Australian Cloud Forecast for Astronomers.

[sydneystargazer]

Attached is the likely forecast map for 9pm tonight Monday 27th December for cities around Australia.

The picture gives only the most likely observing conditions for tonight as per data used by Sydneystargazers.

Our 24 hour forecast charts show the range of cloud you might expect to see around Australia. Two of the charts are added below.

For our forecasts, cloud coverage of less than 30% indicates clear sky while cloud coverage of 60% or more indicates overcast conditions are possible.

For example, if the chart indicates Melbourne will have cloud coverage of 5 to 28%, Melbourne will have good weather for the night. If however the cloud coverage was 69 - 99%, Melbourne can expect overcast conditions.

If there is cloud coverage for example of 15 - 52%, this indicates that there is cloud in proximity to the city so there is 50:50 forecast on clear sky or clouds developing..... depending on wind speed and direction.

A weekly forecast chart is also available.

The charts and maps are available at http://sydneystargazers.com/ for cities around Australia.

http://sydneystargazers.files.wordpress.co m/2010/12/australia-map25.jpg

http://sydneystargazers.files.wordpress.co m/2010/12/forecast25.jpg

http://sydneystargazers.files.wordpress.co m/2010/12/forecast-6-nights25.jpg

[sydneystargazer]

The best locations for observing tonight will be in the areas of :

Sydney
Canberra
Melbourne
Adelaide
Perth
Alice Springs

http://sydneystargazers.files.wordpress.co m/2010/12/australia-map28.jpg

[sydneystargazer]

The best locations for observing tonight will be in the areas of :

Melbourne
Adelaide


http://sydneystargazers.files.wordpress.co m/2011/01/australia-map1.jpg

[M54]

Thanks Roy. I've added this site to my favorites list.:thumbsup:

[Kevnool]

Lets see if i can do better than the cities tonight.

Cheers Kev.

[sydneystargazer]

Starting from yesterday, we now compare our forecasts around the country with actual visual observations of how much sky is obscured by cloud over each of the cities we forecast.

this will give us and you an idea how accurate our cloud forecast is and will prompt us to improve if neccesary.

at the moment 82% of our forecasts are correct.

http://sydneystargazers.files.wordpress.co m/2011/01/did-we-get-it-right1.jpg

[sydneystargazer]

The best places today for observing will be Adelaide and Alice Springs and even Cairns looks like it may see some sky tonight.

There is a remote chance that clouds expected for Melbourne tonight at 9pm may clear.

http://sydneystargazers.files.wordpress.co m/2011/01/australia-map4.jpg

[sydneystargazer]

After much deliberation, we have decided to revamp the way we do our forecasts.

We have thrown out all the figures and percentages... too messy and complicated..... and gone for a graphical representation of the likely weather for the night.

This will give us a better opportunity to tweak our forecasts and reflect changes to the weather pattern during the day.

We have also thrown out the 6 day forecast and replaced it with a 7 day forecast.

http://sydneystargazers.files.wordpress.co m/2011/01/tonights-forecast1.jpg

http://sydneystargazers.com

[sydneystargazer]

Looks like there will be a lot of cloud around Australia tonight. Best places for observing would be Perth and possibly Sydney .... though Sydney has a chance of cloud settling in tonight instead of the currently forecast clear skies at 7pm.

http://sydneystargazers.files.wordpress.co m/2011/01/tonights-forecast2.jpg

[sydneystargazer]

The best places for stargazing tonight look like Alice Springs and Perth.


Due to a number of email requests, we have brought back the original forecast system we had a week ago and have added that as a secondary forecast which shows a 24 hour forecast around Australia


Primary Forecast - night time only
http://sydneystargazers.files.wordpress.co m/2011/01/tonights-forecast8.jpg

Secondary Forecast - 24 hours
http://sydneystargazers.files.wordpress.co m/2011/01/forecast5.jpg

[RobF]

Thanks Roy. The 7day forecast alone is invaluable. Thanks for the great resource.

As an aside, the forecast for Brissy tonight was spot on (while both of my usual weather tools were not - either too pessimistic or optimistic)