Workshop on Predictability, dynamics and applications research using the TIGGE and S2S ensembles

The Japan Meteorological Agency (JMA) operates the Global Ensemble Prediction System (GEPS) to support issuance of Five-day Tropical Cyclone (TC) Forecasts, One-week Forecasts, Two-week Early Warning Information on Extreme Weather, and One-month Forecasts. In this study, we indicate the performance of JMA-GEPS prediction for the extremely warm days over Asia in spring 2018.
In February 2018, Japan experienced cool days, and it followed by extremely warm days in March. This change was linked to the change in the upper troposphere. Namely, negative anomalies at 500hPa covered over Japan around the middle of February, but positive anomalies extended westward gradually from the Bering Sea. In other words, this change was potentially supported by the wave pattern over Eurasia in the troposphere and the energy propagation from stratosphere as well.
JMA-GEPS successfully predicted this change from cool days to extremely warm days with the lead time of 2-3 weeks. The wave energy propagation and the wave patterns were also represented well in the troposphere. In this presentation, results from the several numerical weather prediction center obtained from the TIGGE and S2S databases will be also shown.