Hurricane Information

Tropical Cyclone is a generic term referring to a storm that forms in tropical regions that is essentially a “warm-core” storm without fronts or other weather features associated with it. In the Central Pacific there are three types of tropical cyclones, each defined by their associated wind speeds.

Tropical Depression

Winds up to 38 mph and designated by a number

Tropical Storm

Winds of 39 to 73 mph and designated by a name

Hurricane

Winds equal to or greater than 74 mph and designated by a name. Hurricanes are broken down further into five categories of increasing wind threat with category 5 being the strongest.

On average 4 to 5 tropical cyclones form in or travel through the Central Pacific ocean during the calendar year. Records indicate that one-third of these cyclones reach hurricane strength, one-third reach only tropical storm strength, and the final one-third only reach tropical depression strength.

Since 1970 tropical cyclones have impacted the Central Pacific each month of the year, excluding February and May. The peak time of occurrence is July through October, with the most common occurrence during August.
Hawaii is certainly not immune to direct impacts from tropical cyclones. Hawaii has had four hurricane landfalls since 1950.

In Hawaii, mountainous terrain accelerates hurricane and tropical storm winds causing extremely high winds that can destroy buildings, structures, trees, vegetation and crops.

Heavy and prolonged rains can accompany all types of tropical cyclones including hurricanes, tropical storms, and tropical depressions. Even the weakest tropical depressions can bring torrential rains and flash flooding to the Hawaiian Islands.

When forming a disaster preparedness plan, consider each factor and how it could affect your family and property.

Hurricane Watch

A  hurricane watch lets you know that weather conditions are favorable for a hazard to occur. It literally means "be on guard!" During a weather watch, gather awareness of the specific threat and prepare for action - monitor the weather to find out if severe weather conditions have deteriorated and discuss your protective action plans with your family.

Hurricane Warning

A hurricane warning requires immediate action. This means a weather hazard is imminent - it is either occurring or it is about to occur at any moment. During a weather warning, it is important to take action: grab the emergency kit you have prepared in advance and head to safety immediately. Both watches and warnings are important, but warnings are more urgent.