I used to really like WeatherBug, but it hogged up valuable resources in order to run. I then found this little FireFox extension that gives me real-time weather and alerts at almost no cost to system resources. Forecastfox sits to the right of the search bar in the browser and is hardly noticeable when you’re trying to do other things. There really isn’t much else to say about this program other than it does a great job of getting to the point and giving you only the information you need. Give it a try and I’m sure you’ll be satisfied!

Link: http://forecastfox.mozdev.org