MUSCATINE, Iowa – Severe thunderstorms are officially defined by the National Weather Service as storms that are capable of producing hail that is an inch or larger (capable of damaging property such as plants, roofs, and vehicles) or wind gusts over 58 mph (capable of breaking off large branches, knocking over trees, or causing structural damage to trees).
!["Severe]("/ImageRepository/Document?documentId=29489")
Some severe thunderstorms can produce hail larger than softballs, winds over 100 mph, tornadoes, dangerous lightning, or heaving rain that can cause flash flooding.
A Severe Thunderstorm Watch is issued when severe thunderstorms are possible in and near the watch area.
A Severe Thunderstorm Warning is issued when severe weather is reported by trained spotters or by radar.
The following tips for preparing for a tornado and tips for staying safe during a tornado are provided by ready.gov and the National Weather Service:
- Know your risk. Severe thunderstorms can occur year-round, at any hour, and throughout the United States.
- Sign up for your community’s warning system. The Emergency Alert System (EAS) and NOAA Weather Radio also provide emergency alerts. If your community has sirens, then become familiar with the warning tone.
- Pay attention to weather reports. Meteorologists can predict when conditions might be right for severe weather.
- Create a communications plan. Have a family plan that includes an emergency meeting place and related information. If you live in a mobile home or a home without a basement, identify a nearby safe building you can get too quickly, such as a church or family member. Check more ideas for your family plan at Ready.Gov/Make A Plan.
- Prepare your pets for disasters. They are an important member of your family, so they need to be included in your family’s emergency plan. Tips to help prepare for evacuation of your pet can be found at Plan for your pet.
- Identify and practice going to a safe shelter. Pick a safe room in your home, such as a basement, storm cellar, or an interior room on the lowest floor with no windows. A safe room built using FEMA criteria or a storm shelter built to ICC 500 standards can also be built.
- Prepare for long-term stay at home or sheltering in place by gathering emergency supplies, cleaning supplies, non-perishable foods, water, medical supplies and medication.
- Help your neighbor. Encourage them to prepare for the possibility of tornadoes.
Thunderstorm Information Sheet (PDF)