Verification and Assessment of "23·7" Severe Rainstorm Numerical Prediction in North China

Zhang Bo; Zhang Fanghua; Li Xiaolan; Hu Yi

doi:10.11898/1001-7313.20240102

Vol.35, NO.1, 2024

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Zhang Bo, Zhang FangHua, Li XiaoLan, et al. Verification and assessment of '23·7' severe rainstorm numerical prediction in North China. J Appl Meteor Sci, 2024, 35(1): 17-32. DOI: 10.11898/1001-7313.20240102.

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Zhang Bo, Zhang FangHua, Li XiaoLan, et al. Verification and assessment of "23·7" severe rainstorm numerical prediction in North China. J Appl Meteor Sci, 2024, 35(1): 17-32. DOI: 10.11898/1001-7313.20240102.

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Verification and Assessment of "23·7" Severe Rainstorm Numerical Prediction in North China

DOI: 10.11898/1001-7313.20240102

Zhang Bo^{1, 2},
Zhang Fanghua^{1, 2
,
,},
Li Xiaolan^{1, 2},
Hu Yi^{1, 2}

1.
National Meteorological Center, Beijing 100081
2.
China Meteorological Administration Hydro-meteorology Key Laboratory, Beijing 100081

Received Date: 2023-11-13
Rev Recd Date: 2023-12-13
Publish Date: 2024-01-31

Abstract

Abstract

During the severe rainstorm in North China from 31 July to 1 August in 2023, CMA-GFS, CMA-EPS, EC-EPS, EC-HR, NCEP-GFS, CMA-TYM, CMA-MESO, and CMA-BJ are tested and evaluated using synoptic verification, threat score (TS), and MODE (method for object-based diagnostic evaluatin). The persistence and intensity of long-term heavy rainfall, as well as the area and intensity of short-term heavy rainfall, are tested and analyzed for their effectiveness over time. Results indicate that the cumulative precipitation predicted by EC-EPS may exceed 100 mm for 14 days in advance, but there is no prediction ability for extreme heavy precipitation above 600 mm. EC-HR forecast for the location of precipitation is generally accurate up to 8 days in advance. In the short term, the daily precipitation intensity forecast by CMA-BJ closely matches the actual situation, indicating its significance in predicting precipitation extremes. The average and maximum precipitation values of CMA-GFS, EC-HR, and NCEP-GFS in the areas with concentrated heavy precipitation are lower than actual values. CMA-GFS doesn't perform very well while EC-HR is closer to the actual situation. CMA-GFS, EC-HR, and NCEP-GFS models all provide inadequate forecasts for the persistence of heavy rainfall. However, EC-HR has a relative advantage in predicting persistent precipitation 8 days in advance. TS of CMA-BJ is highest for precipitation forecasts above 50 mm and 100 mm. EC-HR and CMA-TYM precipitation forecasts above 50 mm are relatively stable. From the daily MODE results of the precipitation concentration period from 29 July to 31 July, it is evident that EC-HR exhibits a northward predictive characteristic, while the prediction of CMA-BJ is slightly southward. The forecasting ability of CMA-GFS is insufficient, and forecasts from NCEP-GFS and CMA-MESO are not stable. The high-pressure system in North China has a significant impact on the precipitation. EC-HR model forecasts the formation and reinforcement of a 500 hPa high-pressure system 3 to 4 days earlier than CMA-GFS and NCEP-GFS models. It also surpasses both in predicting the precise location and strength of intense precipitation. Additionally, EC-HR model predicts the emergence of a 925 hPa low-pressure trough and a low-level jet 7 days in advance. However, it underestimates the intensity of the trough and jet system, with the actual location being to the west to north. CMA-GFS and NCEP-GFS underestimate the impact of the Taihang Mountains on easterly winds, leading to significantly lower precipitation forecasts. The analysis of the deviation in the 36 h precipitation forecast for 30 July also shows that EC-HR has weak predictions for low-level wind fields, trough positions, and convective precipitation, resulting in a weak intensity of heavy precipitation and a west-north precipitation area.
- North China severe rainstorm;
- numerical model;
- synoptic verification;
- verification;
- TS;
- MODE

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References(33)

Figures and Tables

图 1 2023年7月29日—8月1日累积降水量实况(单位：mm)

Fig. 1 Observed accumulated rainfall from 29 Jul to 1 Aug in 2023(unit:mm)

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图 2 2023年7月29日—8月1日500 hPa高度场(等值线，单位：dagpm)、850 hPa风场(风羽)和风速(填色)

Fig. 2 500 hPa height(the red contour, unit:dagpm), wind vector(the barb) and wind velocity(the shaded) at 850 hPa from 29 Jul to 1 Aug in 2023

DownLoad: Full-Size Img PowerPoint

图 3 EC-EPS对2023年7月29日08:00—8月2日08:00累积降水量不低于100 mm的概率预报检验(· 代表实况累积降水量不低于100 mm的格点)

Fig. 3 Probability prediction verification of accumulated rainfall no less than 100 mm in EC-EPS from 0800 BT 29 Jul to 0800 BT 2 Aug in 2023(· denotes grid point with observed accumulated rainfall no less than 100 mm)

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图 4 2023年7月29日08:00—8月2日08:00预报的累积降水量(右上角数值为模式预报最大降水量)

Fig. 4 Predicted accumulated rainfall from 0800 BT 29 Jul to 0800 BT 2 Aug in 2023(the number in the upper right corner denotes the maximum predicted rainfall)

DownLoad: Full-Size Img PowerPoint

图 5 模式提前36 h预报的2023年7月29—31日的日降水量

Fig. 5 Predicted daily rainfall for 36 h forecast by models from 29 Jul to 31 Jul in 2023

DownLoad: Full-Size Img PowerPoint

图 6 模式36 h时效预报的2023年7月29—31日日降水量不低于50 mm降水个体经向和纬向位移偏差

Fig. 6 Meridional and zonal displacement deviations of daily rainfall no less than 50 mm for 36 h forecast by models from 29 Jul to 31 Jul in 2023

DownLoad: Full-Size Img PowerPoint

图 7 2023年7月29—31日关键区(35°~41°N，113°~118°E)36 h时效的日降水量预报检验

Fig. 7 Verification of daily rainfall for 36 h forecast in key region(35°-41°N,113°-118°E) from 29 to 31 in Jul 2023

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图 8 2023年7月29—31日20:00平均500 hPa位势高度预报场(蓝色等值线，单位：dagpm)

(红色等值线为588 dagpm等值线实况)

Fig. 8 Mean of predicted 500 hPa height at 2000 BT from 29 Jul to 31 Jul in 2023(the blue contour, unit:dagpm)

(the red contour denotes observed 588 dagpm)

DownLoad: Full-Size Img PowerPoint

图 9 EC-HR 2023年7月29日20:00起报的30日20:00 850 hPa和925 hPa风场预报场(蓝色风羽)与分析场(黑色风羽)对比(阴影为地形高度)

Fig. 9 Comparison of 850 hPa, 925 hPa predicted wind(the blue barb)at 2000 BT 30 Jul 2023 initiated at 2000 BT 29 Jul 2023 and analysis field(the black barb)(the shaded denotes elevation)

DownLoad: Full-Size Img PowerPoint

References

[1]	Li Z, Chen J, Ma Z S, et al. Deviation distribution features of CMA-GFS cloud prediction. J Appl Meteor Sci, 2022, 33(5): 527-540. doi: 10.11898/1001-7313.20220502
[2]	Huangfu X G. The verification for ensemble prediction system of National Meteorological Center. J Appl Meteor Sci, 2002, 13(1): 29-36. http://qikan.camscma.cn/article/id/20020103
[3]	Wang Y, Gong Y, Chen F J, et al. Comparison of two verification methods for 6 h precipitation forecasts of regional models. J Appl Meteor Sci, 2013, 24(2): 171-178. http://qikan.camscma.cn/article/id/20130205
[4]	Liu Y J, Huang Q Q, Zhang H B, et al. Refined assessment of wind environment over Winter Olympic competition zone based on large eddy simulation. J Appl Meteor Sci, 2022, 33(2): 129-141. doi: 10.11898/1001-7313.20220201
[5]	Zhang S T, Zhong J Q, Lu B, et al. Performance evaluation of CMA-BJ V2. 0 system for precipitation forecast in North China. J Appl Meteor Sci, 2023, 34(2): 129-141. doi: 10.11898/1001-7313.20230201
[6]	Li J, Du J, Xu J Y, et al. The assessment and verification of high-resolution ensemble forecast for a heavy rainstorm. Torrential Rain Disasters, 2020, 39(2): 176-184.
[7]	Pan L J, Xue C F, Zhang H F, et al. Comparative analysis on precipitation forecasting capabilities of two ensemble prediction systems around Qinling Area. J Appl Meteor Sci, 2016, 27(6): 676-687. doi: 10.11898/1001-7313.20160604
[8]	Huang L P, Deng L T, Wang R C, et al. Key technologies of CMA-MESO and application to operational forecast. J Appl Meteor Sci, 2022, 33(6): 641-654. doi: 10.11898/1001-7313.20220601
[9]	Moore P G. Statistical theory and methodology in science and engineering. J R Stat Soc Ser A Stat Soc, 1961, 124(4): 573-574. doi: 10.2307/2342937
[10]	Zhang Y, Luo Y L, Guan Z Y. Temperature, relative humidity, and cloud fraction predicted by the NCEP global forecast system at the ARM SGP site during 2001-2008:Comparison with ARM observations. Chinese J Atmos Sci, 2012, 36(1): 170-184.
[11]	Pan L J, Zhang H F, Zhu W J, et al. Forecast performance verification of the ECMWF model over the Northeast Hemisphere. Clim Environ Res, 2013, 18(1): 111-123.
[12]	Dai J H, Mao M, Shao L L, et al. Applications of a new verification method for severe convection forecasting and nowcasting in Shanghai. Adv Meteor Sci Tech, 2013, 3(3): 40-45.
[13]	Hoffman R N, Liu Z, Louis J F, et al. Distortion representation of forecast errors. Mon Wea Rev, 1995, 123(9): 2758-2770. doi: 10.1175/1520-0493(1995)123<2758:DROFE>2.0.CO;2
[14]	Pan L J, Zhang H F, Wang J P. Progress on verification methods of numerical weather prediction. Adv Earth Sci, 2014, 29(3): 327-335.
[15]	Qu Q N, Sheng C Y, Fan S D, et al. Comparison of the multi-model forecasts for severe precipitation based on the object verification. Meteor Mon, 2019, 45(7): 908-919.
[16]	You F C, Wang G R, Guo R, et al. The application analysis of MODE method to the rainfall forecast test. Meteor Mon, 2011, 37(12): 1498-1503.
[17]	Zhang B, Zhao B, Niu R Y, et al. The performance verification of several numerical models in middle range forecasting of regional heavy rainfall in North China. Torrential Rain Disasters, 2017, 36(2): 118-124.
[18]	Su X, Kang Z M, Zhuang X R, et al. Uncertainty analysis of heavy rain belt forecast during the 2020 Meiyu period. Meteor Mon, 2021, 47(11): 1336-1346.
[19]	Dong L Q. Verification of quantitative forecasts for storm rainfall during the period of Changjiang-Huaihe Mei-yu in 1991. J Appl Meteor Sci, 1993, 4(3): 333-340. http://qikan.camscma.cn/article/id/19930357
[20]	Ebert E E, McBride J L. Verification of precipitation in weather systems: Determination of systematic errors. J Hydrol, 2000, 239(1/2/3/4): 179-202.
[21]	Fu J L, Dai K. The ECMWF model precipitation systematic error in the east of southwest China based on the contiguous rain area method for spatial forecast verification. Meteor Mon, 2016, 42(12): 1456-1464.
[22]	Chang Y, Wen J W, Yang X F, et al. Verification of rainstorm based on numerical model about CMA-TYM and SCMOC in Nenjiang Basin. J Appl Meteor Sci, 2023, 34(2): 154-165. doi: 10.11898/1001-7313.20230203
[23]	Wang X M, Li H. Spatial verification evaluation of typhoon rainstorm by multiple numerical models. Meteor Mon, 2020, 46(6): 753-764.
[24]	Chyi D, He L F, Wang X M, et al. Fine observation characteristics and thermodynamic mechanisms of extreme heavy rainfall in Henan on 20 July 2021. J Appl Meteor Sci, 2022, 33(1): 1-15. doi: 10.11898/1001-7313.20220101
[25]	Li Z C, Chen Y, Wang X M, et al. Thinking of extreme rainstorms from the August 1975 event to the July 2021 event. Meteor Environ Sci, 2022, 45(2): 1-13.
[26]	Li H, Wang X M, Zhu F. Comprehensive evaluations of multi-model forecast performance for "21·7" Henan extreme rainstorm. Trans Atmos Sci, 2022, 45(4): 573-590.
[27]	Cai X N, Zong Z P, Ma J, et al. Analysis of Meiyu characteristics and performance verification of the medium-range forecasting models in 2020. Torrential Rain Disasters, 2020, 39(6): 629-636.
[28]	Lu C L, Li H J, Song L M, et al. Analysis of forecast error in a continuous heavy rain event during the spring-like plum rain season. Meteor Mon, 2018, 44(1): 132-141.
[29]	Fu J L, Chen S, Shen X L, et al. Comparative study of the cause of rainfall and its forecast biases of two cold vortex rainfall events in North China. Meteor Mon, 2019, 45(5): 606-620.
[30]	Huo Z H, Li X L, Chen J, et al. CMA global ensemble prediction using singular vectors from background field. J Appl Meteor Sci, 2022, 33(6): 655-667. doi: 10.11898/1001-7313.20220602
[31]	Cao Y, Zhao L N, Gong Y F, et al. Evaluation and error analysis of precipitation forecast capability of the ECMWF high-resolution model. Torrential Rain Disasters, 2019, 38(3): 249-258.
[32]	Zhang F H, Yang S N, Hu Y, et al, Water vapor characteristics of "23·7" torrential rainstorm event in North China. Meteor Mon, 2023, 49(12): 1421-1434.
[33]	Yang S N, Zhang F H, Hu Y, et al. Analysis on the characteristics and causes of the "23·7" torrential rainfall event in North China. Torrential Rain and Disaster, 2023, 42(5): 508-520.