you need to click on the NEXRAD box above the 'Today's' in the red banner..just below the blue box with the magnifying glass in it.
then click on a white cross near you.. you can then above the weather box is pan, click to center a point then click magnify to get a good close view if a tornado is near.. i go dow to about 6 mile resolution.. ti has the roads etc.. we watched a tornado pass us by about 3 miles..we could have see it on the map to about 1/4 mile..or less
you can click multiple frames and animation speed, the number of storms.. which will show hail/wind/tornado/amount of rain.. you will have re-click go to advance after about 10 minutes
i hope you find this helpful... i have shortcut on my desk top
http://www.wunderground.com/index.html