Seasonal-Interannual Predictions of Summer Precipitation Over the Tibetan Plateau in North American Multimodel Ensemble

Variations of precipitation over the Tibetan Plateau (TP) have great hydrometeorological impacts on local and surrounding areas. Focusing on the TP precipitation in the boreal summer, this study investigates the seasonal-interannual predictions of eight dynamical models from the North-American Multi-Model Ensemble (NMME) using different observational data sets for verification. Results show dynamical prediction skill of the TP precipitation is regionally dependent with significantly high skills in the southwestern TP up to about three-season ahead. Prediction skill of precipitation anomalies over the southwestern TP is significantly reliant on the models' ability in reproducing the observed relationship between the anomalous southwest-TP precipitation and Pacific Sea surface temperature (SST). Using the different gridded observational data sets as verifications can lead to variations in prediction skills, and the multi-observation mean tends to obtain the highest skills over the southwestern TP. These results provide a deeper understanding of dynamical seasonal-interannual predictability of summer precipitation in TP.

Automated summary

This study investigates the seasonal-interannual predictions of summer precipitation over the Tibetan Plateau and finds that the prediction skill varies regionally, with the southwestern part of the plateau having higher skill. The skill of predicting precipitation anomalies in this region relies on the models' ability to reproduce the observed relationship between the anomalies and Pacific Sea surface temperature. Using multiple observational datasets for verification can lead to variations in prediction skill, with the multi-observation mean performing best in the southwestern Tibetan Plateau.