1 Japan Meteorological Business Support Center, Tokyo101-0054 Japan;

2 National Center for Hydro-Meteorological Forecasting, Hanoi 10000, Vietnam;

*Corresponding author: k–; Tel.: +81–352810440


Development of forecast guidance is one of main activities of Output 3 of the JICA Project to improve forecasting services of VNMHA. Maximum and minimum temperature guidance was developed for 63 cities up to 10 days ahead in the first phase of the Project. Development of precipitation guidance was the primary activity of Output 3 in the second phase of the Project. Statistical analysis on 24-hour rainfall observations and predictions by JMA GSM and ECWMF IFS showed that the correlation between them was low for each station but relatively high for each region. Preliminary investigation of POP trial guidance calculated with logistic regression and multiple linear regression for 4 stations and 4 regions showed the verifications scores (BSS: Brier Skill Score) for regional POP were considerably higher than those for station POP. IFS-GSM-integrated precipitation guidance was developed to improve regional mean/max rainfall guidance and had slightly better verification results than IFS and GSM precipitation guidance. Based on these verification results, precipitation guidance on regional POP and regional mean and max for 12-hour rainfall (tonight and tomorrow daytime) and for 24-hour rainfall (after that) was developed for 36 regions in Vietnam up to 5-days ahead. Precipitation guidance was generally able to predict a reasonable amount of rainfall for heavy rain events caused by tropical cyclones in 2022, however there were several heavy rain events where IFS and GSM rainfall predictions were quite low, and rainfall guidance was also quite low.


Cite this paper

Sasaki, K.; Anh, V.T. Development of precipitation guidance for 36 regions in Vietnam up to 5 days ahead. J. Hydro-Meteorol. 2023, 15, 40-58. 


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