I was driving back to graduate school in Los Angeles through the Midwest after a summer spent at the Kellogg Biological Field Station in Michigan. One of my pit stops was in Omaha, Nebraska where I was amazed at the lightening show that lit up the sky from what seemed like almost everywhere. The experience was a huge contrast to my relatively lightning free experience living in Los Angeles. The local climate, geography, and the stabilizing influence of the cold Pacific Ocean waters, mean that thunder and lightning are pretty infrequent in the area.
Lightning, a powerful natural atmospheric electrical discharge, is significantly influenced by the geographical and climatic conditions of an area. The United States, with its diverse geography, experiences a wide variation in lightning activity. Lightning typically arises when certain conditions align: a layer of warm, moist air close to the Earth’s surface, overlaid by cooler, drier air higher up, and a mechanism to elevate the warmer air upwards.
A recent study, published in the Bulletin of the American Meteorological Society, takes a look at where in the lower 48 U.S. states is lightning is the most prevalent. Led by Chris Vagasky, a meteorologist with the University of Wisconsin-Madison, data from the U.S. National Lightning Detection Network (NLDN) between 2017 and 2022 was mapped out and analyzed. The authors of the study found that, on average, the United States experiences 23.4 million lightning flashes, 55.5 million strokes, and 36.8 million ground strike points annually.
Where lightning strikes the most in the United States
These lightning strikes are not distributed evenly over the contiguous United States. The study found that the highest concentration of cloud to ground lightning strikes in the U.S. is found near the Gulf Coast and Southern Plains, covering areas like Florida, southern Louisiana, Mississippi, and parts of Texas, Oklahoma, and Kansas.
While the Midwest certainly put on quite a light show during my travels home, the study found that Florida had the highest overall density of lightning strikes. In 2023, the Miami-Fort Lauderdale area experienced over 120,000 lightning strikes.
Overall, Florida’s density of lightning strikes was 112.6 strikes per square kilometer. The state with the second highest density of lightening strikes was Mississippi with 104 strikes per square kilometer.
The Gulf Coast’s frequent lightning strikes are attributed to its warm, moist air from the Gulf of Mexico and sea breezes caused by the temperature difference between land and sea. These factors, along with the region’s mostly flat topography, which occasionally aids in air uplift, create perfect conditions for thunderstorm development, leading to a high incidence of lightning.
Where lightning strikes the least in the United States
The climatic influence of the Pacific Ocean and its cool waters means that the Western United States along the coast experiences the lowest amount of lightning strikes.
References
Vagasky, C., Holle, R. L., Murphy, M. J., Cramer, J. A., Said, R. K., Guthrie, M., & Hietanen, J. (2024). How Much Lightning Actually Strikes the United States?. Bulletin of the American Meteorological Society. https://doi.org/10.1175/BAMS-D-22-0241.1
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Fonte : National Geographic
