Phil's blog

Edit Oct 2009: Since I originally wrote this article, SkippySky has become available. It uses the same US GFS weather model data so the discussion about accuracy is still relevant, but SkippySky is a much more convenient way to access the cloud forecast data, with great maps for all of Australia among other places.

Astronomers want good weather forecasts. In particular, they need to know about cloud. When you're deciding whether to travel two hours to a dark sky site for the weekend, an accurate forecast is invaluable.

Saturday 13th September 2008

1 Day Ahead Forecast

The 'Clear Sky Clock' is available via the web to amateur astronomers across North America, and includes not only cloud forecasts but also estimates for transparency and seeing. For those of us in the rest of the world, there are several other options:

• Updated Oct 2009: SkippySky - The most convenient option now for Australia, New Zealand and Europe.
• Global Forecast System (GFS) Cloud Charts from US NCEP
• 7Timer Astroweather Panel (APanel) Forecasts by Quanzhi
• Astroforecast.org Cloud Forecasts by Jeff Bullard
• Air Force MM5 Model Cloud Top Temperature Charts

How can you double something and still have ten times less than you started with?

The answer to this question will help us reassess claims that advances in oil field technology will postpone the peak in global oil production. The question itself arises from a case study of Enhanced Oil Recovery in the Handil Oil Field in Indonesia.

Observant fans may have noticed a lack of new stories here recently (although new astrophotos are being added to the Gallery).

Having 'upgraded' to a Hutech modified Canon 40D Digital SLR, I was keen to see how it compared to my existing Hutech 20D and what the optimum settings were for ISO and sub-exposure length. The images and results here for the 20D and 40D should be comparable with a 350D and 450D respectively since they use the same sensor.