16.3 BASELINE CLIMATOLOGY OF SOUNDING DERIVED PARAMETERS ASSOCIATED WITH DEEP, MOIST CONVECTION
16.3 BASELINE CLIMATOLOGY OF SOUNDING DERIVED PARAMETERS ASSOCIATED WITH DEEP, MOIST CONVECTION
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发表时间：
2002
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通讯作者：
J. Craven;H. Brooks;J. Hart
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作者：
J. Craven;H. Brooks;J. Hart
使用广泛的高空观测样本开发了一些用于预测深层对流的几种参数的基线气候。以前的气候通常包含有限数量的病例或不包括无效案例，这限制了其预测实用程序。评估了美国48个美国的三年夜晚（0000 UTC）Rawinsonde数据（约60,000个声音）。云到地面雷电数据和暴风雨数据的恶劣天气报告用于将声音分类为无雷声，通用雷声，严重，冰雹 /风或大量龙卷风的条件的代表。在详细的计算中，使用最不稳定的包裹与平均提升的100-HPA包裹之间的对流可用势能（CAPE）和提升的冷凝水平（LCL）之间的比较。检查了几个不同层的失误率，以确定使用静态稳定性与CAPE预测风暴严重程度的实用性。最后，研究了低级剪切，以区分严重和重要的龙卷风发作。主要发现之一是，与其他五个类别相比，大量龙卷风发作的矢量差异高于地面的0-1公里（AGL）的幅度差异。对于重大龙卷风事件和其他对流类别，LCL /平均升高的LCL（MLLCL）高度之间也有统计学上的显着差异。此外，与其余的数据集相比，对于0-1 km剪切，0-6 km剪切和MLLCL Heights AGL的季节性变化要少得多。
A baseline climatology of several parameters commonly used to forecast deep, moist convection is developed using an extensive sample of upper-air observations. Previous climatologies often contain a limited number of cases or do not include null cases, which limit their forecast utility. Three years of evening (0000 UTC) rawinsonde data (approximately 60,000 soundings) from the lower 48 United States are evaluated. Cloud-to-ground lightning data and severe weather reports from Storm Data are used to categorize soundings as representative of conditions for no thunder, general thunder, severe, significant hail / wind, or significant tornado. Among the detailed calculations are comparisons between both convective available potential energy (CAPE) and lifted condensation level (LCL) using a most unstable parcel versus a mean lifted 100-hPa parcel. Lapse rates for several different layers are inspected to determine the utility of using static stability versus CAPE to forecast storm severity. Lastly, low-level shear is studied in an attempt to distinguish between severe and significant tornado episodes. One of the major findings is a considerable difference between 0-1 km above ground level (AGL) magnitude of vector difference of wind for significant tornado episodes versus the other five categories. Statistically significant differences are also noted between LCL / mean lifted LCL (MLLCL) heights AGL for significant tornado events and the other convective categories. In addition, much less seasonal variation is found for 0-1 km shear, 0-6 km shear, and MLLCL heights AGL for significant tornado events compared with the remainder of the data set.