We are even getting tornadoes in northern California, a rare occurrence. Unfortunately, weather is not a part of my state standards, so I do not have many resources. I am pulling out my old JASON curriculum - Monster Storms, which does cover tornadoes and hurricanes.
What I have always liked about JASON is the connection to real scientists. This provides some new examples of careers as well as covering science content with hands-on activities. It has an online component. It is gated, but free.
NASA works with NOAA and many researchers to study these extreme weather events from space. The educational materials are a little dated; however, the data from new satellites and computer models is amazing when put into animations.
Here is a site that lists some of the small educational videos online: http://www.nasa.gov/audience/foreducators/topnav/materials/listbyty...
For hurricane animations and videos from the Goddard Science Visualizations Studios: http://svs.gsfc.nasa.gov/search/Keyword/Hurricane.html
For Tornado videos from SVS:
Hope these are helpful.