There are special 3D models of the solar wind that try to model the CME and its speed (it can slow down if it runs into a slower blob of solar wind). We have an upstream monitor at ACE, which gives us about 45 minutes warning of a CME hitting. We can use that data to predict solar storms, like the one last weekend.
We would love to have a solar monitor upstream that would give us 4 hours of warning... maybe using a solar sail!
Here is our space weather forecast page:
http://mms.rice.edu/realtime/forecast.html
You can send us email to get onto our space storm warning email list:
spacalrt-subscribe@mailman.rice.edu
..Doctor Pat