Doppler radar for weather forecast
(http://img.nauticexpo.com/images_ne/photo-g/boat-aluminium-radar-mount-175345.jpg)
This idea goes like this. Mars Colony has a small Doppler radar on the roof. This radar creates a doppler-map of the surrounding terrain (up to few houndrets kilometers away). This map shows where it's calm and where it's not. This map changes slowly and randomly (some storms are born and other fade), and moves in the wind dirrection (which is also random, but changes slowly).
If the storm (the BIG RED DOT) cross-over the map area, there will be storm.
Storms are surrounded by dust-fog areas (Multiple Yellow dots), and if you'r base isn't hit by the storm area, it will most likely be hit by a fog-storm.
Other types of weather phenomena has other colours (like: Cold-Storm or Global Dust-storm).
The intensity of the dot colour tells us how strong the phenomena is.
The dot size and wind speed tells us how fast the storm will pass-by.
(http://img823.imageshack.us/img823/4546/weather1g.png)
So the weather is random, but you can forecast it to a some degree ahead. Player can simply come to the doppler-radar console and see the doppler map. If he see's that a big red dot is comming streight at the base, he will alert other marsonauts to get to a shelter.
If he thinks that the storm will not hit the base dirrectly and only pass-by (fog-storm) he will tell other players to not be alarmed.
And becouse the map changes slowly in a random pattern, he will never have a 100% forecast efficiency.