From Severe Weather Climatologies to the Impact of Cities, or What We Can Learn from 17 years of US Radar Composites

Radar data offer information on precipitation climatology that is simply not available or archived elsewhere: How often does it rain at any particular location? At what time? And with what intensity distribution? What are the geographical and temporal patterns of precipitation occurrence, formation, and decay? What is the climatology of severe weather? Answers to these questions have value on their own and also invariably trigger more questions about the processes causing these patterns as well as suggest some answers.

Here, U.S. composites of radar data from 1995 to 2013 are used to demonstrate the possibilities offered by such a data set. Three topics are touched: a) daily and annual cycles of precipitation, convection, and severe weather and what they can teach us about precipitation mechanisms; b) the influence of weekly activity cycles and of cities on precipitation and convection, and on the power and challenges of looking for a small signal in even such a large dataset; and c) the spatial and temporal distribution of the appearance of convection, and what it reveals on the importance of surface terrain properties for these events.>act 240001 modified by 132.206.246.51 on 8-8-2013-->