We are all dependent on the weather, and knowing what Mother Nature has in store for us in the next 24hrs helps our daily routine. Backyard astronomers don’t have the luxury to be setup on top of a mountain range, above the clouds where the air is crisp and dry all the time. Therefore knowing in advance if it’s worth hauling out all your gear for a six-hour deep-sky photo-session or a minimalist setup to scan the planets and the Moon can save lots of frustration.
One of the great tools out there is Clear Sky Chart.
Using data and forecasting models from Environment Canada specifically tailored for astronomers the site provides a simple chart with past, current and forecasted conditions of various parameters that affect the viewing quality. In the above snap-shot cloud cover, transparency and humidity all indicate bad viewing conditions for Friday and Saturday night. (Boooo…..)
While the data is from Environment Canada, Clear Sky Chart provides coverage for the USA and part of Mexico. On the web site you can select the closest observation site, or request to create your own. If your setup is mobile, you can check the viewing conditions at various locations to see if it’s worth to pack up your gear for a road-trip to a place with less light pollution and better weather.
An Android app is also available for your mobile devices and tablets: Clear Sky Droid, essentially using the same charts and data set.
As the saying goes: Clear and dark skies!