Mesoscale Ensemble Prediction System (MEPS)−Based Guidance in JMA

The Japan Meteorological Agency (JMA) has responsibility for issuing weather warnings to mitigate natural disaster and forecasts to secure the safety of aviation operations. To support issuance of the information, we use guidance that is statistically calculated from the output of numerical weather prediction models. Therefore, more accurate guidance is necessary to provide precise information.

The Meso-Scale Ensemble Prediction System (MEPS) is being developed at JMA and has been implemented in test operation since March 2015. The MEPS-based guidance is also in test operation and is used by forecasters as reference information. The elements of guidance are precipitation amount, wind speed, temperature, snowfall amount, visibility, low cloud and probability of thunderstorms. The guidance of each ensemble member is calculated simply same as the deterministic forecast guidance. We validated the member's mean and probability density distribution and confirmed some improvements.

This presentation shows the outline of MEPS-based guidance, the result of forecast verification, and the usage.