If you, like me, are interested in tornado activity in America this is the site to bookmark:

http://www.spc.noaa.gov/wcm/#data

This year, so far, looks unusually quiet for both thunderstorm and tornado activity.

The tornado count is less than 10% of average for this time in March, and the last three years have also well below storm activity.

Being NOAA they provide archives back to 1950, which as you can probably guess I have already downloaded and written a viewer for, but I have my work cut out for me with this kind of data, because this site is chock-a-block with all kinds of statistics that I can't begin to match. Because a lot of people die each year as the result of these events (47 last year with 632 injured) NOAA take the whole matter of forecasting and issuing 'watches' for them very seriously.

Why thunderstorm and tornado activity is so low at the moment is debatable, and it will be interesting to see how the rest of 2015 pans out.