Simulation of tornado over Orissa (India) on March 31, 2009, using WRF–NMM model

Abstract

A severe thunderstorm produced a tornado (F3 on the Fujita-Pearson scale), which affected Rajkanika block of Kendrapara district of Orissa in the afternoon of March 31, 2009. The devastation caused by the tornado consumed 15 lives and left several injured with huge loss of property. The meteorological conditions that led to this tornado have been analyzed. An attempt is also made to simulate this rare event using Non-hydrostatic Mesoscale Model (NMM) core of the Weather Research and Forecasting (WRF) system with a spatial resolution of 4 km for a period of 24 h, starting at 0000 UTC of March 31, 2009. The atmospheric settings resulted from synoptic, surface, upper air, satellite and radar echo studies were favorable for the occurrence of a severe thunderstorm activity over Rajkanika. The model-simulated meteorological parameters are consistent with each other, and all are in good agreement with the observation in terms of the region of occurrence of the intense convective activity. The model has well captured the vertical motion. The core of the strongest winds is shown to be very close to the site of actual occurrence of the event. The wind speed is not in good agreement with the observation as it has shown the strongest wind of only 20 ms⁻¹, against the estimated wind speed of 70 ms⁻¹. The spatial distributions as well as intensity of rainfall rates are in good agreement with the observation as model simulated 35.4 mm against the observed rainfall of 41 mm over Chandbali. The results of these analyses demonstrated the capability of high-resolution WRF–NMM model in simulation of severe thunderstorm events.