In the earlier period of the campaign, the background zonal wind was easterly, because the Madden-Julian Oscillation (MJO) stayed over the Indian Ocean, and the precipitation system migrating to the west was frequently observed. After the middle of December, the MJO passed over the MC region, and the background zonal wind turned to westerly. Following the change of the zonal wind direction, the precipitation system migrating to the east was dominant.
Figures show the mean diurnal cycle of the surface precipitation simulated by SCALE with coarser (a. 17.5 km) and finer (b. 3.5 km) horizontal resolutions. Numerical simulations successfully captured the diurnal cycle of precipitation over the land, and the migration of the precipitation systems was well reproduced during both periods in terms of the direction. However, the migration speed was different among the simulations. From some sensitivity tests, it is concluded that the horizontal resolution of the model is most critical to reproduce the realistic migration speed.