Vertical Thunderstorm 18 Monday Aug 2014 Posted by Dagny Gromer in az monsoon ≈ Leave a comment Tagsaz monsoon, prescott az, thunderstorm This strange looking thunderstorm was over Prescott, Az on August 17, 2014. This was taken near the Prescott High School. At first the column was vertical, then it changed to this shape. It looks very much like the smoke column from a forest fire. Advertisement