Tropical Cyclone Ensemble Forecast Information HomePage


1. Purpose

The purpose of this homepage is to provide a guidance of tropical cyclone forecasts in near real-time for the Economic and Social Commission for Asia and the Pacific (ESCAP)/the World Meteorological Organization (WMO) Typhoon Committee Members and forecasters participating in the Sever Weather Forecasting Demonstration Project (SWFDP) in Southeast Asia, based on the THORPEX Interactive Grand Global Ensemble (TIGGE) Cyclone XML (CXML) data, under the joint project of World Weather Research Program (WWRP) and Tropical Cyclone Program (TCP); North Western Pacific Tropical Cyclone (TC) Ensemble Forecast Project (NWP-TCEFP). The data providers are shown here. The homepage is also set up for interested researchers to develop the TIGGE related applications/products for tropical cyclone studies. Commercial use of the data is not allowed. The homepage is password protected. You can send a request with your information to get ID and password to

2. Background

The WMO North Western Pacific Tropical Cyclone (TC) Ensemble Forecast Project (NWP-TCEFP) intends to build on the TIGGE concept and take advantage of the TIGGE CXML data provided by multiple organizations for improving TC track forecast skill over the North western Pacific. The project was launched as a 5-year project in 2009, following a suggestion at the 42nd session of the ESCAP/WMO Typhoon Committee (Singapore, 25–29 January 2010). The objectives of the NWP-TCEFP are

- to explore and develop effective ways of obtaining and utilizing the track forecast data from TIGGE data providers to improve medium range forecast of TC track forecast

- to develop software for a real time multi-model tropical cyclone forecasting system from data transfer to verification

- to evaluate the utility of multi-model forecasts of tropical cyclones track predictions and provide recommendations on future multi-model ensemble systems and on future GIFS-RDPs

- to encourage forecasters of involved Members to utilize the information on this Web and to exchange their experience in use of TIGGE ensembles data for tropical cyclone forecast via "Discussion" page.

In line with the Annual Operating Plan (AOP) of the Working Group on Meteorology (WGM) of the ESCAP/WMO Typhoon Committee for 2013, the NWP-TCEFP evaluated tropical cyclogenesis prediction over the North Western Pacific on medium-range timescales. The NWP-TCEFP was extended to 2015 at the 16th session of the Commission for Atmospheric Sciences (CAS)/WMO in Turkey, 20–26 November 2013 for the purpose of investigating tropical cyclogenesis prediction over the North Western Pacific on medium-range timescales.

  • Yamaguchi, M., T. Nakazawa, and S. Hoshino, 2015: North Western Pacific Tropical Cyclone Ensemble Forecast Project, Tropical Cyclone Research and Review (In Print)
  • Yamaguchi, M., T. Nakazawa, and S. Hoshino, 2012: On the relative benefits of a multi-centre grand ensemble for tropical cyclone track prediction in the western North Pacific, Q.J.R. Meteorol. Soc., 138, 2019-2029.
  • 3. Outline

    The homepage provides the following information.

    - Deterministic and Ensemble TC track forecasts.

    - Strike Probability Map (if a TC will approach within 120 km range in certain periods (currently 4 days) , based on Ebsemble TC track forecasts, with three different ways ("In 4 days", "each time", and "time series at cities")

    - For verification purposes, the best track data by JMA are enbedded on the forecast track and strike probability maps.

    Sample Page

    4. Special thanks to

    - data providers, who officially agreed to use the CXML data in near real-time for this homepage.

    - THORPEX International Project Office, which sent the request to all data providers, to agree with the data utilization under the project, "North western Pacific Tropical Cyclone Ensemble Forecast Project".

    - David Parsons, who always encourages us to initiate/develop/implement the project.

    - Elizabeth Ebert, who gave us invaluable comments to improve the page.

    - GIFS-TIGGE Working Group Co-Chairs, Zoltan Toth and Richard Swinbank, who always encourage us to establish the page.

    - Koji Kuroiwa, who offerred to send out the letter to the Typhoon Committee members to annoumce the opening of this homepage.

    - RSMC Tokyo, that kindly provided the sourse code of the tropical cyclone forecast homepage for the Typhoon Committee members.