Posted on May 09 2017
Lightning can, and does, strike in the same place—not only twice, but many, many times. Of course, it helps if that place is the tip of a skyscraper in the Midwest. Tall, especially metallic objects, will provide the shortest and most attractive path for a charged cloud to let loose its abundance of electrical energy. Electrical and broadcast towers are other likely targets, and the repeat strikes can number in the double digits for even one storm. There’s no surprise there, given the prominence of those objects, but how likely are more random locations to experience lightning? Those who track such things find that in areas that have an of average number of thunderstorms, such as some of our northeastern states, any particular quarter-acre of land might expect to see a lightning strike once in a hundred years. Where storm frequency is greater, the chances rise. That’s an average, and just like a coin flip, lightning could repeat its performance ten minutes after its first arrival, if conditions are right. So lightning can do as it likes, but by and large, it’s not something that comes around to the same spot with regularity.
ANNUAL NUMBER OF DAYS WITH THUNDERSTORMS
If you want to speak in a broader sense, you could ask where does lightning put on a general show most frequently? Overall, tropical Africa has the greatest number of strong lighting-producing locales, especially in the Lake Victoria area. Folks in the Midwestern U.S. or Florida get generous helpings of such sky shows quite regularly, especially at certain times of the year. This is due to weather patterns that cause the collision of warm, moist subtropical air with cooler northern air masses. This type of condition exists in various places around the planet, but for intensity and reliability, the apparent King of Lightning Venues is in northern South America, in the country of Venezuela.
Venezuela’s far northwestern corner features what is considered either the largest lake on the continent, or a very large inlet of the Caribbean Sea, a water body known as Lake Maracaibo. The lake is nearly 150 miles long from its southern shore to the Gulf of Venezuela on the Caribbean, and about 75 miles across at its widest point. Though it is constricted at its northern end as it reaches the gulf, enough tidal mixing occurs that the water in the northern half of the lake is brackish. The southwestern shores of the lake are a vast wetlands, and the greater Maracaibo Basin is defined by mountains on three sides, which are the northernmost reaches of the Andes. It is a combination of wind and weather patterns influenced by these mountains that create an unusual phenomenon over the lake and wetlands, fed by the Rio Catatumbo. In a directional reverse to the situation in the middle of the U.S., warm, wet air sitting in the north meets cooler air (in this case coming off the mountains), and thunderstorms develop. Highly charged clouds then deliver lightning in copious amounts over the lake. Bolts rain down or jump cloud to cloud at a rate of roughly once per second, adding up to perhaps as many as 40,000 strikes a night. These hours-long lightning shows are no different from other intense displays in other regions, but the unusual thing about the storms here is that they occur very frequently—on nearly 300 nights of the year. From about April through November, the night sky shines brightly. “Catatumbo lightning”—or El Relampago del Catatumbo, as the locals call it—has become a meteorological reference for persistent displays of lightning.
The reliability of this nighttime light show, sometimes called “Marcaibo’s Lighthouse”, has made it a navigational aid for ships many miles off the coast of Venezuela for centuries. Its light played a part in two different wartime events when it revealed a maritime sneak attack by Sir Francis Drake in the late 16th century, and provided visibility for Venezuelan forces facing the Spanish fleet during the Venezuelan War of Independence in 1823. Both confrontations ended to Venezuelan advantage thanks to the illumination of Catatumbo lightning, so it is a celebrated phenomenon and a source of national pride. Of course, all sorts of special and magical qualities have been ascribed to the display, both by native peoples who have watched it since time immemorial, and by more recent residents. Nothing impresses like a good lightning show. The local Wari people have legends of the light from huge gatherings of fireflies paying homage to the gods, and more modern arrivals make up their own stories for what seems inexplicable.
Amongst these unsupported notions are that Catatumbo lightning is said to come in colors; that it has qualities or origins unlike that found in other places; that swamp gases from the wetlands affect or actually cause the display; and that the lightning has no thunder to accompany its bolts. Meteorologists dispell all this, and report that there is nothing unusual about this Venezuelan display because it arises from the very same mechanisms of lightning anywhere. The amount of methane present in the local air is insufficient to change the atmospheric chemistry and enhance either conductivity or color. The appearance of color is ascribed to the fact that the bolts are being viewed from a fairly long distance. The atmospheric dust that is illuminated by the lightning gives the bolts a reddish or orangey quality, similar to sunset colors when the sun’s light is traversing a long path through the atmosphere. Distance also plays into the “silent thunder” effect. At distances of 15 miles or more, thunder is hard to hear, and most observers are far from the source. Lightning, by the laws of physics, can’t not make a racket, but you have to be closer to experience it. So in and of itself, Catatumbo lightning is nothing strange or mystical, but its sheer volume and regularity make it unlike the electrical storms of any other region.
The nighttime routine of the Catatumbo display is such a part of life there that in 2010, when the lightning show came to a halt, there was a great deal of concern. No one is certain why, but it likely had to do with the weather and water temperature changes accompanying an El Nino condition, including a drought in the region. The overcutting of Venezuelan rainforest may also have had a hand in intensifying weather conditions that led to the worrisome cessation, which reversed itself after four months. The show was back on, the tourists returned to see it, and since then, the night skies have flashed on schedule. The Venezuelans were much relieved, but it will be interesting to see how the inevitably growing changes in climate will affect El Relampago del Catatumbo in the future.
Planning a trip to go see Catatumbo Lightning? Check out this full-color wall map of Venezuela!
Header Image: Lightning over towns photo: Source: Wikimedia: Cesar sanchez007 (CC 3.0)
Lightning on lake photo: Source: Wikimedia: Thechemicalengineer (CC 3.0)