Hyun-Cheol Shin, National InstituteĀ of Meteorological Science/Korea Meteorological Administration

Recent Improvements of KMA Regional Data Assimilation System for better forecast of severe weather over East Asia.

Hae-Mi Noh, Dong-Joon Kim, Tae-Kyu Jang, Eun-Hee Lee, Sangwon Joo


Several key elements in KMA's regional 4DVAR system and model, which has 12 km resolution and covers East Asia region, were modified to provide better forecast. In spite of general improvement of performance that regional model showed since KMA introduce Unified Model from UKMO in 2010, regional model sometimes produced wrong forecast for the specific severe weather case.

The wrong forecast cases were reviewed and typhoon bogus system, surface analysis,and satellite data thinning were changed based on review results. Typhoon bogus points were optimally relocated and QC criteria for bogus data were changed. Also, thinning ranges for ATOVS, IASI and AIRS were changed based on sensitivity test results. Regarding surface analysis, soil moisture input data were more frequently updated from once a day to 4 times a day. With these improvements, model performance was improved about 4.9 % maximumly and typhoon forecasts for Nakri and Halong case were greatly improved.

In this study, what was modified will be discussed and main results from these modifications will be shown.

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