Yesterday I started taking a look at lightning data for 2019 versus 2020. This was motivated by an article in the Washington Post that reported that Vaisala had noted a 23 percent decrease in total lightning activity across the US from 2019 to 2020. The year-to-year drop in lightning activity is the largest the company has noted in its 31 years of record keeping.
These two figures compare total lightning density counts for 2019 (above) versus 2020 (below). The biggest decreases appear to have occurred over east Texas, from Kansas eastward to the central Mississippi Valley, and across much of the western third of the US.
The changes in CG flash density (above versus below) seem somewhat similar; however, since Vaisala produced these maps using different color scales, they are quite hard to compare directly.
Comparing annual precipitation for the states is quite interesting (2019 above and 2020 below). The entire northern half of the country was much drier during 2020 than it was in 2019. The southern Plains were drier, and the Southwest was extremely dry (as we well know here in Arizona). The total lightning density plots shown in first four maps above, also reflect the extreme dry conditions in the West - particularly from much of Arizona northward across the entire Great Basin Region and into the Northwest.
Of interest are the the very wet conditions across the Southeast in 2020, where there appears to be little change in the annual total density plots. I find this quite puzzling, and don't have any hypotheses for this strange disconnect between the annual lightning and the annual precipitation.
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