Hurricane (Tropical Cyclone)

A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain or squalls. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane (/ˈhʌrɪkən, -keɪn/),[1][2][3] typhoon (/taɪˈfuːn/), tropical storm, cyclonic storm, tropical depression, and simply cyclone.[4] A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".[4]

"Tropical" refers to the geographical origin of these systems, which form almost exclusively over tropical seas. Most of these systems will form over very warm waters. Therefore, they intensify. "Cyclone" refers to their winds moving in a circle,[5] whirling round their central clear eye, with their winds blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. The opposite direction of circulation is due to the Coriolis effect. Tropical cyclones typically form over large bodies of relatively warm water. They derive their energy through the evaporation of water from the ocean surface, which ultimately recondenses into clouds and rain when moist air rises and cools to saturation. This energy source differs from that of mid-latitude cyclonic storms, such as nor'easters and European windstorms, which are fueled primarily by horizontal temperature contrasts. Tropical cyclones are typically between 100 and 2,000 km (62 and 1,243 mi) in diameter.

The strong rotating winds of a tropical cyclone are a result of the conservation of angular momentum imparted by the Earth's rotation as air flows inwards toward the axis of rotation. As a result, they rarely form within 5° of the equator.[6] Tropical cyclones are almost unknown in the South Atlantic due to a consistently strong wind shear and a weak Intertropical Convergence Zone.[7] Also, the African easterly jet and areas of atmospheric instability which give rise to cyclones in the Atlantic Ocean and Caribbean Sea, along with the Asian monsoon and Western Pacific Warm Pool, are features of the Northern Hemisphere and Australia.

Coastal regions are particularly vulnerable to the impact of a tropical cyclone, compared to inland regions. The primary energy source for these storms is warm ocean waters. These forms are therefore typically strongest when over or near water, and weaken quite rapidly over land. Coastal damage may be caused by strong winds and rain, high waves (due to winds), storm surges (due to wind and severe pressure changes), and the potential of spawning tornadoes. Tropical cyclones also draw in air from a large area—which can be a vast area for the most severe cyclones—and concentrate the precipitation of the water content in that air (made up from atmospheric moisture and moisture evaporated from water) into a much smaller area. This continual replacement of moisture-bearing air by new moisture-bearing air after its moisture has fallen as rain, which may cause extremely heavy rain and river flooding up to 40 kilometres (25 mi) from the coastline, far beyond the amount of water that the local atmosphere holds at any one time.

Though their effects on human populations are often devastating, tropical cyclones can relieve drought conditions. They also carry heat energy away from the tropics and transport it toward temperate latitudes, which may play an important role in modulating regional and global climate.

Taken from  https://en.wikipedia.org/wiki/Tropical_cyclone 

• Storm Surge Warning: There is a danger of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 36 hours. If you are under a storm surge warning, check for evacuation orders from your local officials.
• Hurricane Warning: Hurricane conditions (sustained winds of 74 mph or greater) are expected somewhere within the specified area. NHC issues a hurricane warning 36 hours in advance of tropical storm-force winds to give you time to complete your preparations. All preparations should be complete. Evacuate immediately if so ordered.
• Tropical Storm Warning: Tropical storm conditions (sustained winds of 39 to 73 mph) are expected within your area within 36 hours.
• Extreme Wind Warning: Extreme sustained winds of a major hurricane (115 mph or greater), usually associated with the eyewall, are expected to begin within an hour. Take immediate shelter in the interior portion of a well-built structure. 
• Storm Surge Watch: There is a possibility of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 48 hours.
• Hurricane Watch: Hurricane conditions (sustained winds of 74 mph or greater) are possible within your area. Because it may not be safe to prepare for a hurricane once winds reach tropical storm force, The NHC issues hurricane watches 48 hours before it anticipates tropical storm-force winds.
• Tropical Storm Watch: Tropical storm conditions (sustained winds of 39 to 73 mph) are possible within the specified area within 48 hours.
•  Tropical Weather Outlook: The Tropical Weather Outlook is a discussion of significant areas of disturbed weather and their potential for development during the next 5 days. The Outlook includes a categorical forecast of the probability of tropical cyclone formation during the first 48 hours and during the entire 5-day forecast period. You can also find graphical versions of the 2-day and 5-day Outlook at www.hurricanes.gov and www.weather.gov/cphc  
• Tropical Cyclone Public Advisory: The Tropical Cyclone Public Advisory contains a list of all current coastal watches and warnings associated with an ongoing or potential tropical cyclone, a post-tropical cyclone, or a subtropical cyclone. It also provides the cyclone position, maximum sustained winds, current motion, and a description of the hazards associated with the storm.
• Tropical Cyclone Track Forecast Cone: This graphic shows areas under tropical storm and hurricane watches and warnings, the current position of the center of the storm, and its predicted track. Forecast uncertainty is conveyed on the graphic by a “cone” (white and stippled areas) drawn such that the center of the storm will remain within the cone about 60 to 70 percent of the time. Remember, the effects of a tropical cyclone can span hundreds of miles. Areas well outside of the cone often experience hazards such as tornadoes or inland flooding from heavy rain.

Taken from  https://www.weather.gov/safety/hurricane-ww 

 Hurricane Preparedness Steps

PREPARE NOW

• Know your area’s risk of hurricanes.
• Sign up for your community’s warning system. The Emergency Alert System (EAS) and National Oceanic and Atmospheric Administration (NOAA) Weather Radio also provide emergency alerts.
• If you are at risk for flash flooding, watch for warning signs such as heavy rain.
• Practice going to a safe shelter for high winds, such as a FEMA safe room or ICC 500 storm shelter. The next best protection is a small, interior, windowless room in a sturdy building on the lowest level that is not subject to flooding.
• Based on your location and community plans, make your own plans for evacuation or sheltering in place.
• Become familiar with your evacuation zone, the evacuation route, and shelter locations.
• Gather needed supplies for at least three days. Keep in mind each person’s specific needs, including medication. Don’t forget the needs of pets.
• Keep important documents in a safe place or create password-protected digital copies.
• Protect your property. Declutter drains and gutters. Install check valves in plumbing to prevent backups. Consider hurricane shutters. Review insurance policies.

• Turn on your TV or radio in order to get the latest weather updates and emergency instructions.
• Restock your emergency preparedness kit. Include food and water sufficient for at least three days, medications, a flashlight, batteries, cash, and first aid supplies.
• Plan how to communicate with family members if you lose power. For example, you can call, text, email or use social media. Remember that during disasters, sending text messages is usually reliable and faster than making phone calls because phone lines are often overloaded.
• Review your evacuation zone, evacuation route and shelter locations. Plan with your family. You may have to leave quickly so plan ahead.
• Keep your car in good working condition, and keep the gas tank full; stock your vehicle with emergency supplies and a change of clothes.
• If you have NFIP flood insurance, your policy may cover up to $1000 in loss avoidance measures, like sandbags and water pumps, to protect your insured property. You should keep copies of all receipts and a record of the time spent performing the work. They should be submitted to your insurance adjuster when you file a claim to be reimbursed.

• Bookmark your city or county website for quick access to storm updates and emergency instructions.
• Bring loose, lightweight objects inside that could become projectiles in high winds (e.g., patio furniture, garbage cans); anchor objects that would be unsafe to bring inside (e.g., propane tanks); and trim or remove trees close enough to fall on the building.
• Cover all of your home’s windows. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” exterior grade or marine plywood, cut to fit and ready to install.

• Turn on your TV/radio, or check your city/county website every 30 minutes in order to get the latest weather updates and emergency instructions.
• Charge your cell phone now so you will have a full battery in case you lose power.

• If you’re not in an area that is recommended for evacuation, plan to stay at home or where you are and let friends and family know where you are.
• Close storm shutters, and stay away from windows. Flying glass from broken windows could injure you.
• Turn your refrigerator or freezer to the coldest setting and open only when necessary. If you lose power, food will last longer. Keep a thermometer in the refrigerator to be able to check the food temperature when the power is restored.
• Turn on your TV/radio, or check your city/county website every 30 minutes in order to get the latest weather updates and emergency instructions.

Taken from  https://www.ready.gov/hurricanes 

 HURRICANE SAFETY 

• If told to evacuate, do so immediately. Do not drive around barricades.
• If sheltering during high winds, go to a FEMA safe room, ICC 500 storm shelter, or a small, interior, windowless room or hallway on the lowest floor that is not subject to flooding.
• If trapped in a building by flooding, go to the highest level of the building. Do not climb into a closed attic. You may become trapped by rising flood water.
• Listen for current emergency information and instructions.
• Use a generator or other gasoline-powered machinery outdoors ONLY and away from windows.
• Do not walk, swim, or drive through flood waters. Turn Around. Don’t Drown! Just six inches of fast-moving water can knock you down, and one foot of moving water can sweep your vehicle away.
• Stay off of bridges over fast-moving water.

Taken from  https://www.ready.gov/hurricanes 

 HURRICANE SAFETY 

• Listen to authorities for information and special instructions.
• Be careful during clean-up. Wear protective clothing and work with someone else.
• Do not touch electrical equipment if it is wet or if you are standing in water. If it is safe to do so, turn off electricity at the main breaker or fuse box to prevent electric shock.
• Avoid wading in flood water, which can contain dangerous debris. Underground or downed power lines can also electrically charge the water.
• Save phone calls for emergencies. Phone systems are often down or busy after a disaster. Use text messages or social media to communicate with family and friends.
• Document any property damage with photographs. Contact your insurance company for assistance.

Taken from  https://www.ready.gov/hurricanes