RUI: Precipitation Regimes Associated with Inverted Troughs

小行星9610356 人们发现，与倒槽相关的气旋和锋面系统在美国中部经常发生。 一项为期6年的调查显示，在美国中部落基山脉背风面和密西西比河之间，有247例涉及倒槽。这种相对频繁的现象在当前的极锋模型中没有考虑。 这个项目的目标是建立在先前的研究，通过确定在倒槽的情况下，降水分布的动态支持。 的 对倒槽情况的初步调查已经确定，在涉及倒槽的情况下，有两种主要的降水分布：1）大部分降水福尔斯落在较老的、改变的极地气团中的槽的下游（Ahead情况）和2）大部分降水福尔斯落在北极新鲜空气供应中的槽的上游（Behind情况）。 在为期6年的倒槽调查中，42%的情况属于“超前”类别，只有9%属于“落后”类别，但其中几个“落后”案例是大暴雪。 其余案件是两类案件的组合。 这个项目将涉及合成的超前和落后的情况下，比较强制机制。 将对每种复合物进行暖平流、锋生和准地转强迫等抬升机制的计算，以确定这两类过程的相对重要性，并对两种降水信号进行比较。 希望这个项目的结果将提供一个概念模型，供预报员在真实的时间内使用，以改善倒槽情况下的雨雪预报。 ***

9610356 Weisman Cyclones and frontal systems associated with inverted troughs have been found to be a frequent occurrence in the Central United States. A 6-year survey has shown 247 cases involving inverted troughs in the Central U.S. between the lee of the Rockies and the Mississippi River. This relatively frequent phenomenon is not accounted for in current polar front models. The goal of this project is to build upon prior research by determining the dynamic support for the precipitation distribution during inverted trough cases. The preliminary survey of inverted trough cases has determined that there are two primary precipitation distributions in cases involving an inverted trough: 1) most of the precipitation falls downstream of the trough in the older, modified polar air mass (Ahead cases) and 2) most of the precipitation falls upstream of the trough in the fresh supply of arctic air (Behind cases). In the 6-year survey of inverted troughs, 42% of the cases fell into the Ahead category, while only 9% fell into the Behind category, but several of the Behind cases were major blizzards. The remaining cases were a combination of the two categories. This project will involve compositing the Ahead and Behind cases for comparison of forcing mechanisms. Calculations of lifting mechanisms such as warm advection, frontogenesis, and quasi-geostrophic forcing will be performed for each composite in order to identify the relative importance of these processes in the two categories and to enable comparisons between the two precipitation signals. It is hoped that the results of this project will provide a conceptual model for forecasters to use in real time to improve rain and snow forecasting during inverted trough cases. ***