All WSR-88D scanning strategies start volume scan coverage at the lowest elevation angles. Thus, radar data from the lowest scans of precipitating systems can be five or six minutes old at the completion of a volume scan when severe weather features are typically identified. This can produce a critical time lag between the observation of radar signatures and their identification by radar-derived algorithms. Agencies such as the National Weather Service and Federal Aviation Administration could obviously benefit from faster access to severe weather algorithm output within their respective warning decision procedures.

The National Severe Storms Laboratory has produced a rapid update capability within its Severe Storm Analysis Package to improve the timeliness of severe weather warnings. The rapid update capability allows severe weather algorithm output to be updated at the conclusion of each elevation scan instead of the end of a volume scan. Specifically, four NSSL algorithms have been equipped with a rapid update capability: the Storm Cell Identification and Tracking algorithm; Hail Detection Algorithm; Tornado Detection Algorithm; and Mesocyclone Detection Algorithm.

The rapid update system is being tested for robustness and accuracy at this time for potential inclusion within the WSR-88D Open System and is currently slated for implementation within Open Radar Product Generator Build 5.0. A rapid update capability should allow forecasting agencies to increase tornado and severe weather warning lead time.