The forecast skill of Radar-basedextrapolation model MTREC (Multi-scale Tracking and Forecasting Radar Echoes) which is developed by the state key laboratory of severe weather (LaSW) of Chinese academy of meteorological science (CAMS). The forecast skill of MTREC and a meso-scale numerical weather prediction(NWP) BJ-RUC(WRF-based rapid updating cycling forecast system of Beijing meteorological bureau) were analyzed, base on thefour precipitation events observed by radar networks in Beijing in the summer of 2011. The results show that: (1) In terms of bias, both MTREC and BJ-RUC show overforecast the rain area.The bias of MTREC is stable for the considered four events, while the bias of BJ-RUC is sensitive to rainfall types. (2) In terms of the position of precipitation forecast, the forecast skill of MTREC depends on the scale of rainstorm. Larger scale rainstorm corresponds to higher forecast skill. BJ-RUC performs steadily except thelocal rainstorm event 3. (3) For 0~6 h precipitation forecast, MTREC has more skill than BJ-RUC for the first lead times. There is a cross-over point in time where BJ-RUC starts to have more skill than MTREC. The time of the cross-over point depends on the rainfall types. The larger the rainstorm scale is the later the cross-over point occurs. The results would provide some references to improve short-term quantitative precipitation based on blending MTREC and BJ-RUC.
[1]Rinehar R E, Garvey E T. Three-dimensional storm motion detection by conventional weather Radar[J].Nature, 1978, 273: 287-289.
[2]Li L, Schmid W, Joss J. Nowcasting of motion and growth of precipitation with radar over a complex orography[J]. J Appl Meteor, 1995, 34: 1286-1300.
[3]张亚萍, 陈明虎, 夏文梅, 等. 天气雷达回波运动场估测及在降水临近预报中的应用[J].气象学报, 2006, 64(5): 631-646.
[4]王改利, 刘黎平, 阮征, 等. 基于雷达回波拼图资料的风暴识别、 跟踪及临近预报技术[J]. 高原气象, 2011, 30(6): 1546-1555.
[5]胡胜, 汪瑛, 陈荣, 等. "雨燕"中风暴算法在北京奥运天气预报示范项目中的应用和改进[J]. 高原气象, 2009, 28(6): 1434-1442.
[6]俞小鼎, 王迎春, 陈明轩, 等. 新一代天气雷达与强对流天气预警[J]. 高原气象, 2005, 24(3): 456-463.
[7]王改利, 赵翠光, 刘黎平, 等. 雷达回波外推预报的误差分析[J]. 高原气象, 2013, 32(3): 874-883, doi: 10.7522/j.issn.1000-0534.2012.00081.
[8]Austin G L, Bellon A, Dionne P, et al. On the interaction between radar and satellite image nowcasting systems and mesoscale numerical models[R]. Proceedings Symposium on Mesoscale Analysis and Forecasting.Vancouver, ESA SP-282, 1987: 225-228, doi: 10.7522/j.issn.1000-0531.2012.00081.
[9]Golding B W. Nimrod: A system for generating automated very short range forecasts[J]. Meteor Appl, 1998, 5(1): 1-16.
[10]Lin C, Vasic S, Zawadzki I, et al. Precipitation forecast based on numerical weather prediction models and radar nowcasts[C]. Proceedings of ERAD, 2004: 201-205.
[11]胡胜, 罗聪, 黄晓梅, 等. 基于雷达外推和中尺度数值模式的定量降水预报的对比分析[J]. 气象, 2012, 38(3): 274-280.
[12]Wong W K, Linus H Y, Yeung Y C, et al. Towards the Blending of NWP with Nowcast-Operation Experience in B08FDP[C]. WMO Symposium on Nowcasting, Whistler, B.C. Canada, 30 Aug - 4 Sep 2009.
[13]Atencia A, Rigo T, Sairouni A, et al. Improving QPF by blending techniques at the Meteorological Service of Catalonia[J]. Nat hazarda Earth Syst Sci, 2010, 10(7): 1443-1455.
[14]Wang G L, Wong W K, Liu L P. Application of multi-scale tracking radar echoes scheme in quantitative precipitation nowcasting[J]. Adv Atmos Sci, 2013, 30(2): 448-460.
[15]陈敏, 范水勇, 楚艳丽, 等. 全球定位系统的可降水量资料在北京地区快速更新循环系统中的同化试验[J]. 气象学报, 2010, 68(4): 450-463.
[16]陈敏, 范水勇, 郑祚芳, 等. 基于BJ-RUC系统的临近探空及其对强对流发生潜势预报的指示性能初探[J]. 气象学报, 2011, 69(1): 181-194.
[17]范水勇, 陈敏, 郑祚芳, 等. 北京地区高分辨率快速循环同化预报系统性能检验和评估[J]. 暴雨灾害, 2009, 28(2): 119-125.
[18]Liang Qiaoqian, Feng Yerong, Deng Wenjian, et al. A composite approach of radar echo extrapolation based on TREC vectors in combination with model-predicted winds[J]. Adv Atmos Sci, 2010, 27(5): 1119-1130.
[19]Lai E S T. TREC application in tropical cyclone observation[R]. ESCAP/WMO Typhoon Committee Annual Review, 1998: 135-139.
[20]Germann U, Zawadzki I. Scale-dependence of the predictability of precipitation from continental radar images. Part I: Description of the methodology[J]. Mon Wea Rev, 2002, 130: 2859-2873.
[21]Reich S. An explicit and conservative remapping strategy for semi-Lagrangian advection[J]. Atmos Sci Lett, 2007, 8(2): 58-63.
[22]王红艳, 刘黎平, 王改利, 等. 多普勒天气雷达三维数字组网系统开发及应用[J]. 应用气象学报, 2009, 20(2): 214-224.
[23]伍静.刘黎平, 尤卫红, 等. 应用雷达拼图数据估测降水试验[J]. 气象科技, 2010, 38(2): 175-182.
[24]Zahraei A, Hsu K, Sorooshian S, et al. Quantitative precipitation nowcasting: A Lagrangian pixel-based approach[J]. J Atmos Res, 2012, 118: 418-434, doi: 10.1016/ j.atmosres.2012.07.001
[25]Davis C A, Brown B G, Bullock R G. Object-based verification of precipitation forecasts, Part I: Methodology and application to mesoscale rain areas[J]. Mon Wea Rev, 2006, 134: 1772-1784.
[26]Brown B G, Bullock R, Halley G J, et al. Application of the MODE object-based verification tool for the evaluation of model precipitation fields[C]. AMS 22<sup>nd</sup> Conference on Weather Analysis and Forecasting and 18<sup>th</sup> Conference on Numerical Weather Prediction, Park City, Utah, American Meteorological Society (Boston), 25-29 June 2007.
[27]Davis C A, Brown B G, Randy B, et al. The method for Object-based Diagnostic Evaluation (MODE) applied to numerical forecasts from the 2005 NSSL/SPC spring program[J]. Wea Forecasting, 2009, 24: 1252-1267.
