STORM2K

And don't know how to use HAS, this is a good site (scroll down to Case Studies, click on one of them and scroll down to Exercises, click on Event Data):

http://okfirst.ocs.ou.edu/train/training.html

It has the oh-so-hard to find data from the April 26, 1991 tornado outbreak (though only radar from TLX since the ICT and VNX WSR-88D's weren't installed yet apparently ), the Ft. Worth Hailstorm/Flash Flood from May 5, 1995, and the May 3, 1999 Oklahoma/Kansas tornado outbreak. It also contains soundings, upper-air and surface plots, and satellite images.

You will need the WxScope plug-in to view radar data - http://www.ocs.ou.edu/software/

Here's a sample if you're curious:



The arrow points to the supercell that is producing the Red Rock, OK tornado as of the time of the image (the one where researchers measured the highest wind speeds ever recorded in a tornado up until May 3, 1999, 287 mph). It is only rated an F4 despite that since it didn't hit any buildings. One of the several that occurred on April 26, 1991. Notice the impressive structure of the supercell (the V-notch and the hook).