During satellite launch operations, accurate weather predictions and reliable information on the winds, wind-shears and thunderstorm activities over the launch site happens to be of paramount importance in the efficient management of launch time operations. Therefore, effective utilisation of the current observations (surface and upper-air observations, Radar and satellite) is highly essential to forecast imminent weather events over the launch site and to warn if necessary.

With a view to providing the short-range weather predictions over Sriharikota, the Space Physics Laboratory (SPL) of VSSC made a humble beginning in 1999-2000, when it installed a mesoscale non-hydrostatic atmospheric model, namely - the Advanced Regional Prediction System (ARPS) on the IBM mainframe and made it operational for extracting the time-series of vertical profiles of different atmospheric parameters for +12 hrs over the SHAR region. The ARPS model-simulated products were effectively utilised in the launch operation management by the SDSC, SHAR (MET-Facility) as this model had capability of generating the initial conditions through 1-dimensional vertical profiles of basic meteorological parameters obtained through balloon-borne GPS sonde ascents conducted at SHAR itself.Having gained sufficient expertise in the ARPS model simulations in research mode; the SPL ventured into the assimilation of radial winds and reflectivity data gathred through Doppler Weather Radar (DWR) at SDSC, SHAR in 2007-2008. Indigestion of DWR data into the ARPS model was one of the highly desired requirements from SDSC, SHAR and this initiative of SPL fructified into highly reliable nowcasting during the thunderstorm events.

With a growing need for having a reliable information on the local weather over SHAR, and formation of cyclones over the Bay of Bengal and its plausible impact on SHAR, the SPL extended its efforts on short-range weather predictions by augmenting a new hydrostatic atmospheric model, namely - the High-resolution Regional Model (HRM) over a larger domain centred around SHAR. The HRM model makes use of initial and lateral boundary conditions of a German global model and is presently operational at SPL for providing forecasts at a spatial resolution of about 5 kms. The SPL has also developed a new surface-layer parameterization scheme in this model, which is more suitable for simulation of sensible heat flux compared to its default scheme. By making use of a non-hydrostatic (ARPS) and a hydrostatic (HRM) atmospheric model, the SPL started supporting the satellite launch operations by providing the model-simulated forecast products for SHAR ever since GSLV-F01 launch (20 September 2004).

As part of the first Indian Lunar mission (Chandrayaan-1), the Satish Dhawan Space Centre (SDSC), SHAR constituted a Inter-Centre Weather Forecast Expert Team for the PSLV-C11 mission. This expert team was primarily responsible for providing forecast information of low pressure systems in the Bay of Bengal concerned to SHAR, for the next 72 hours and clearance for start of countdown activities. As the Chandrayaan-1 mission was scheduled in October 2008, when the onset of NE-monsoon over SHAR lead to frequent thunderstorms, lightning and associated rainfall events. During this mission, SPL played a pivotal role in nowcasting through ARPS and HRM model simulations and its efforts were widely appreciated by the project team. Since the first constitution of a Weather Forecast Expert Team in 2008, the SPL is continuously representing this team as an active partner by providing short-range weather predictions for PSLV and GSLV missions. Since PSLV-C11 (Chandrayaan-1) mission, the SPL has participated in all the PSLV/GSLV campaigns including the very latest Mars Orbiter Mission which lifted off successfully on 5th November 2013. Being one of the serving members of the Weather Forecast Expert Team, SPL is committed to deliver the best-possible information to all the satellite launch campaigns in future by providing the desirable forecast products to the PSLV/GSLV projects.



(1) Radhika Ramachandran, U. C. Mohanty, Sujata Pattanayak, M. Mandal and S. Indira Rani: "Location- specific forecast at Sriharikota during the launch of GSLV-F01", Current Science, 91(3), 285 - 295, 2006.

(2) Radhika Ramachandran: "DWR Data Assimilation in Numerical Weather Prediction for Forecasts of Thunderstorms at Sriharikota", Technology Development for Atmospheric Research and Applications pp. 463 - 487, 2008.

(3) Subrahamanyam, D. B., Ramachandran, R. and Kunhikrishnan, P. K.: "Improvements in Simulation of Atmospheric Boundary Layer Parameters through Data Assimilation in ARPS Mesoscale Atmospheric Model", Remote Sensing and Modeling of the Atmosphere, Oceans, and Interactions, Proc. of SPIE 6404: 64040K. 

(4) Subrahamanyam, D. B., Rani, S. I., Ramachandran, R. and Kunhikrishnan, P. K.: "Nudging of Vertical Profiles of Meteorological Parameters in One-Dimensional Atmospheric Model: A Step Towards Improvements in Numerical Simulations", Ocean Science Journal 43(4): 165 ? 173, 2008.

(5) Subrahamanyam, D. B., Ramachandran, R., Anurose, T. J. and Mohan, M.: "Short-to-Medium Range Weather Forecasting for Satellite Launches: Utilization of NWP Models in conjunction with the Earth Observing Systems", Bulletin of National Natural Resources Management System, NNRMS(B) - 35: 37 - 49, 2010.

(6) Subrahamanyam, D. B., Ramachandran, R., S. Indira Rani, S. Sijikumar, T. J. Anurose and Asish Kumar Ghosh: "Location-specific weather predictions for Sriharikota (13.72°N, 80.22°E) through numerical atmospheric models during satellite launch campaigns", Natural Hazards, 61:893-910, 2012.