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Forecast Verifications Standardised Verification System for Long-Range Forecasts

Standardised Verification System (SVS)


Long-range forecasts are being issued from several Centres/Institutes and are being made available in the public domain. Forecasts for specific locations may differ substantially at times, due to the inherent limited skill of long-range forecast systems. The Commission acknowledged the scientific merit of those differences and encouraged the various approaches as a means to spur progress on the research front. However, concerns were raised that this situation tended to lead to confusion amongst users, and ultimately was reflecting back on the science behind long-range forecasts. There was agreement on the need to have a more coherent approach to verification of long-range forecasts. The Commission agreed that its role was to develop procedures for the exchange of verification results, with a particular focus on the practical details of producing and exchanging appropriate verification scores.This document presents the detailed specifications for the development of a Standardised Verification System (SVS) for Long-Range Forecasts (LRF) within the framework of a WMO exchange of verification scores. The SVS for LRF described herein constitutes the basis for long-range forecast evaluation and validation, and for exchange of verification scores. It will grow as more requirements are adopted.