Simulation of hailstorm event using Mesoscale Model MM5 with modified cloud microphysics scheme

摘要

Mesoscale model MM5 (Version 3.5) with somemodifications in the cloud microphysics scheme of Schultz (1995), has beenused to simulate two hailstorm events over Gangetic Plain of West Bengal,India. While the first event occurred on 12 March 2003 and the hailscovered four districts of the state of West Bengal, India, the secondhailstorm event struck Srinikatan (22.65° N, 87.7° E) on 10 April 2006 at11:32 UT and it lasted for 2–3 min. Both these events can be simulated,if the same modifications are introduced in the cloud microphysics scheme ofSchultz. However, the original scheme of Schultz cannot simulate any hail.The results of simulation were compared with the necessary products ofDoppler Weather Radar (DWR) located at Kolkata (22.57° N, 88.35° E).Model products like reflectivity, graupel and horizontal wind arecompared with the corresponding products of DWR. The pattern of haildevelopment bears good similarity between model output and observation fromDWR, if necessary modifications are introduced in the model. The modeloutput of 24 h accumulated rain from 03:00 UT to next day 03:00 UT hasalso been compared with the corresponding product of the satellite TRMM.