WEATHER PHENOMENA IN TENERIFE 1

Weather Phenomena in Tenerife 1 is the first article in a series of six that cover specific weather phenomena in Tenerife and, by extension, the Canary Islands.

Island of Eternal Spring … Where have we heard that before? Long ago, this was an expression that Christopher Columbus uttered when he stayed in the region. He did not stay long enough to experience that this subtropical area can sometimes go through meteorological dips.

Over 300 days of sunshine and temperatures to die for. Many Europeans envy this climate, and that is why so many northerners flock to the subtropical archipelago, with Tenerife being the largest island. However, the weather here can be unpredictable, and not just in April. The showers don’t all fall in March either.

If you’re not here, it might not seem like much. Yet the weather gods occasionally play with phenomena that can only occur near the 28th degree north latitude. To list and describe all the exceptional weather phenomena, this article might well turn into a double trilogy because much can be said about the weather here.

There Are No Predictions

There are quite a few misconceptions when it comes to weather, especially when we talk about the weather for the coming days. One misunderstanding is that weather reports are not predictions, but rather expectations. The weather can indeed turn out differently than previously indicated. The terms “weather expectation” and “weather prediction” are often used interchangeably, and many people think that what is “expected” will also come true.

Meteorological institutes also look backward: they evaluate afterward how accurate the expectations were. We will publish several more articles that follow up on this Weather Phenomena in Tenerife (1).

Reliability

For temperature predictions, about 85% of the expectations are accurate, meaning that the observed temperature differs by less than two degrees from the forecasted temperature. Cloud cover and precipitation are the hardest to “predict.” As the forecast looks further into the future, the reliability decreases. Weather forecasts for five or six days ahead are generally less reliable than those for the first three days. That’s why on Aemet, the first few days are displayed in larger boxes (more credible), while the following three days are in smaller boxes because these predictions are less reliable.

But that’s not a weather phenomenon—that’s a misconception.

The real phenomena have names like mar de fondo, calima, cumulus lenticularis, alisios, and many more. To remove errors and legends and to clarify the truth of things, this explanatory column is published. Perhaps I won’t have to hear the phrase “sand blows over during a calima” anymore.

Mar de Fondo

What regularly occurs here and can be especially spectacular on the northern coasts is mar de fondo or groundswell in English. In Dutch, the term wind waves is also used. Wave heights of up to 5 meters or more are not uncommon when these destructive walls of water crash onto the Canary coasts.

When wind blows over water, short ripples form due to the instability of the current. These short ripples generate longer waves that grow further under the influence of the wind. This process develops in the open sea and grows with distance, eventually forming long and high waves.

Wind Generates Waves

When the waves become too steep, they break. At a given wind speed, a maximum wave height is reached. This is only achieved at a wind speed of 10 m/s and after the waves have traveled hundreds of kilometers under the influence of the wind. This groundswell is a wind-generated wave pattern on the ocean’s surface. It is a dangerous situation, and swimming is strongly discouraged. These waves are deadly! They come out of nowhere—every 10 to 15 minutes, a few heavy hits, and then it’s over again for a while.

It could happen to anyone. Tenerife lies in the middle of a giant ocean, what can you expect…

This article, Weather Phenomena in Tenerife (1), will be continued. All weather phenomena in Tenerife and the Canary Islands will be described separately in six different articles.

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Weather phenomena in Tenerife 1 ©