Hydro & Agro Informatics Institute (HAII) from Thailand operates the weather forecast based on regional climate model. They use Weather Research Forecast (WRF model) which is originally developed for research purpose while I think this could be useful for supplementary information to support forecasting and warning purpose.
High resolution maps (3km x 3 km) are available only for Thailand (covering most part of Lao PDR) in 3-day advance. The 5-day forecasted rainfall distribution is available across SEA at 9km x 9km.
The results show that heavy rainfall (red areas) will continue in central part of Lao until 31 Jul Please maps here:
http://www.thaiwater.net/v3/wrfroms/rain_forecast_pre/tab1/image2http://www.thaiwater.net/v3/wrfroms/rain_forecast_pre/tab1/image2
-- Chusit Apirumanekul