智能网格预报产品在大兴安岭暴雪天气中的释用分析

Interpretation and analysis of intelligent grid forecast products in blizzard weather in Daxing’anling

本文利用MICAPS4.1平台上的高空、地面、智能网格预报、集合预报等数值预报产品,对2018年10月26-28日发生在黑龙江省大兴安岭地区的一次区域性暴雪天气过程形成机制进行探讨。结果表明:高空槽后强冷空气与槽前西南暖湿气流在大兴安岭上空交汇,导致暖锋锋生,地面暖锋与低空暖式切变相互作用形成暴雪天气。暴雪的主要触发系统就是超极地冷空气促使高空槽强烈发展切涡,≥20m·s^-1的西南低空急流作为水汽输送带,为暴雪区提供了充足的水汽来源;垂直上升运动中心和散度辐合辐散中心耦合且加强,为暴雪提供了强有力的动力抬升条件,有利于上升运动的增强发展。智能网格预报产品对这次大兴安岭暴雪天气的落区、降水量级以及强降雪的时段,都预报的比较准确。

This paper uses the high-altitude, ground, intelligent grid forecasting, ensemble forecasting and other numerical forecasting products on the MICAPS4.1 platform to explore the formation mechanism of a regional blizzard weather process in the Daxinganling area of Heilongjiang Province from October 26-28, 2018. The results show that the strong cold air behind the trough intersects with the warm and wet air flow in the southwest of the trough over the Great Xing’an Mountains, leading to the frontogenesis of the warm front. The interaction between the surface warm front and the low-altitude warm shear forms a snowstorm weather. The main trigger system of the snowstorm is that the superpolar cold air promotes the strong development of shear vortices in the upper trough. The southwest low-level jet (≥20m·s^-1) serves as the water vapor conveyor belt, providing sufficient water vapor source for the snowstorm area. The coupling and strengthening of vertical ascending motion center and divergence convergence and diverence center provide strong dynamic lifting conditions for snowstorm, which is conducive to the enhancement and development of ascending motion. The intelligent grid forecasting products are more accurate in forecasting the falling area, precipitation level and heavy snowfall time of the Daxinganling blizzard weather.