A 10‐year spatial climatology of squall line storms across Oklahoma

Abstract

ABSTRACT:Severe thunderstorms are an important and relatively common component of the annual weather across the State of Oklahoma. Such weather brings hazardous features such as, large hail, damaging winds, and tornadoes, while also providing beneficial precipitation vital to the state's agricultural and hydrological needs. In any given year, severe weather activity is dictated by seasonal and monthly changes in atmospheric conditions, which frequently determine the type and severity of subsequent storms.This study focuses on a 10-year period between 1994 and 2003 to quantify the spatial and temporal characteristics of severe squall line storms across Oklahoma. A squall line is a linearly organized set of storms that has a sharp radar reflectivity gradient at its leading edge typically followed by a less intense stratiform region. Squall line storms are one of the most significant storm modes observed in Oklahoma due to their large aerial extent, long durations, high winds, heavy rains, and hail. For this study, geographic information systems (GIS) were used to store geo-referenced storm data and spatially analyse storm events across varying timescales. The analysis revealed that squall lines were most predominant across eastern Oklahoma with a decreasing westward gradient. The annual averaged storm track was from the west to east, while the monthly mean squall line tracks were oriented from southwest to northeast from January through April, from west to east during May, from northwest to southeast from June through September, and from southwest to northeast through the end of the year. In addition, high-resolution analyses of squall line initiation and termination locations revealed important geographical variability in typical storm lifecycle.

Life Cycle Characteristics of Warm-Season Severe Thunderstorms in Central United States from 2010 to 2014

“…Tucker and Li [21] pointed out that thunderstorms had a longer lifespan in summer than in spring in central United States. In our study area, the average duration in summer (June to August) is 23.2 min, while the average duration in spring months (April and May) is 22.7 min, which verifies that long lived thunderstorms do favor summer months though long lived thunderstorms account for only a small portion of total thunderstorms (Figure 6a The histogram of thunderstorm durations (Figure 6a) shows an exponential decay distribution consistent with Hocker and Basara [4]. The average duration of the thunderstorms is 23.1 min, and 65.8% of the thunderstorms have a duration between 5 and 20 min.…”

“…The histogram of thunderstorm durations (Figure 6a) shows an exponential decay distribution consistent with Hocker and Basara [4]. The average duration of the thunderstorms is 23.1 min, and 65.8% of the thunderstorms have a duration between 5 and 20 min.…”

“…Weather monitoring systems, such as the Doppler radar, collect data with increasing spatial and temporal resolutions and provide great opportunities for researchers to study convective weather events [3,4]. For example, a number of researchers have studied the life cycle characteristics of mesoscale convective systems (MCS) using meteorological satellite products.…”

Characteristics of warm season precipitating storms in the Arkansas–Red River basin

“…One of the challenges of this data set is its vast size and the need to process it in a timely fashion. Hocker and Basara [2007, 2008] recently studied squall lines and supercell storms using Geographic Information Systems (GIS). They were concerned with the numbers and spatial distribution of the storms rather than storm precipitation and relied almost exclusively on raw radar reflectivity data.…”

Mesoscale observations of an extended heat burst and associated wind storm in Central Oklahoma

“…Typically, mesoscale windstorm events in Oklahoma are associated with severe squall lines (Hocker and Basara, 2008b) or nonlinear MCS events termed 'derechos' (Johns and Hirt, 1987;Coniglio et al, 2004). In each of these cases, heavy precipitation is a primary mechanism for the generation of strong to severe surface winds.…”