A five‐year radar climatology of convective precipitation for New Jersey

Abstract

A radar climatology of convective precipitation for New Jersey during the summer season (May-September) was developed using manually digitized radar (MDR) data from four local radar sites. Convective precipitation frequencies were determined by tabulating occurrences of echo intensity levels equal to 2 or more for each of 63 grid boxes located in and around New Jersey. Convective precipitation frequencies over a 5-year period (1978-1982) were plotted by grid box, and isopleths of duration and intensity level were constructed. The distribution of the frequency of occurrence of convective activity was examined for thunderstorm (level 3 or more) occurrence and severe thunderstorm (level 5 or more) occurrence. The highest convective frequencies occurred over south-eastern Pennsylvania while the greatest frequency of more intense convection occurred over south-central New Jersey. An analysis of variance (ANOVA) was performed on the data set to determine the relative variability of convective precipitation in the grid. Year-to-year and week-to-week variability was high whilst intergrid-box variability was low. Duncan's multiple range test (DMRT) was applied to compare individual years to each other, and individual weeks to each other. When grid boxes were assigned to four climatological regions and DMRT applied, some regions were found to be significantly different from one another. No significant differences were found between grid boxes within each region. There was no interaction between grid regions and years as differences in mean convective activity between regions remained generally constant from year to year. The distribution of convective activity over New Jersey was found to be determined by local climatological factors while the total frequency from year to year was determined by the mean synoptic pattern.

Derivation of a 10-Year Radar-Based Climatology of Rainfall

“…This percentage is larger for, respectively, the 24-h radar (17%) and rain gauge (22%) depths. Earlier studies that show the spatial distribution of rainfall frequencies are Croft and Shulman (1989) and Baeck and Smith (1995).…”

“…Some other studies utilizing long-term radar datasets are Croft and Shulman (1989), Baeck and Smith (1995), Joss and Lee (1995), Young et al (2000), Vignal and Krajewski (2001), Borga et al (2002), Nzeukou et al (2006), and Xie et al (2006). Nelson et al (2003) constructed a 5-yr dataset of hourly rainfall accumulations for the Mississippi River basin.…”

An object-based climatology of precipitation systems in Sydney, Australia

“…However, this time frame is long enough to conduct climatological studies. Previous researchers have employed these datasets to study the climatology of precipitation systems over specific regions such as the United States (Ghebreyesus and Sharif 2020; Kuo and Orville 1973;Croft and Shulman 1989;Falconer 1984;Cintineo et al 2012;Murillo et al 2021), Europe (Kaltenboeck and Steinheimer 2015;Kreklow et al 2020;Weckwerth et al 2011;Overeem et al 2009;Bližňák et al 2018;Fairman Jr et al 2015;(Junghänel et al 2016;Nisi et al 2016;Fluck et al 2021;Lukach et al 2017;Saltikoff et al 2010), Asia and Australia (Chen et al 2012;Warren et al 2020;Dowdy et al 2020). A limitation of the previous radar-based studies is that they often employed a pixel-based statistical approach which limits the storm properties to rainfall/hail frequency and intensity as a function of position.…”

An Object-based Climatology of Precipitation Systems in Sydney, Australia

“…However, this time frame is long enough to conduct climatological studies. Previous researchers have employed these datasets to study the climatology of precipitation systems over specific regions such as the United States (Ghebreyesus and Sharif 2020;Kuo and Orville 1973;Croft and Shulman 1989;Falconer 1984), Europe (Kaltenboeck and Steinheimer 2015;Kreklow et al 2020;Weckwerth et al 2011;Overeem et al 2009;Bližňák et al 2018;Fairman Jr et al 2015) and Asia (Chen et al 2012).…”