We use a multisensor gridded precipitation product to examine the interannual and intraseasonal variability of precipitating storms during the months of April – September of 1996 -2006 in the Arkansas-Red River Basin. We designate regions of contiguous precipitation (in space and time) which we consider to be individual storms.

Our data set has a total of 519,562 storms whose numbers vary by year and month. Storms are most numerous in the eastern and western extremes but the central part has the most precipitation. We find that the average storm is small with a maximum size under 500 km2 and a lifetime between 1 and 1.5 hours. Storms in August are smaller but longer lasting than those in April. The linear correlation between mean storm size and number of storms per year is -0.77.

Assuming all storms to be convective, we can divide the storms into single ordinary thunderstorms, multiple thunderstorms (includes supercells), and Mesoscale Convective Systems (MCS). The MCS are between 1 and 1.5% of all storms but account for about 85% of the precipitation. Nevertheless, the linear correlation between the number of MCS in each six month period and the total amount of precipitation in the period is only 0.42

In future work we plan to examine the spatial density of storms more thoroughly including spatial densities of different types of storms. We also intend to study variations in the initiation and termination times of these storms.