2021年四川省2 m温度数值模式预报检验评估

Verification of Numerical-Model Performance for 2m Temperature in Sichuan Province in 2021

通过对比分析3个区域数值模式(CMA-MESO-3KM、SW3KM和SW9KM)2021年3—12月逐日2 m温度(包括日最高温和最低温)预报结果和气象观测站实况数据,检验评估了3个数值模式对四川省2 m温度的预报性能。结果表明:(1)模式对最低温度预报效果好于最高温度,SW3KM模式对3—10月2 m温度预报略好于SW9KM和CMA-MESO-3KM模式,SW3KM模式对最高、最低温预报效果优于SW9KM模式,其准确率最多可分别提高13.4%、31.9%,较CMA-MESO-3KM模式最多都可提高18.8%。(2)温度误差分布有明显的日变化特征,3个模式预报温度误差从凌晨至上午逐渐减小,而下午至晚上逐渐增大,SW3KM和SW9KM模式预报温度上午较实况偏高,其它预报时段较实况偏低,CMA-MESO-3KM模式预报温度较实况偏低。(3)温度预报准确率与海拔高度密切相关,预报准确率随着海拔高度增加而降低,系统性偏差增大。(4)CMA-MESO-3KM模式冷季温度预报偏高、暖季预报偏低,12时起报略好于00时;SW3KM和SW9KM模式00时起报的20℃以上温度预报偏低、20℃以下温度预报偏高,而12时起报的低于30℃附近温度预报较实况偏低,但00时起报温度误差小于12时起报。

Through the comparative analysis of the forecast results of the regional numerical models(CMA-MESO-3KM,SW3KM,SW9KM)and the actual data of meteorological observation stations of daily 2m temperature(including daily maximum temperature and minimum temperature)from March to December 2021,the forecast performance of these three numerical models for 2 m temperature in Sichuan Province was tested and evaluated.The results showed that:(1)The model forecasts for the minimum temperature were better than those of the maximum temperature.SW3KM model was slightly better than the SW9KM and CMA-MESO-3KM models in predicting 2 m temperature from March to October,the highest and lowest temperature accuracy rates of SW3KM model were higher than those of SW9KM model,up to 13.4%and 31.9%respectively,and up to 18.8%higher than that of CMA-MESO-3KM model.(2)The errors of temperature forecast showed daily variation.The error of the three models gradually decreased from early morning to morning and gradually increased from afternoon to evening,the morning temperatures of the SW3KM and SW9KM models were higher than the observation,the temperature in other forecast periods are lower than the observation,and the forecasting temperatures of CMA-MESO-3KM model were lower than the real situation.(3)The temperature accuracy was closely related to the altitude,the forecast accuracy decreased with the the increase of altitude,and the systematic deviation increased.(4)The CMA-MESO-3KM model had a higher temperature forecast in the cold season and a lower forecast in the warm season,and the forecast from 12:00 p.m.was slightly better than that from 00:00 a.m..The temperature forecast of SW3KM and SW9KM models above 20°C startiing at 00:00 a.m.was lower than the real situation,and the temperatures forecast below 20°C was higher than the real situation,while the temperature forecast below 30°C starting at 12:00 p.m.was lower than the real situation,but the temperature error starting at 00:00 a.m.was less than 12:00 p.m.