Phil's blog

Cloud Forecast Accuracy

This set of images compares the actual infrared satellite image for midday Saturday 13th September 2008 with forecasts made on the same day and up to 5 days ahead. The forecasts made up to 2-3 days ahead are quite accurate, so that a reasonable estimate of the astronomy prospects for a Saturday night could be made on the Thursday beforehand. While the general trends are still correct in the 5 day forecast, the details for a particular location become much less accurate.

Cloud Forecasts for Victoria, Australia

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.

Check out Cloud Forecasts for Astronomers for the story behind some of this and how to generate your own cloud forecast maps using US GFS model data.

Also see Cloud Forecast Accuracy for comparisons of the forecast charts with actual satellite images.

Melbourne




Explanation Key:



Cloud Forecasts for Astronomers

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:

Peak Oil on ABC Stateline in Victoria




Originally published on The Oil Drum.

How Technology Increases Oil Production

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.



The Oil Drum



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

Astrophotography Test: Canon 20D/40D - ISO Setting - Sub-Exposure Length

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.

The Big Dipper - Ursa Major Rising

Click the heading for the full story..

2007 According to Kaz (and Phil)

And so it’s time for an update for 2007..

Total Lunar Eclipse: Tuesday 28th August 2007

The full gallery of lunar eclipse photos is here:
http://philhart.com/gallery/Astrophotography/Moon/Lunar_Eclipse_2007/

A lot of Planning and Preparation

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