1. Overview of KMA s Operational LRF Services 2011. 12. 02 Korea Meteorological Administration

2. Long-range Forecast at KMA 1-month Forecast 3-month Forecast 6-month Forecast Issue Date 3 rd, 13 th, 23 rd of each month 23 rd of each month 23 rd of Feb., May, Aug., and Nov. Ensemble members 20 members both for the HCST and FCST Hindcast Period: 1979-2010 Simulation Period 230 days with about 3 weeks lead time Forecast type Deterministic three-categories based on model climatology 3-level probability Contents Temperature and Precipitation (10-day mean, 30-day mean) Temperature and Precipitation (1-month mean, 3-month mean) Asian dust (Feb) Typhoon (May, Aug) Seasonal mean Temp./Precip.

3. Forecast period X Issue date 1-month forecast3-month forecast F 10 20 M 10 20 A 10 20 M 10 20 J 10 20 J 10 20 A 10 20 S x Seasonal outlook x x Forecast Period Issue date Initial data(5days 6hourly=20mem) SST forecast 3 rd 13 th to 17 th × 13 th 23 rd to 27 th × 23 rd 3 rd to 7 th monthly data

4. The Current Long-Range Forecast System

5. GDAPS Configuration Model nameGlobal Data Assimilation and Prediction System (GDAPS) Implementation, system1999, Tier-2 forecast system Model resolutionT106/L21 Atmospheric ICNCEP Reanalysis 2 Ocean ICMonthly OISST v.2 SST prediction (Tier2)Predicted SST using dynamical/statistical prediction model Hindcast Period1979-2010 Ensemble size20 Member for both hindcast and forecast Ensemble configuration00, 06, 12, 18Z of 5 th days (3~7, 13~17, 23~27 of each month) Length of forecasts230 days Data formatGRIB 1 Forecast anomalies construction Lagged average method with about 15-day forecast lead time

6. ENSO Forecast KMA El-Nino Model Statistical method Statistical method Statistical method Ensemble Process Based on Cross-validation - Calculate Hindcast Skill of 4 models at each grid point - Exclude models which Hindcast Skill is below than certain threshold. - Simple Ensemble Mean for the qualified models - Superior to other Ensemble Technique (Multiple Regression, Best Model)

7. Future Plan Joint Seasonal Forecasting system by KMA and Met Office Based on GloSea5 (N216L85+O1/4L75) or GloSea4 (N96L85+O1L75) - Jan. ~ Jun. 2012: Set up GloSea5 at CRAY(KMA) - Jun. 2012: Semi-operational run. - Jun. 2013: Operation of the new system! Probabilistic forecasts for both sub-seasonal and seasonal forecasts - Tsfc, Precip - considering Tmin and Tmax (extreme events ?)