A hurricane is a severe storm with high-speed winds that forms over warm waters in tropical or subtropical areas. Hurricanes have sustained winds of at least 74 miles per hour, and an area of low air pressure in the centre called the eye. On average, Hurricanes are 340 miles in diameter. Hurricane winds blow in a counterclockwise spiral around the calm, but roughly circular centre called the eye. The eye is the warmest part of the storm.

Surrounding the eye is the eyewall, a wall of thunderclouds. The eyewall has the most rain and the strongest winds of the storm, gusting up to 225 miles per hour in severe hurricanes. The smaller the eye, the stronger the winds. If you are facing in the direction that the hurricane is travelling, the right side generally has the fastest winds, and the left side usually has the most rain. Air Pressure is the weight of the column of air that extends from the ground (or water’s surface) to the top of the atmosphere. The air pressure is very low in a hurricane. The scientific name for a hurricane is a tropical cyclone. 

Colorado State University researchers predicting 
slightly below-average activity for 2023 Atlantic Hurricane Season

The CSU team will issue forecast updates on June 1, July 6 and August 3, 2023.

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Hurricanes develop over warm tropical waters. The energy necessary for its development comes from the warm ocean waters over which it passes. To form and develop, hurricanes must be supplied with a constant supply of warm, humid air and this air only exists over oceans with a temperature greater than 80 degrees Fahrenheit. Further, for a hurricane to form this warm surface water must exist in a layer that is at least 600 feet deep.

Through the process of evaporation, energy stored in the ocean is lifted into the storm and then released during condensation. Hurricanes are actually powered by the (latent) heat energy released from condensation. The warmer the water surface over which a tropical wind system passes, the more energy is available for the storm.

Initially a hurricane begins as a group of unorganized thunderstorms. To develop into a hurricane, significant cyclonic circulation must occur around the disturbances. This circulation provides additional moisture and (latent) heat energy and this in turn enhances and intensifies the development of the thunderstorms. The thunderstorms also begin to organise themselves into spiral bands that swirl cyclonically towards the centre of the storm.

Hurricanes are formed when damp air rises from the surface of warm tropical seas. The sun heats the air and, as the air rises, there is a powerful updraft. This cools and turns into rain. The updraft is kept fuelled as more hot moist air rises. The movement of the earth in an eastwardly direction pushes the moist air currents to one side resulting in hurricanes moving in a counter-clockwise direction.

The damage that hurricanes inflict is usually caused by high winds, heavy rainfall, storm surge, and tornadoes.

High winds cause damage by blowing down objects, creating choppy waves and high seas which can inundate coastal areas with seawater. Wind speed in a hurricane is usually directly related to atmospheric pressure. The lower the pressure the faster the winds blow.

Rainfall within a hurricane can exceed 24 inches in a 24-hour period and if this rainfall occurs on land, flooding often occurs.

Storm surge is an increase in the height of the ocean’s surface. It occurs when low atmospheric pressure causes the ocean surface to expand, and because the hurricanes cyclonic winds blow water towards the eye. Some hurricanes have produced storm surge of more than 24 feet.

Tornadoes are known to occur in about 25 percent of the hurricanes that make landfall and they can cause a considerable amount of damage. Some scientists also suspect that the thunderstorms that occur near the eye of a hurricane can produce very strong downbursts (vertical downward movements of air).

A potential hurricane goes through four basic phases before it attains hurricane strength. The four stages are: Tropical disturbance, tropical depression, tropical storm, and full-fledged tropical cyclone or Hurricane.

Tropical Disturbance

When the water vapour from the warm ocean condenses to form clouds, it releases its heat to the air. The warmed air rises and is pulled into the column of clouds. Evaporation and condensation continue, building the cloud columns higher and larger. A pattern develops, with the wind circulating around a centre (like water going down a drain). As the moving column of air encounters more clouds, it becomes a cluster of thunderstorm clouds, called a tropical disturbance.

Tropical Depression

As the thunderstorm grows higher and larger, the air at the top of the cloud column is cooling and becoming unstable. As the heat energy is released from the cooling water vapour, the air at the top of the clouds becomes warmer, making the air pressure higher and causing winds to move outward away from the high pressure area. This movement and warming causes pressures at the surface to drop. Then air at the surface moves toward the lower pressure area, rises, and creates more thunderstorms. Winds in the storm cloud column spin faster and faster, whipping around in a circular motion. When the winds reach between 25 and 38 mph, the storm is called a tropical depression.

Tropical Storm

When the wind speeds reach 39 mph, the tropical depression becomes a tropical storm. This is also when the storm gets a name. The winds blow faster and begin twisting and turning around the eye, or calm centre, of the storm. Wind direction is counter clockwise (west to east) in the northern hemisphere and clockwise (east to west) in the southern hemisphere. This phenomenon is known as the Coriolis effect.

Hurricane

When the wind speeds reach 74 mph, the storm is officially a hurricane. The system is now mature and the eye is well defined. Mature hurricanes usually develop a cloud free eye at their centre. In the eye, air is descending creating clear blue skies. The eye of the hurricane maybe 12 to 31 miles in diameter. Surrounding the eye are bands of organised thunderstorm clouds and the strongest winds and heaviest precipitation are found in the area next to the eye. The trade winds (which blow from east to west) push the hurricane toward the west—toward the Caribbean, the Gulf of Mexico, or the south eastern coast of the U.S. The winds and the low air pressure also cause a huge mound of ocean water to pile up near the eye of the hurricane, which can cause monster storm surges when all this water reaches land. If atmospheric conditions are right, it can strengthen.

Know your Hurricane Risk

Hurricanes are not just a coastal problem. Find out how rain, wind, water could happen where you live so you can start preparing now.

Make an Emergency Plan

Make sure everyone in your household knows and understands your hurricane plan. Discuss the latest how your family guidance on Coronavirus (COVID-19) and how it may affect your hurricane planning. Don’t forget a plan for the office, kids’ daycare, and anywhere you frequent.

Gather Supplies

Have enough supplies for your household, include medication, disinfectant supplies, cloth face coverings, pet supplies in your go-bag or car trunk.

Those with Disabilities

If you or anyone in your household is an individual with a disability identify if you may need additional help during an emergency.

Know your Evacuation Zone

You may have to evacuate quickly due to a hurricane. Learn your evacuation routes, practice with household, and identify where you will stay.

Recognize Warnings and Alerts

Have several ways to receive alerts. Download the DDME ALERT App for iPhone users click: https://apple.co/3N37KhC  for Android users: https://bit.ly/3N027AH 

Add both DDME’s Duty Phones numbers to your contacts [PLS: 1-649-243-3363] and [GDT: 1-649-244-3363]. Send both numbers a message to sign up to receive Whats App alerts via the link: https://forms.gle/tT6c21ZY6ntKEePZ6

• Step 1 - Save both DDME Phone Contacts
  • DDME PLS Duty Mobile Phone: (649) 243-3363
  • DDME GDT Duty Mobile Phone: (649) 244-3363
• Step 2 - Complete the Contacts Information Form https://forms.gle/tT6c21ZY6ntKEePZ6
• Step 3 - Send a message ‘FORM Completed. ADD ME for UPDATES’ via What’s App to both duty phone numbers

Only individuals who have saved these numbers to their phone's address book will receive DDME’s Emergency broadcast messages.

Review Important Documents

Make sure your insurance policies and personal documents like ID are up to date. Make copies and keep them in a secure password-protected digital space.

Strengthen your Home

Declutter drains and gutters, bring in outside furniture, consider hurricane shutters.

Get Tech Ready

Keep your cell phone charged when you know a hurricane is in the forecast and purchase backup charging devices to power electronics.

Help your Neighborhood

Check with neighbours, senior adults, or those who may need additional help securing hurricane plans to see how you can be of assistance to others.

Prepare your Business

Make sure your business has a continuity plan to continue operating when disaster strikes.