Collaborative Research: Observations and Modeling of Mesoscale Precipitation Banding in Cool-season Storms

要改进对流层外气旋内降水的预报，就需要继续综合观测和模式，以了解与降水带有关的演变和过程。美国东北部气旋逗号头部内的中尺度条带已被记录为导致局部强降水率和数量。在中层锋生和稳定度降低的情况下，逗点头部内的主带的生命周期和微物理已经被记录下来，但对多带风暴的研究较少。潜在的假设是，与冬季风暴相关的许多定量降水预报（QPF）错误是由于模型预测这些多波段的困难，因为它们的空间尺度较小，对流特征较多，这个研究小组将把模拟和观测研究结合起来，以了解美国东北部的热带气旋内的降水特征谱。States.使用来自WSR-88 Ds的约20年的雷达数据，主要机场的几年终端多普勒天气雷达（TDWR），高空探测，来自垂直指向雷达的观测，一个disdrometer，以及位于纽约长岛斯托尼布鲁克的多角度雪花相机（MASC），以及高分辨率网格分析和天气研究与预报（WRF）预测，以表征带状降水和冰微物理学，并评估模式输出。其目标是表征带生命周期和气旋周围的细胞和带的轨迹，并量化的重要性，风暴降水积累的多带状结构相对于其他降水功能。我们还将确定需要什么样的参数集来真实地模拟多条带降水。我们的工作将解决冰微物理参数化和带状降水的中尺度可预测性使用合奏的历史运行和灵敏度study.Intellectual优点：在QPF的改进在凉爽的季节继续落后于我们的能力，预测的压力和位势高度场内的冬季风暴。该奖项将通过使用基于特征的跟踪算法完成美国东北部地区带和细胞的起源，生长和衰减的综合气候学，提高对中纬度气旋逗号头内降水特征谱的理解。到目前为止，也没有使用真实的情况下，集中在一个中纬度气旋周围的多波段的成因和演变的模拟研究，和微物理验证在所有尺度的带一直是有限的。这项工作将提供一个更好的了解带状降水，这可以适用于其他地区的带内的逗号头。我们的地面微物理工作将评估和改进我们新的微物理参数化，重点是提高模型内的riming表示。更广泛的影响：美国东北部的主要冬季风暴具有广泛的社会和经济影响。纽约市大都会区是近2000万人的家园，是沿着东海岸的主要交通枢纽。该地区近年来遭受了几次大风暴的袭击（http：//www.nyc.gov/html/oem/html/hazards/winter_history.shtml）。该项目的结果将有助于改进预报员用于预测逗号头部内带状降水的现有概念模型，并改进中尺度模型内的QPF。Colle博士和Yuter博士每年将分别资助一名研究生。一些本科生研究助理也将接受培训，做数据处理和分析。他们的研究结果将由学生在研究研讨会上作为海报展示，如每年春季和夏季由NCSU和斯托尼布鲁克举行的研讨会。研究结果还将在会议报告和期刊文章中传播。此外，Yuter博士计划在当地的北卡罗来纳州科学博物馆为普通观众做一些关于雪和冬季风暴的演讲。

Improved forecasting of precipitation within extratropical cyclones requires continued integration of observations and models to understand the evolution and processes associated with precipitation bands. Mesoscale banding within the comma-head portion of Northeast U.S. cyclones has been documented to cause localized intense precipitation rates and amounts. The life cycle and microphysics of the primary band within the comma head in the presence of mid-level frontogenesis and reduced stability has been documented, but there has been less attention investigating storms with multiple bands. The underlying hypothesis is that many of the quantitative precipitation forecast (QPF) errors associated with winter storms are the result of difficulties in models predicting these multi-bands given their smaller spatial scales, more convective characteristics, and their upscale growth to a single band.This team will integrate modeling and observational study to understand the spectrum of precipitation features within extratropical cyclones over the Northeast United States. Use ~20 years of radar data from the WSR-88Ds, several years of Terminal Doppler Weather Radar (TDWR) at the major airports, upper air soundings, observations from a vertically pointing radar, a disdrometer, and Multi-Angle Snowflake Camera (MASC) at Stony Brook, NY on Long Island, as well as high resolution gridded analyses and Weather Research and Forecasting (WRF) predictions to characterize banded precipitation and ice microphysics and to evaluate model output. The goal is to characterize band lifecycle and tracks of cells and bands around the cyclone and to quantify the importance to storm precipitation accumulation of multi-banded structures relative to other precipitation features. We will also identify what set of parameters are needed to realistically model multi-banded precipitation. Our work will address the parameterization of ice microphysics and mesoscale predictability of banded precipitation using an ensemble of historical runs and sensitivity studies.Intellectual Merit:Improvement in QPF during the cool season continues to lag our ability to predict the pressure and geopotential height fields within winter storms. This award will improve the understanding of the spectrum of precipitation features within the comma head of a mid-latitude cyclone by completing a comprehensive climatology of the genesis, growth, and decay of bands and cells over the Northeast U.S. region using an feature-based tracking algorithm. To date, there have also been no modeling studies using real cases focusing on the multi-band genesis and evolution around a mid-latitude cyclone, and the microphysical verification within all scales of bands has been limited. This work will provide an improved understanding of banded precipitation, which can be applied to other regions with bands within the comma head. Our ground-based microphysical work will evaluate and improve our new microphysics parameterization focusing on improving riming representation within models.Broader Impacts:Major winter storms in the northeast U.S. have wide ranging societal and economic impacts. The New York City Metropolitan Area is the home to nearly 20 million people and is a major transportation hub along the East coast. This area has been hit by several major storms in recent years (http://www.nyc.gov/html/oem/html/hazards/winter_history.shtml). The results from this project will help improve existing conceptual models used by forecasters to anticipate banded precipitation within the comma head as well as to improve the QPFs within mesoscale models. Dr. Colle and Dr. Yuter will each support one graduate student per year under this award. Several undergraduate research assistants will also be trained to do data processing and analysis. Their results will be presented by the students as posters at research symposia such as the ones held by NCSU and Stony Brook each spring and summer. Results will also be disseminated in conference presentations and journal articles. Additionally, Dr. Yuter plans to present a few general audience talks about snow and winter storms at local North Carolina science museum.