm. One hit Phoenix last week. This one was somewhere between 3 and 5 thousand feet high. Ka-razy.
I should have gone outside to check it out. I just heard the crazy wind, looked up from my book, and said "sounds windy" to my new roommate Wendy. She looked up from her book and said, "yup" and then we both went back to reading. We're an exciting bunch.
I had no idea what was happening, but this is what I saw when I went outside the next morning...
And here's a side view:
There is still dust blowing all over the place several days later. Such exciting weather!