When the eye of a major hurricane makes landfall, residents in the region affected by the storm's center experience a temporary return to calm. Typically, the winds and rains subside, the sky clears up, and if it's already dark, the moon rises or the stars become visible.
Why does this happen? Keep reading because in this article we are going to tell you Why is there calm in the eye of the hurricane?.
Calm in the eye of the storm
With Hurricane Dorian in the Bahamas, after hours of strong winds, massive waves, and heavy rains, many residents of the Abaco and Grand Bahama islands felt as though Dorian was moving away. Images began circulating on social media, showing people leaving their homes to document the devastation wrought by the hurricane. The situation reached a critical point, prompting the U.S. National Hurricane Center (NHC) to use its social media platforms and official bulletins to urge caution and advise amateur photographers to seek shelter.
In fact, Just a few hours later, the rain and wind returned with an intensity greater than anything they had encountered up to that point. For more than 24 hours, heavy rains persisted in the Bahamas, and reports from both media and authorities indicated that the resulting devastation was significant.
How can we explain the calm that many people felt for several hours before the storm re-emerged? This phenomenon is known as the eye of the hurricane.
Why is there calm in the eye of the hurricane?
To understand the tranquility found at the heart of hurricanes, one must first understand the fundamental structure of these storm systems. Hurricanes develop in areas of low atmospheric pressure over warm waters, where vigorous air currents begin to circulate. As the ocean water warms, rising air generates eddies to offset the resulting low pressure. This phenomenon causes air to be drawn inward and upward, thus increasing the low pressure at the center.
You can learn more about the formation of the eye of the hurricane on our dedicated page..
When the wind speed reaches 128 km/h, a phenomenon is formed that meteorologists call "eye", which is characterized by its almost circular shape, creating a kind of "vacuum". This area is usually calm, and the reasons for this tranquility are remarkable.
The precise mechanism responsible for the formation of the core remains a matter of debate and is open to multiple theoretical interpretations. To provide a familiar example, consider a clothes dryer: as it spins, a vacuum forms at its center. A comparable phenomenon occurs in hurricanes, where multiple forces, such as centrifugal forces, contribute to the creation of a clear zone in the center.
In the eye, the presence of high temperatures and warm air causes the rapid upward movement of evaporated water, resulting in dry air that lacks the ability to condense and therefore typically does not produce clouds.
Is there a method to determine the location of the eye of the hurricane?
Today, the availability of satellite and radar technology allows for continuous monitoring of the eye of hurricanes. Reconnaissance aircraft often penetrate these systems to collect data, as their pressure serves as the primary indicator of increasing intensity. However, certain indicators can help identify their presence in the eye of a hurricane, provided the aircraft has the necessary measuring equipment.
In that region, there is a sudden decrease in atmospheric pressure. The temperature is often up to 10°C higher than the surrounding environment.. Here you can find additional information on hurricane-related concepts..
In the absence of instruments to assess these variables, it is important to note that conditions after a cyclone pass do not improve quickly. If a sudden calm occurs, you are likely to find yourself in the eye of the storm.
What is the logic behind the observation that the eye is often replaced by stronger rain and wind?
The well-known calm found at the center of hurricanes has inspired titles in a wide range of media, including literature and music. The explanation for why the eye is often replaced by the most severe part of the storm lies in the principles of physics.
To illustrate this point, look at the direction in which water swirls as it exits the shower or sink. Under optimal physical conditions, where no external forces or significant environmental factors interfere, it can be observed that in the In the northern hemisphere, rotation occurs constantly counterclockwise, while in the southern hemisphere, rotation is observed clockwise. The phenomenon responsible for this was identified in the 19th century and is known as the Coriolis effect, which arises from the rotation of the Earth on its axis.
The force responsible for the counterclockwise rotation of hurricanes in the Northern Hemisphere is significant. According to NOAA, this phenomenon explains why the greatest intensity of winds is concentrated on the right side, a result of the Coriolis effect, which plays a crucial role in the formation of wind eddies in that region. You can learn more about the differences between hurricanes and tornadoes here..
According to NOAA, "A stationary hurricane with sustained winds of 145 km/h will produce winds reaching up to 160 km/h on its right side.". Furthermore, "the eye of the storm moves at a speed of 130 km/h on the right side and maintains the same speed of 130 km/h on the left side if it starts to move in any direction. However, there is an additional factor that triggers the appearance of heavy rains and winds after the eye passes.
The defining characteristic of hurricanes is that their centers are marked by a formation of storm clouds. These formations, called cumulonimbus clouds, have significant vertical development and pose considerable challenges for pilots. The structure of these clouds forms the eyewall, where the strongest winds within the tropical cyclone are concentrated. Therefore, meteorologists often recommend seeking shelter during its passage, as the surrounding wall of storms can quickly re-emerge, marking the beginning of a new phase of the storm.
