New report ( 26 pp.) by the Congressional Research Service on Severe Thunderstorms and Tornadoes in the U.S.: CRS on Storms May 2013. CRS Report # R40097.  The report addresses 3 issues: (1) forecasting and issuing warnings for several thunderstorms and tornadoes; (2) the role of mitigation; and (3) the effect of climate change.

Thanks to Bill Cumming for bringing this report to my attention.