基于风暴相对螺旋度的降雨预报模型检验

摘要

Storm relative helicity is an index which could measure the strength of the physical development of convective storms, so it has practical significance for the strong convective weather forecasting. By extracting Doppler weather radar wind data of 153 cases in Tianjin during 2008-2010 to calculate the storm relative helicity, combined with the storm information extracted from the radar reflectivity factor graph, we could give references for forecasting storm rainfall based on storm relative helicity. The results show that the accuracy of rainfall prediction model proposed in this study reached 61%, of which forecast rainfall 2 hours in advance accounted for 41%, and those in less than two hours 59%. As a conclusion, combined with other rainfall characteristics, the storm relative helicity has an good effect on storm rainfall forecast.%风暴相对螺旋度是一个衡量对流风暴发展强度的物理量，所以对强对流天气的预报具有实际意义。通过提取2008—2010年3 a天津地区153个降雨过程的多普勒天气雷达风场数据来计算风暴相对螺旋度，然后将风暴相对螺旋度与从雷达反射率因子图中提取的风暴信息相融合，得到基于风暴相对螺旋度的降雨预报模型。经过2014年4—8月天津地区59个降雨过程对本文所提出的降雨预报模型进行验证，结果表明降雨预报模型的准确率达到61%，其中提前2 h预测降雨占41%，在2 h以内预测降雨占59%。上述结果说明，风暴相对螺旋度在结合其他降雨特征后对降雨具有良好的预报效果。