International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 22 (2017) pp. 12645-12651 © Research India Publications. http://www.ripublication.com 12645 Impact of Physics Parameterization Schemes in the Simulation of Laila Cyclone Using the Advanced Mesoscale Weather Research and Forecasting Model P. Janardhan Saikumar 1 Research Scholar, Department of Electronics and Communication Engineering, Sri Venkateswara University College of Engineering, Sri Venkateswara University, Tirupati, Andhra Pradesh, India. Orcid Id: 0000-0003-2307-8786 Dr. T. Ramashri 2 Professor, Department of Electronics and Communication Engineering, Sri Venkateswara University College of Engineering, Sri Venkateswara University, Tirupati, Andhra Pradesh, India. Abstract The severe Tropical Cyclone Laila caused extensive damage and loss of life in southeastern India during May 2010. The cyclone developed from a low-pressure system that formed under the influence of an upper-air cyclonic circulation in the Bay of Bengal and intensified into a Severe Cyclonic Storm. The cyclone reached its peak intensity with a minimum central pressure of 974 mbar and reached the maximum sustained wind speed of 120 km/h (64.8 Knots). The cyclone crossed the Andhra Pradesh coast near Bapatla between 1100 and 1200 UTC on May 20. In this present study, the sensitivity of numerical simulations of tropical cyclone Laila to physics parameterizations is carried out with a view to determining the best set of physics options for prediction of cyclones originating in the north Indian Ocean. The latent heat released in the clouds plays very important role in intensifying or strengthening of Tropical cyclones and the latent heat release is mainly dependent on the cloud microphysical and dynamical properties. Three nested domains are considered for WRF model simulation. The resolution of domain-1, domain-2, and domain-3 are 45 km, 15km, and 5 km respectively. The results from the domain-3 are considered for analyzing and comparing the results. Model simulation outputs are compared with corresponding observation data. The simulated track and intensity of tropical cyclone Laila are compared with the real-time data provided by the Joint Typhoon Warning Centre (JTWC). WRF model Simulations are performed using different convective cumulus parameterization (CU) and microphysics parameterization (MP) schemes. The main purpose of the present study is to find the best suitable combination of MP and CU schemes for the simulation of an accurate track of severe tropical cyclone Laila over the Bay of Bengal. It was observed that in the mesoscale model the track and intensity prediction skill predominantly depends on CU and MP parameterization schemes. Keywords: Laila, WRF Model, physics parameterizations, Cyclone track, Track error INTRODUCTION The Very Severe Cyclonic Storm Laila developed from a low- pressure area over North Indian Ocean late on 17th May 2010 and intensified into Cyclone Strom on 18th May and further intensified into a Very Severe Cyclonic Storm (VSCS) in the early morning of 19th May. It continued to intensify while moving north-west direction and reached maximum intensity with a maximum sustained wind speed (MSW) of 120 kmph over the Bay of Bengal of Andhra Pradesh coast on 20th May 2010. It crossed south Andhra Pradesh coast near Bapatla 16.0°N 80.6°E between 1100 and 1200 UTC on 20th May. At the time of landfall on 20th the estimated central pressure was 974 hPa (JTWC 2010) and the estimated maximum sustained surface wind speed was about 70 Knots. It caused very heavy to extremely heavy rainfall over South Andhra Pradesh. Ongole received heavy rain of 32 cm on May 20 and 142 mm on May 21in Andhra Pradesh. On May 21, in 24 hours kothapatnam received rainfall of 258 mm, Maddipadu received rainfall of 510 mm and Addanki received the highest rainfall of 522 mm [1]. The numerical weather prediction (NWP) and dynamical statistical models provided good guidance with respect to its genesis, track, and intensity. The India Meteorological Department (IMD) and the Joint Typhoon Warning Centre (JTWC), USA predicted the genesis, intensity, track, point and time of landfall 5 days in advance. Cyclones developed over warm oceans and under the influence of steering forces cyclone move towards the land [2]. In recent years Indian Meteorological Department adopted various strategies and decision-making process to improve the prediction of tropical cyclones [5]. Different simulation experiments are conducted to examine the performance of the high-resolution Advanced Research Weather Research and forecasting model for tropical cyclone prediction over the Bay of Bengal (BOB) region of the northern Indian Ocean (NIO) [11]. Several experiments conducted to study the impacts of cloud microphysical processes on hurricane track, intensity, precipitation and thermodynamic vertical structural characteristics of hurricane