Typhoon Preparedness Print


A typhoon is a type of tropical cyclone, or severe tropical storm. They form in almost all ocean basins and in this area of the Pacific, it is called a Typhoon. A typical cyclone is accompanied by thunderstorms, and in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface (clockwise in the Southern Hemisphere).

In the Pacific and Indian Oceans, typhoons can affect all land masses from Asia to the Middle East to Australia. The Western Pacific typhoon season begin on May through October.

Typhoons can cause catastrophic damage to coastlines and several hundred miles inland. They can produce winds exceeding 155 miles per hour as well as tornadoes and microbursts. Additionally, typhoons can create storm surges along the coast and cause extensive damage from heavy rainfall. Floods and flying debris from the excessive winds are often the deadly and destructive results of these weather events. Slow moving hurricanes and typhoons traveling into mountainous regions tend to produce especially heavy rain. Excessive rain can trigger landslides or mud slides. Flash flooding can occur due to intense rainfall.


Typhoon Preparedness Checklist

  • Put togerther a basic disaster supplies kit and consider storage locations for different situations
  • Protect yourself and family a communications and emergency plan
  • Know your surroundings
  • Learn the elevation level of your property and whether the land is flood-prone, which will help you know how your property will be affected when storm surge or tidal flooding are forecasted
  • Identify levees and dams in your area and determine whether they pose a hazard to you
  • Learn community hurricane evacuation routes and how to find higher ground
  • Determine where you would go and how you would get there if you needed to evacuate
  • Make plans to secure your property:
  • Cover all of your home's windows with permanent storm shutters or 5/8 inch marine plywood, cut to fit and ready to install (tape does not prevent windows from breaking!)
  • Install straps or additional clips to securely fasten your roof to the frame structure
  • Be sure trees and shrubs around your home are well trimmed so they are more wind resistant
  • Clear loose and clogged rain gutters and downspouts
  • Reinforce your garage doors; if wind enters a garage it can cause dangerous and expensive structural damage
  • Plan to bring in all outdoor furniture, decorations, garbage cans and anything else that is not tied down
  • Determine how and where to secure your boat
  • Install a generator for power outages
  • If in a high-rise building, be prepared to take shelter on or below the 10th floor
  • Consider building a safe room

    During a Typhoon

  • Listen to the radio or TV for information, and keep your weather radio handy
  • Secure your home, close storm shutters and secure outdoor objects or bring them indoors
  • Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed
  • Turn off propane tanks
  • Avoid using the phone, except for serious emergencies.
  • Moor your boat if time permits.
  • Ensure a supply of water for sanitary purpose such as cleaning and flushing toilets: fill the bathtub and other larger containers with water
  • Find out how to keep food safe during and after and emergency

    You should evacuate under the following conditions:

  • If you are directed by local authorities to do so, and be sure to follow their instructions
  • If you live in a mobile home or temporary structure—such shelters are particularly hazardous during hurricane no matter how well fastened to the ground
  • If you live in a high-rise building—hurricane winds are stronger at higher elevations
  • If you live on the coast, on a floodplain, near a river, or on an island waterway
  • Read more about evacuating yourself and your family. If you are unable to evacuate, go to your wind-safe room. If you do not have one, follow these guidelines:

  • Stay indoors during the hurricane and away from windows and glass doors
  • Close all interior doors, secure and brace external door.
  • Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm, and winds will pick up again
  • Take refuge in a small interior room, closet or hallway on the lowest level
  • Lie on the floor under a table or another sturdy object
  • Avoid elevators.



    Tropical Depression Once a group of thunderstorms has come together under the right atmospheric conditions for a long enough time, they may organize into a tropical depression. Winds near the center are constantly between 20 and 34 knots (23 - 39 mph).

    Tropical StormOnce a tropical depression has intensified to the point where its maximum sustained winds are between 35-64 knots (39-73 mph), it becomes a tropical storm. It is at this time that it is assigned a name. During this time, the storm itself becomes more organized and begins to become more circular in shape -- resembling a typhoon.

    The rotation of a tropical storm is more recognizable than for a tropical depression Tropical storms can cause a lot of problems even without becoming a typhoon. However, most of the problems a tropical storm cause stem from heavy rainfall.


    There are two Tropical Storm Conditions in the CNMI:

    1) Tropical Storm Condition 2 or "Weak Tropical Storm" has a maximum sustained winds (MSW) of 30-49 MPH (26-43 knots) with a peak gust of 40-64 MPH (33-56 knots).

    2) Tropical Storm Condition 1 or "Severe Tropical Storm" has a maximum sustained winds (MS) of 50-73 PH (44-63 knots) with a peak gust of 65-94 MPH (57-81 knots). 


    TyphoonAs surface pressures continue to drop, a tropical storm becomes a typhoon when sustained wind speeds reach 74 MPH (64 knots). A pronounced rotation develops around the central core.

    Typhoons are Earth's strongest tropical cyclones. A distinctive feature seen on many typhoons and are unique to them is the dark spot found in the middle of the typhoon. This is called the eye. Surrounding the eye is the region of most intense winds and rainfall called the eye wall. Large bands of clouds and precipitation spiral from the eye wall and are thusly called spiral rain bands.

    Typhoons are easily spotted from the previous features as well as a pronounced rotation around the eye in satellite or radar animations. Typhoons are also rated according to their wind speed on the Saffir-Simpson scale. This scale ranges from categories 1 to 5, with 5 being the most devastating. Under the right atmospheric conditions, typhoons can sustain themselves for as long as a couple of weeks. Upon reaching cooler water or land, typhoons rapidly lose intensity.


    There are 5 Typhoon Categories:

    1) Typhoon Category 1 or "Minimal Typhoon"  has a maximum sustained winds (MSW) of 74-95 MPH (64-82 knots) with a peak gust of 95-120 MPH (82-105 knots). 

    2) Typhoon Categroy 2 or "Moderate Typhoon" has a maximum sunstained winds (MSW) of 96-110 MPH (83-95 knots) with a peak gust of 121-139 MPH (106-121 knots).

    3) Typhoon Category 3 or "Strong Typhoon" has a maximum sustained winds (MSW) of 111-129 MPH (96-112 knots) with a peak gust of 140-164 MPH (122-142 knots). 

    4) Typhoon Category 4 or "Very Strong Typhoon" has a maximum sustained winds (MSW) of 130-156 MPH (113-136 knots) with a peak gust of 165-198 MPH (143-173 knots).

    5) Typhoon Category 5 or "Devastating Typhoon" has a maximum sustained winds (MSW) of 157-194 MPH (137-170 knots) with a peak gust of 199-246 MPH (174-216 knots. 




    Based on information received from the Joint Typhoon Warning Center (JTWC), Joint Region Marianas (JRM), CNMI Office of Homeland Security & Emergency Management Agency (OHS & EM) will set conditions based on the time destructive winds (50 knots) or greater are expected to reach the CNMI:



    The CNMMI is in CONDITION 4 year round due to our location in typhoon alley, until a higher condition is set. It means any destructive winds could be upon us within 72 hours.


    WHAT SHOULD I DO?                 

    1. Maintain areas around the house clear of debris and loose material. 
    2. Dead branches should be pruned/removed from trees. 
    3. Determine location of official shelters (will be announced or posted the OHS & EM website).
    4. Stock and maintain your typhoon supply locker.
    5. Consider plastic trash cans with wheels for later personal items transport if evacuation is necessary.
    6. Have a personal list of ER and family telephone numbers to call.
    7. Copy important documents with originals in a safe place.
    8. Have a personal list of hotels and costs, accept pets?





    WHAT SHOULD I DO?               

    1. Clean/bleach and fill bathtubs, plastic trash cans (with wheels) with water
    2. Set refrigerator to coldest settings.
    3. Freeze water in jugs.
    4. Fill vehicle fuel tanks.
    5. Check your generator, test run it, have adequate fuel safely stored (see below)
    6. Get cash, ATMs may not work after the storm.
    7. Secure yard equipment, move plants inside.
    8. Protect electronics (bag, prepare to move to an interior room off the floor).
    9. Have a supply of rags and old towels.
    10. Double check your Typhoon Supply Locker.





    WHAT SHOULD I DO?               

    1. Close typhoon shutters if your home is equipped with it, otherwise board up all windows and doors.
    2. Unplug appliances
    3. Turn off gas valves
    4. Turn off main water valve
    5. Fill containers and your bathtub with clean water and keep them covered.
    6. Set refrigerator and freezer to their coldest setting and pack your freezer tightly with newspaper (This will keep your food colder longer).
    7. Secure cars: 1) Set your emergency break 2) Close all windows and doors tightly. 
    8. Move carpet and furniture away from windows.
    9. Consider evacuation to an official shelter if your home is not storm proof (will be announced on the local radio stations or visit the OHS & EM website).
    10. Complete your last errands then stay off the road.
    11. Stay tuned to local media broadcasts.






    1. Stay indoors
    2. Place towels/rags around leaky doors and windows 
    3. Conserve water.



    Wait for the ALL CLEAR message on the local media.


    AFTER ALL THE CLEAR IS GIVEN:                

    1. Look out for and do not touch dangling or downed power lines!! 
    2. Report them and broken water or sewage lines, and downed telephone lines to 911.
    3. Do not consume any food and water which might have spoiled or contamated
    4. Use stored or steralized water.
    5. Consider all water contaminated until it is declared safe by local authorities



    1. Place generator in a well ventilated location and away from combustible materials. 
    2. NEVER FUEL generator when it is running. 
    3. READ and REFER to Owner’s Manual for hook up procedures. 
    4. If using extension cords, consider running the cord along the walls avoiding heavy traffic areas. 
    5. Inspect cords for fraying, cracks or cuts. 
    6. NEVER lay power cord on wet or damp areas. 


    Last Updated on Tuesday, 16 August 2016 12:53