Marines


Hurricane and Typhoon

 

 

The terms hurricane and typhoon are regionally specific names for a strong tropical cyclone, a low-pressure system that originates in the tropics. These cyclones usually include intense thunderstorms and strong winds that can exceed 157 mph. Hurricanes/ typhoons and tropical storms can further result in tornadoes and heavy flooding. They can cause extensive damage through both strong winds and high flood waters from rain and storm surges. The Atlantic hurricane season lasts from June 1 to November 30, with the peak season from mid- August to late October. The Eastern Pacific hurricane season begins May 15 and ends November 30. A typhoon is a tropical cyclone in the Northwest Pacific Ocean west of the International Date Line with sustained winds of (or those that exceed) 74 mph. Typhoons can happen at any time of year, but the season typically runs from July 1 to September 30.

 

 

Hurricane Categories

  • Category 1—Winds 74–95 mph, 64-82 kt, 119-153 km/h, very dangerous winds will produce some damage.

  • Category 2—Winds 96–110 mph, 83-95 kt, 154-177 km/h, extremely dangerous winds will cause extensive damage.

  • Category 3—Winds 111–129 mph, 96-112 kt, 178-208 km/h, devastating damage will occur.

  • Category 4—Winds 130–156 mph, 113-136 kt, 209-251 km/h, catastrophic damage will occur, well-built framed homes can sustain severe damage with loss of most of roof structure and/or some exterior walls.

  • Category 5—Winds exceeding 157 mph, 137 kt, 252 km/h, catastrophic damage will occur, high percentage of framed homes will be destroyed with total roof failure and wall collapse.

*Category 3, 4, and 5 hurricanes are considered “major hurricanes.”
*In the western North Pacific, the term super typhoon is used for tropical cyclones with sustained winds exceeding 150 mph.

 


 

Hurricane Terminology

  • Tropical depression—A system of clouds and thunderstorms with a defined surface circulation and sustained winds that do not exceed 38 mph.

  • Tropical storm—A system of clouds and thunderstorms with a defined surface circulation and sustained winds 39-73 mph.

  • Hurricane/Typhoon—A system of clouds and thunderstorms with a defined surface circulation and sustained winds 74 mph or higher.

  • Storm surge—An abnormal rise of water pushed ashore by a storm, over and above the predicted astronomical tide. Storm surges, which are often the greatest threat to life and property, are affected by a number of complex factors and can vary in magnitude despite hurricane categories. For example, Hurricane Katrina, a category 3 hurricane, had a storm surge of 28 ft., while Hurricane Charley, a category 4 hurricane, had a storm surge of 6-8 ft.

  • Storm tide—A combination of storm surge with normal tide, increasing the amount of water (e.g., a 15-foot storm surge with a 2-foot normal tide creates a 17-foot storm tide).

  • Hurricane/tropical storm warning—Hurricane/tropical storm conditions are expected within 36 hours in specified areas.

  • Hurricane/tropical storm watch—Hurricane/tropical storm conditions are possible within 48 hours in specified areas. Stay tuned to radio or TV for further information.

  • Short-term watches and warnings—Provide detailed information about specific threats during hurricanes, such as flash flooding or tornadoes.

 


 

Prep Steps

  • Stay informed: Verify and update official contact information in the Marine Corps Enterprise Mass Notification System (eMNS) and register all cell phones, home phone, email addresses, etc. in eMNS.

  • Determine whether your property is in danger from tidal floods, storm surges, or dam failures, and take flood precautions.

  • Learn community evacuation routes and how to find higher ground.

  • Make a written family evacuation plan.

  • Make a written family communication plan in case you are separated. 

  • Make plans to secure your property:

  • Cover all of your home’s windows with permanent storm shutters, which offer the best protection for windows, or with 5/8” marine plywood, cut to fit and ready to install.

  • Install straps or additional clips to securely fasten your roof to the frame structure to reduce roof damage.

  • Trim trees and shrubs around your home so they are more wind resistant.

  • Clear loose and clogged rain gutters and downspouts.

  • Reinforce your garage doors to prevent dangerous and expensive structural damage.

  • Bring in all outdoor furniture, decorations, garbage cans, and anything else that is not tied down.

  • Build an emergency kit.

 


 

TCCOR Levels

Tropical Cyclone Conditions of Readiness (TCCOR) are the Marine Corps' guidelines for estimating how long a region has and the actions necessary before it will be hit by destructive winds. Destructive winds are defined as winds of 58 mph or greater. At each TCCOR level, installations and tenant commands have set actions or checklists to complete prior to the storms arrival.

  • TCCOR 5 - Indicates that we are in hurricane season. From June 1 to November 30, all vulnerable installations should maintain a minimum TCCOR 5 level (except Guam/Marianas - which maintains TCCOR 4 year round). This is not the absence of threat; it just indicates that any storm/hurricane is greater than 72 hours away.

  • TCCOR 4 - Trend indicates possible threats of destructive winds within 72 hours.

  • TCCOR 3 - Destructive winds of force are possible within 48 hours.

  • TCCOR 2 - Destructive winds of force are anticipated within 24 hours.

  • TCCOR 1 - Destructive winds of force are occurring or anticipated within 12 hours.

  • TCCOR-IC (Caution) - Destructive winds of 50 knots or greater are anticipated with in six hours.

  • TCCOR-IE (Emergency) - Destructive winds of 50 knots or greater are occurring.

  • TCCOR-SW (Storm Watch) - Destructive winds are no longer being experienced but winds are still gale force. 

  • TCCOR-R (Recovery) - Winds are below 34 knots and the CO has ordered recovery operations to commence.

 


 

Actions to Take

  • Avoid using the phone, except for serious emergencies.

  • Stay tuned to radio, TV, and eMNS alerts for more information and further instructions.

  • Create a supply of water for sanitary and household purposes by filling bathtub and large containers.

  • Turn your refrigerator to the coldest setting and keep the door closed. 

  • Turn off propane tanks, and utilities, if told to do so.

  • Moor your boat if time permits.

  • Once you are in a safe place, follow your command’s protocols for personnel accountability and contact your command’s designated Point of Contact to check-in and report your location and situation.

  • When given the all clear, pre­pare to evacuate to a shelter or neighbor’s home if your home is damaged.

 


 

If Not Told to Evacuate

  • Stay tuned to radio, TV, and eMNS alerts.

  • Avoid elevators.

  • Seek shelter in a small interior room on the lowest level such as a bathroom, closet, or basement.

  • Stay away from glass, windows, and doors.

  • Lie on the floor under a table or another sturdy object.

  • Do not go outside until instructed to do so even if the storm is over and it seems calm. This could be the eye of the storm passing, and winds will pick up again.

 


 

If Told to Evacuate

  • Follow instructions and the guidelines given regarding times and routes.

  • Take only essential items and your emergency kit.

  • Turn off gas, electricity, and water if you have not already done so.

  • Disconnect all appliances.

  • Make sure your car’s gas tank is full.

  • Follow the designated evacuation plan and expect a high volume of traffic. 

  • Do not walk in moving water.

  • Do not drive in high water.

 


 

Who Should Evacuate

  • Mobile home or temporary structure residents

  • High-rise build­ing residents

  • Those who live on the coast, a flood­plain, near a river, or on an island waterway.

  • Those ordered to evacuated by authorities.

 


Set your own course through any hazard: stay informed, make a plan, build a kit. Live Ready Marine Corps.