New Forecast Technologies for Disaster Prevention and Mitigation

New Forecast Technologies for Disaster Prevention and Mitigation 1 C：Asia Air Survey co. , ltd JMA Takayuki MATSUMURA (Forecast Department, JMA)

2 Missions of JMA To protect life and property from natural disasters such as floods, landslides, debris flows, storms, etc. Development of a Numerical Weather Prediction system Based on physical lows Beyond several hours Accurate prediction of timing and location of severe weather events Accurate prediction of typhoon tracks Development of a Nowcast system Based on a heuristic method Up to a few hours Accurate prediction of timing and location of precipitation

What is Numerical Weather Prediction ? Super-computer Observation Initial Condition Numerical Model Physical laws Prediction Precipitation, Temperature, Winds. . Schematic illustration of Numerical Model 3

Current Operational Numerical Models • Typhoon model • Horizontal Resolution: 24 km • Updates: 4 times a day • Global model • Horizontal Resolution: 60 km • Updates: 2 times a day Mesoscale model Horizontal Resolution: 10 km Updates: 4 times a day Regional model Horizontal Resolution: 20 km Updates: 2 times a day 4

5 Requirements for Numerical Weather Prediction Numerical Model Development of models Advanced mesoscale model fully-compressible non-hydrostatic equation, cloud microphysics Initial Condition Use of various observational data Satellites, Wind profiler, Aircraft, Doppler radar, . . Development of data assimilation Advanced assimilation method Improved Performance

6 Impact of the New Model Mesoscale Model Forecast of Heavy Rainfall Observation New Model Old Model Rain Rate (mm hr-1) The new model shows better performance as compared to the old model. Rain Rate at the surface resulting from Baiu front at 15 JST, 19 July 2003.

Observation Data Used in the Analysis A high-resolution model requires dense observations with sufficient accuracy. 7

8 Performance of the Mesoscale Model a dat ethod a r m t dat ile f a a pro lation craf dat l d dat i r n e e im ed ai wi llit ode s llit e e ic as at sat w m sat est w m e om a n auto new a ne new d Accuracy of precipitation forecasts is represented by an objective index indicating the minimum (0) to the maximum (1). Forecast Skill Precipitation Forecast for Rain-rate at 10 mm / 3 hr

Impact of Horizontal Resolution of the Model As the horizontal resolution increases, the rain band is well represented. Observed Rain Rate 1. 5 -km 10 -km Three-hourly accumulated rainfall for 09 – 12 JST. Maximum rainfall amounts attained over 60 mm/hour. 9

10 Typhoon Positional Error of Typhoon Model Forecasts FT = 72 hours FT = 48 hours FT = 24 hours Forecast errors of typhoon center positions are reduced, especially for longer forecast hours, resulting from model developments.

Nowcasting of Precipitation Very Short Range Forecast Nowcast nowcast represents localized high rain rates 1 -hour rainfall res. =5 km, issued every 30 min up to 6 hours 10 -minutes rainfall res. =1 km, issued every 10 min up to 1 hour Disaster prevention and mitigation • Urban flood caused by a rapidly developing rain cloud 11

Future Plan 12 Development of a high-resolution model Horizontal resolution: 2 ~ 5 km Further improvement of Typhoon forecast with new technologies Multi-scale analysis of echo motion for nowcasting Improve the forecasts of severe meteorological phenomena that threaten life and property.

Summary A role of JMA is to provide accurate forecasts for prevention and mitigation of natural disasters. Enhancement of the numerical weather prediction system and nowcast system is an important task. • Development of an advanced mesoscale model • Use of various observational data • Development of an advanced data assimilation method • Improvements in the typhoon track forecasts • Development of Very-Short-Range Precipitation forecasts including Nowcasting 13

14 謝謝 Thank you. Merci. Спасибо Gracias. ありがとうございました。