Clear Sky Chart
Cellphone Version
For WAP 1.0 (*)

What is it?

If you have a web-enabled cellphone, you can read a text-version of the Carr Astronomical Observatory clear sky chart. Because of the limitations of cellphone displays, the cellphone chart is simplified. However, it still displays hourly cloud-cover, transparency and seeing forecasts.

How do I see the Carr Astronomical Observatory cellphone chart?

Enter this url into your cellphone's browser:

The url is case sensitive.

(Actually, it's excruciatingly tedious to type urls into cellphones. Check to see if your cell service provider provides a web page that will allow you to download bookmarks into your phone.)

Why don't all charts have cellphone versions?

Because of the extra cost of generating and hosting cellphone versions, they are only available for sponsored charts.
This one is thanks to

RASC Toronto Centre

How Do I read it?

Unfortuneately WAP 1.0 cell phones do not support color graphics or horizontal scrolling. So a normal chart display is out. Instead, a cellphone chart is a vertical list of text. Each row is for a particular hour. The columns are the cloud-cover forecast, transparency forecast and seeing forecast. The forecasts have been reduced to a 1 to 5 numeric scale with the meanings:
1 to 5
0-Too Cloudy
to forecast
Too Cloudy
to forecast.
190% to overcastPoorBad (1/5)
260% to 80%Below AveragePoor (2/5)
350%AverageAverage (3/5)
420% to 30%Above AverageGood (4/5)
5ClearTransparentExcellent (5/5)

A display of 0 for transparency or seeing means those forecasts were not computed because it was too cloudy. In practice, when the forecast display is 0, conditions are terrible to unusable, rather than unknown. The transparency forecast is not computed, and displayed as 0, when cloudy cover is over 30%. The seeing forecast is not computed, and displayed as 0, when the cloud cover is over 80%.

(*) Why WAP 1.0.

WAP 1.0 is the standard for the microbrowser that most of us have in our cellphones. If you're one of the lucky few to have a WAP 2.0 cellphone with a wide display, you may be able to dispense with the text chart entirely and instead use the graphical icon version:

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