There are two "Maximum number of icons to display" dropdowns. One is for the daily forecast, and the other is for the hourly forecast. Currently, your extension is setup to show the current condition icon and one daily forecast icon. Setting both dropdowns to "0" will remove all but the current conditions icon.
The only way to see the hourly forecast is to display one or more hourly forecast icons. Clicking any of the icons in the extension will link you back to WeatherBug.com for more details.
Have you tried the Weather Watcher Live Windows application? You can view the entire hourly forecast without linking back to WeatherBug.com. If you haven't seen it, then check out the virtual demo at http://www.SingersCreations.com