Guidelines on Seasonal Hydrological Prediction (WMO-No. 1274)

The Guidelines on Seasonal Hydrological Prediction have been published!

Information presented in the Guidelines will assist with planning and development of hydrological outlooks by NMHSs and WMO Members, as WMO is aiming to assist to develop their capabilities to deliver water information services, through its ambitious and long‑term Global Hydrological Status and Outlook (HydroSOS) project, including sub‑seasonal and seasonal hydrological predictions at the global, regional and river basin scales.

The document is structured into nine chapters and focusses on streamflow forecasting at lead times beyond the flood time range of 2 to 3 days. The contents are the following:

  • Chapter 1 provides context on SHP services.
  • Definitions and understanding of SHP services across various time ranges are discussed in Chapter 2, which includes a generic description of sources of predictability underpinning SHP services provided for long lead times.
  • Key considerations for developing and delivering SHP services at the national level, and user needs are discussed in Chapter 3 and Chapter 4 respectively.
  • Chapter 5 describes methods that can potentially be used for developing new or upgraded SHP services.
  • Data requirements for large-scale SHP services are discussed in Chapter 6.
  • The concepts and metrics required to assess forecast performance are discussed in Chapter 7.
  • Operational systems required for delivering SHP services can potentially be of varying levels of complexity: concepts related to forecast and modelling systems are discussed in Chapter 8.
  • Information discussed in these Guidelines is summarized in Chapter 9, which includes a brief description of challenges and likely future development priorities for SHP services.

You can access the full guidelines here: Guidelines on Seasonal Hydrological Prediction (WMO-No. 1274 | E-Library (