Case Studies of Severe Storms during HWT 2013 Using Variational LAPS

The Experimental Warning Program (EWP) is part of NOAA's Hazardous Weather Testbed (HWT) and held annually at spring time at the National Weather Center. In Spring 2013, several tornadoes touched down, including the deadly EF5 Moore tornado that killed 24 people and caused millions of dollars damage on 20 May 2013. In this paper, we will introduce the sophisticated numerical data assimilation and forecast system called Local Analysis and Prediction System (LAPS), and the new, variational version of LAPS. We will select several cases of supercell storms and tornadoes to highlight the real-time performance of variational LAPS including some feedback from forecasters who used variational LAPS together with other available numerical guidance to provide experimental warnings.