中文摘要：

延伸期预报介于中期天气预报和短期气候预测之间,对开展防灾、救灾工作具有极其重要的意义,同时又是具有相当难度的科学问题.延伸期时间尺度虽然超过逐日天气预报时效理论上限,但仍然存在可预报的气象场特征.回顾了月动力延伸预报的发展历程和最新进展.基于大气系统的混沌特性,重点回顾和总结了延伸期的可预报性、历史资料在月动力延伸期预报中的作用和延伸期集合预报方法等方面的研究进展.

英文摘要：

The extended-range forecasting (ERF) fills the gap between medium-range weather forecasting and short-range climate forecasting. It plays an important role in disaster prevention and reduction, and it is often considered a difficult scientific problem. Although extended-range forecasting has exceeded the limit of daily predictability of weather, there are still partially predictable characteristics in such forecasts. Both history and development studies on dynamical extended-range forecasting (DERF) are reviewed. Based on chaotic characteristics of the atmosphere, extended-range predictability, the role of historical data in DERF and the extended-range ensemble prediction method are reviewed and summarized.