Table of Contents
ISRN Meteorology
Volume 2012, Article ID 523942, 21 pages
Research Article

A Comparative Study on Performance of Analysis Nudging and 3DVAR in Simulation of a Heavy Rainfall Event Using WRF Modeling System

1National Centre for Medium Range Weather Forecasting (NCMRWF), A-50, Sector 62, Noida 201 309, India
2Environmental Modeling Center, National Centers for Environmental Prediction (NCEP), 5200 Auth Road, Camp Springs, MD 20746, USA
3Centre for Atmospheric Sciences, Indian Institute of Technology, Delhi, New Delhi, Hauz Khas 110 016, India
4Statistical Research, Skymet Weather Services, Noida, 201 307, India

Received 1 April 2012; Accepted 29 May 2012

Academic Editors: L.-T. Hsieh, K. Nakamura, Z. Pu, F. Tao, and D.-Y. Wang

Copyright © 2012 Ashish Routray et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The present study focuses on the performance-based comparison of simulations carried out using nudging (NUD) technique and three-dimensional variational (3DVAR) data assimilation system (3DV) of a heavy rainfall event occurred during 25–28 June 2005 along the west coast of India. The Indian conventional and nonconventional observations are used in the 3DV experiment. Three numerical experiments are conducted using WRF modeling system, the model is integrated upto 54 hours from the initial time 0000 UTC of 25 June 2005. It is noticed that the meteorological parameters are improved in the resulting high-resolution analyses prepared by NUD and 3DV compared to without data assimilation experiment (i.e., called CNTL experiment). However, after the successful inclusion of observations using the 3DVAR data assimilation technique, the model is able to simulate better structure of the convective organization as well as prominent synoptic features associated with the mid-tropospheric cyclones (MTC) than the NUD experiment and well correlated with the observations. The simulated location and intensity of rainfall is also improved in 3DV simulation as compared with other experiments. Similar results are noticed in the root mean squar errors, correlation coefficients, and Equitable Threat Scores between TRMM and model simulated rainfall for all the three experiments.