Autumn is the highlight of the hurricane season, also known as the Cape Verde season, after the islands where the so-called “hurricane highway” is emerging. Here are seven facts about this great – and sometimes fatal – weather phenomenon.
1. The Hurricane Highway begins near the African coast.
The Hurricane Highway begins on the Cape Verde Islands off the northwest coast of Africa. Thunderstorms that are expected to become hurricanes often form a tropical depression near the islands, which slowly organizes and intensifies the following week as the system moves towards the Caribbean. These storms have a long time to get together, but they also have to travel a long distance without losing their strength to reach the east coast as a hurricane. Some storms can thrive with little wind shear, plenty of warm water, and humid air, while others starve and disperse when they encounter cooler water and strong winds, or take in dry, dusty air from the Sahara.
2. The Hurricane Highway emerges from an eastern jet stream.
3. The largest hurricanes begin with the smallest storms on the Hurricane Highway.
Hurricanes, hurricanes, typhoons – all of these are names for the same force of nature as Hurricane Andrew, which hit the east coast in 1992. Hurricanes like Andrew don’t just form from the air. All tropical cyclones require a relatively small “core” of thunderstorms to develop. When the air and water temperatures are right, these thunderstorms sometimes turn into a violent low-pressure system that can do great damage. We see many of these seedling thunderstorms over the ocean every year, but only a small number of them become hurricanes.
4. Hurricanes form in different places in different months.
Where a tropical storm or hurricane begins its journey across the ocean depends on what time of year it is. Storms that form at the beginning of the season usually start with thunderstorms or cold fronts that remain very close to the land above the water. Almost all of the storms that form in the Atlantic in June are brought to life within a few hundred miles of land. However, when we reach the peak of the hurricane season, they begin to form in the ocean – to the coast of Africa.
5. Fall is the highlight of the hurricane season on the hurricane highway.
The hurricane season in the Atlantic lasts from June 1st to November 30th. Storms are most common in this six-month section of the year, but can sometimes form sooner or later. However, the period between mid-August and mid-October is typically the climatological highlight of the season. This is because as the ocean water heats up, the atmosphere becomes conducive to violent storms and increases the risk of hurricanes and tropical storms.
6. Cape Verde hurricanes can easily end up in the record books.
Tropical waves that migrate west from the African coast in the middle of summer are to blame for some of the worst hurricanes we have seen in the United States. For example, on August 8, 2005, a small tropical wave appeared off the coast of Africa, which soon became Tropical Depression 10. This depression would fall apart a few days later, but its remains moved toward the United States and developed into a new tropical depression over the Bahamas on August 23. This new tropical depression became Hurricane Katrina, the most expensive hurricane that has ever hit the United States.
It’s a similar story for many – but not all – major hurricanes in recent history. Hurricanes Andrew, Dennis, Ivan, Isabel and Ike were all Cape Verde storms that came to life thousands of miles from where they would ultimately wreak havoc.
7. Strong hurricanes can form elsewhere in autumn.
While the Far Eastern part of the Atlantic Ocean is a stronghold of activity at this time of year, this isn’t the only place to watch if you live near the coast. Storms that form near the country can quickly turn into a disaster. Hurricane Sandy formed south of Jamaica and hit New Jersey in a few days in 2012. A tropical depression that developed east of Florida on September 18, 2005 exploded into Hurricane Rita just three days later with 180 mph wind – The most intense storm ever recorded in the Gulf of Mexico.
Meteorologists are currently forecasting an above-average hurricane season in 2020. It might be worth preparing for it: NOAA suggests collecting some important disaster stocks, undertaking an insurance investigation, and finding the safest level.