SEASONAL PREDICTION OVER EAST ASIA FOR JUNE-JULY-AUGUST 2017 FOCRAII, Beijing 24~26 April 2017 SEASONAL PREDICTION OVER EAST ASIA FOR JUNE-JULY-AUGUST 2017 25 APRIL 2017 Tae-Kook Kim tkim@kwater.or.kr Water Resources Management Center

Contents Introduction of Water Resources Management Center in K-water Seasonal Prediction over East Asia for JJA 2017 II Summary III

K-water – Water Resources Management Center National organization for Integrated Water Management HUB of Water Management in Korea 35 dams 16 weirs 25 hydropower plants * 78 generator (1,061MW) 446 gauging stations 185 warning stations Facilities Head Quarter Command Center Imjin river Hangang Regional Head Office Han river Three Regional Head Office - Water Resources Management Center Geum river Nakdonggang Regional Head Office Nakdong river Dam Operation Team ICT Team Sumjin river Youngsan river Hydropower Generation Team Geum·Yeong·Seom Regional Head Office Meteorological Analysis Team

Meteorological Analysis Typhoon Forecast and Analysis Tasks of Meteorological Analysis Team Short-term Weather Forecast Long-term Seasonal Forecast 3 ㎞ × 3 ㎞ horizontal resolution 5 days (1 hour interval) rainfall forecast Quantitative rainfall over 33 multi-purpose dams and 16 weirs Operationally 4 times/1day forecast Long-range (3 months) seasonal prediction 50 ㎞ × 50 ㎞ horizontal resolution Analysis of Seasonal Pattern (Temperature and precipitation) Specialized over 16 Dam Basins Meteorological Analysis for Water Management Typhoon Forecast and Analysis 2 ㎞ × 2 ㎞ horizontal resolution Typhoon track and estimation of typhoon- influence region and its rainfall pattern Using dynamical typhoon prediction and statistical analysis method

MODEL for Long-term Seasonal Prediction CAM5.1.1 (CESM1.0.4) CESM Coupler Dynamical Core Dynamics : Finite Volume Horizontal coordinate : Gaussian grid Vertical coordinate : Lagrangian (‘floating’) vertical coordinate Time Stepping : Arakawa C and D horizontal staggering CAM Atmosphere CLM Land DOCN Ocean SST data Mode CICE Sea Ice Prescribed mode Coupler Physics scheme Shallow Convection : Park et al. (2009) Deep Convection : Neale et al. (2008) Microphysics : Morrison and Gettelman (2008) Macrophysics : Park et al. (2011) Radiation : Lacono et al. (2008) Aerosols : Modal Aerosol Model Ghan et al. (2011)

MODEL Configuration for the Ensemble Forecast Configuration for Seasonal Prediction Seasonal Prediction for JJA 2017 MODEL Configuration for the Ensemble Forecast Dynamics : Finite Volume Model : CAM5.1.1 / CESM1.0.4 Horizontal Resolution : About 50 km (0.47oⅹ0.63o) Ensemble Member : 10 members Ensemble Method : Lag Average Forecast Method Prediction Period : About 5 months from end of Mar. To Aug. (Spin-up : 2 months) Initial conditions : GFS Analysis fields (21st ~25th Mar. 00/12UTC ) Boundary conditions : Prescribed BDY from NOAA OI SST, Sea Ice concentration (NOAA OI weekly mean) Predicted Variable : 2m Temperature, Precipitation, Sea Level Pressure, Vertically Geopotential Height, Wind, etc. Physics scheme Shallow Convection : Park et al. (2009) Deep Convection :Neale et al. (2008) Microphysics : Morrison and Gettelman (2008) Macrophysics : Park et al. (2011) Radiation : Lacono et al. (2008) Aerosols : Modal Aerosol Model Ghan et al. (2011)

Prescribed SST Anomaly Sea Surface Temperature Anomaly (2017. 3. 15 ~ 21) Niño 4 Niño 3 Niño 1+2 Niño 3.4

IRI ENSO Forecast El Niño/La Niña Prediction for Summer 2017

Seasonal Prediction – Temperature 10 Days and Monthly Temperature Prediction at 850 mb Above normal until mid-June (before Changma season) Above normal in August

Seasonal Prediction – Precipitation 10 Days and Monthly Precipitation Prediction Above normal from end of June to early July (during Changma)

Possible Factors (1) – Expansion of WNPH North-Westward Expansion of Western North Pacific High (WNPH) June : Relative high over North Pacific  Development of WNPH  Higher temperature, Earlier Changma July : Persistence of high GP  Rainfall activation with strong intraseasonal variability August : Persistence of positive anomaly in GP over Kamchatka peninsula  Possibility of heat waves like last year (2016) Climatology Prediction

Possible Factors (2) – South-Westerlies with Moisture Strong South-Westerlies with More Moisture Flux at 850 mb Mid-June to early July : Supply more moisture over Korean Peninsula with strong south-westerlies August : Normal distribution due to the expansion of Western North Pacific High

Schematic Diagrams for This Seasonal Prediction During Changma Period (End-June – Mid-July) After Changma Period (August) Moisture Flux Geopotential Height anomaly Higher Temperature around East Asia Higher GP and Expansion west/northward More Moisture Flux  Activation of Changma Front Higher Temperature around East Asia More Higher GP along Southern China to Kamchatka Peninsula Persistence of Higher Temperature and occurring HWs Climatology Prediction of Geopotential Height

850 mb Temperature Prediction over Korean Peninsula Prediction for Every 10 days and months

Precipitation Prediction over Korean Peninsula Prediction for Every 10 days and months

Summary 2017 Summer prediction over Korean Peninsula Temperature Precipitation Jun Jul Aug Early 10 days 0/+ 0/- Middle 10 days + Last 10 days Monthly

Thank you