Evaluation of clouds simulated by a weather model over western India

ABSTRACT

Cloud is one of the most crucial parameters, which influences the predictive ability of the weather models. This study is first of its kind to assess the efficiency of the numerical weather prediction (NWP) models to simulate the cloud types over Indian region. Two broadly used NWP models named as European Centre for Medium Range Weather Forecast (ECMWF) Reanalysis Interim (ERAI) and Weather Research and Forecasting (WRF) model are chosen to compare analyses and forecasts of cloud types along with cloud base height (CBH) measured from ceilometer over Ahmedabad (23.03°N, 72.5°E, 55 m amsl), India. Three months of the Indian summer monsoon period (July to September, 2014) are used for initial verifications. Results show that both the ERAI and WRF models are able to capture the cloud cover correctly over this region. This investigation has shown that the WRF model shows mostly mid-level cloud as low-level cloud, which needs further modification in WRF physics to improve the skills of cloud forecast. Further investigations of temporal variations of clouds and rainfall from in situ observations reveal that low-level multi-layer clouds provide favourable environment for rainfall.

Acknowledgements

Authors are grateful to National Center for Atmospheric Research (NCAR) for WRF Model. The global model analysis available from National Centers for Environmental Prediction (NCEP) is acknowledged. Our thanks are due to the ERAI reanalysis team members (http://apps.ecmwf.int/).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by ISRO GBP programme for providing instruments and also supported by Department of Space, Government of India.