precipitation trend meaning in English

降水趋势

And the minimum tbb fluctuation matches well to the precipitation trend ( the lower tbb the heavier rainfall )
强降水还与对流有关，降水强度总体上跟t _ ( bb )强度成正相关， t _ ( bb )越低降水越强。
Hourly rainfall information derived from weather radars and raingauges is routinely ingested into the model for more effective simulation of rain systems fig . 4 , allowing forecasters to make useful reference of the quantitative precipitation forecasts and precipitation trends provided by objective model guidance
运作后，天气雷达及雨量计的每小时雨量分析数据定规地被放到模式内图表4 ，让模式更有效地模拟降雨系统的演变，为预报员提供极具参考价值的定量降雨预报和降雨趋势的客观指引。