>> On average, how often does the Flagstaff area experience >> sights of the aurora? In my 35 years here, it's a few times per solar cycle, usually within a couple of years of solar max. Not readily predictable, though one can pay attention to the various solar activity pages, such as: http://www.spacew.com/www/aurora.php ...where the top-most map and the bottom-most map are the most relevant. It's been my experience that (in re the bottom map) the "power output" has to be pushing 200GW for aurorae to be visible here. The green spot in middle of the map (today) will be relatively large and glowing bright red on such occasions. \Brian -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.