全球动力模式对大气季内低频振荡，特别副热带地区降水和温度季内变率的模拟性能普遍较差。而传统统计预报模式的滤波方法存在数据边界问题，无法直接用于实时业务预报。提前10-30天的介于常规天气预报（小于10天）与短期气候预测（大于30天）之间的延伸期预报一直是气象部门的预报业务“空白”。

近年来，我院青年教师朱志伟、气候动力研究中心李天明教授、徐邦琪教授利用“非传统滤波”方法（Hsu et al. 2014, CD; Zhu et al. 2015, CD），提取预报因子和预报量的时空耦合信息，建立了时空投影的统计延伸期预报模型（Spatial Temporal Projection Model, STPM）。利用稳定的前期季内预报因子，分别建立了中国夏季降水（Zhu and Li, 2017, CD）、冬季温度与极端冷事件（Zhu and Li, 2017, QJRMS）、夏季温度及热浪（Zhu and Li, 2018, CD）等统计延伸期预报模型，取得良好的预报效果。这些工作是中国大陆范围统计延伸期预报的首次尝试。目前，他们研制的延伸期预报模型被广泛推广，实时预报产品已在国家气候中心网页滚动发布（http://cmdp.ncc-cma.net/pred/cn_s2s.php?Elem=Pr）。

The flowchart of the STPM. X and Y are normalized predictor and predictand fields respectively. i1, j1 (i2, j2) denote spatial grids for predictand (predictor) field, t is temporal grid during a training period, and n1 (n2) indicates succeeding (preceding) n1 (n2) pentads to time t. K is total number of SVD modes. Uk and Vk denote the singular vectors of predictor and predictand respectively. m denotes the mth SVD mode that passes the 99 % confidence level in the cross validation. M is the total number of the modes that pass the 99 % confidence level. uk and vk indicate the time series of expansion coefficient of the kth SVD mode for the predictor and predictand. Solid arrows denote the training procedures during the model development. Forecast procedures at time tp are denoted by dashed arrows.

相关文章：

Zhu, Z., T. Li, 2018: Extended-range forecasting of Chinese summer surface air temperature and heat waves. Clim. Dyn., 50(5-6), 2007-2021. doi: 10.1007/s00382-017-3733-7.

Zhu, Z., T. Li, 2017: Statistical extended-range forecast of winter surface air temperature and extremely cold days over China. Q. J. R. Meteor. Soc., 704(143), 1528-1538. doi: 10.1002/qj.3023.

Zhu, Z., T. Li, 2017: The statistical extended-range (10–30-day) forecast of summer rainfall anomalies over the entire China. Clim. Dyn., 48(1), 209-224. doi: 10.1007/s00382-016-3070-2.

Zhu, Z., T. Li, P.-C. Hsu, J. He, 2015: A spatial-temporal projection model for extended-range forecast in the tropics. Clim. Dyn., 45(3), 1085-1098. doi: 10.1007/s00382-014-2353-8.

Hsu P.-C., T. Li, L. You, J. Gao, and H.L. Ren, 2015: A spatial-temporal projection model for 10-30 day rainfall forecast in South China. Clim. Dyn., 44, 1227-1244. doi: 10.1007/s00382-014-2215-4