Understanding Tropical Weather Watches and Warnings
If you live in an area threatened by tropical storms and hurricanes, it’s important to know what all the watches and warnings mean and how to prepare for them.
What Is the Difference Between a Watch and a Warning?
One of the most important things to understand when inclement weather is imminent is the difference between a watch and a warning. The National Hurricane Center (NHC) states a watch is when the weather conditions can be favorable for a risk. It is vital to be on guard and begin preparing your family and home once a watch is in affect. A warning, according to the NHC, means you should take immediate action, such as evacuating safely.
The NHC also states a tropical storm or hurricane watch is issued 48 hours before anticipated onset of tropical storm- or hurricane-force winds. A tropical storm or hurricane warning is issued 36 hours before the onset of tropical storm- or hurricane-force winds, adds the NHC.
What to Do During a Watch or Warning
Ready.gov offers the following tips on what to do when preparing for a tropical storm or hurricane watch and warning.
- Monitor weather conditions with a battery-powered NOAA weather radio. This will help ensure you receive the most up-to-date information, including forecasts and additional watches or warning, even if there’s a power outage.
- Review your evacuation plan.
- Keep extra cash on hand and fill your gas tank in case you need to evacuate quickly.
- Keep emergency supplies, blankets and sleeping bags with you and fill all prescriptions in case you need to evacuate quickly.
- Bring in outdoor furniture, trash bins and anything else that is not tied down. Loose objects can easily become projectiles in high winds.
- Gather supplies for securing windows with shutters or plywood.
- Follow instructions from local officials. If you’re ordered to evacuate, do so immediately.
- Put valuables and important records in a waterproof container and take it with you.
- Set your refrigerator to its maximum cold level and keep the door shut (to help prevent your food from spoiling in the event of a power loss).
- Secure windows with shutters or plywood.
- If you must evacuate, turn off utilities, unplug appliances and lock doors and windows before leaving.
Know Your Tropical Weather Definitions
There are many weather terms and definitions out there, and it can be quite confusing to keep them all straight. The NHC and Hurricanes: Science and Society define the following tropical weather terms:
A low-pressure, warm-core system with an organized wind circulation that forms over tropical (and sometimes subtropical) waters. Classified based on sustained surface winds, types of tropical cyclones are: tropical disturbance, tropical depression, tropical storm or hurricane.
- Tropical Disturbance: Unorganized systems of thunderstorms with very little wind circulation. Typically originates in the tropics but occasionally forms in the subtropics.
- Tropical Depression: A tropical cyclone with maximum sustained surface winds of 38 mph or less. A tropical depression may form slowly from a tropical disturbance.
- Tropical Storm: A tropical cyclone with maximum sustained surface winds of 39 to 74 mph.
- Hurricane: A tropical cyclone with sustained surface winds greater than 74 mph. Hurricanes are classified into the following five categories based on wind speed:
- Category 1: 74 to 95 mph
- Category 2: 96 to 110 mph
- Category 3: 111 to 129 mph
- Category 4: 130 to 156 mph
- Category 5: 157 mph or greater
Understanding the difference between a hurricane or tropical storm watch and warning is crucial. Now, you have the knowledge to be better prepared the next time you’re facing inclement tropical weather.
Originally published on September 11, 2014.