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Severe Thunderstorm

Thunderstorms occur frequently during the afternoon and evening hours of Florida's hot, humid spring and summer months, but they can occur year-round and they are always dangerous.  Thunderstorms may occur singly, in clusters, or in lines, and typically produce very heavy rain for a relatively brief period, anywhere from 30 minutes to an hour. 

All thunderstorms have lightning, and the often torrential rain associated with a thunderstorm can cause rapid flooding in low-lying areas;  but these systems are classified as severe thunderstorms by the National Weather Service when they include the potential for one or more of the following: 

  • hail one inch or greater in diameter,

  • wind gusts in excess of 57.5 mph, or

  • a tornado.

 

Click HERE for the FEMA
Ready Business Severe Wind Toolkit
.

FEMA graphic indicating traits of severe thunderstorms, a powerful wind icon, cloud with lighting and hail icon, a flash flood and tornado icon
Graphic heading says Prepare Now in a Blue Circle
Graphic heading says Survive During the Hazard in Orange Circle
Graphic heading says Be Safe After the Hazard in Green Circle

Before

During

After

  • Keep your home "storm-ready."  Trim trees and branches near your house.  Ideally, no part of a tree should touch your home, and branches that hang over your roofline should be cut regularly.

  • Declutter drains and gutters.  Install plumbing check valves.  Consider installing a sump pump with a backup battery to handle flooding rains.   

  • Prevent potential mosquito breeding grounds.  Regularly clean birdbaths and water bowls; bring in or drain and cover  outdoor items. 

  • Consider having environmentally friendly larvicide like Dunks on hand to put into standing water after heavy rains to keep disease-causing mosquitoes from multiplying.

  • Check the local news or a NOAA Weather Radio forecast regularly to see if you're at risk for severe weather. 

  • Sign up for Severe Thunderstorm Warnings through the AlertNassau notification system.

  • Pick a safe room in your home as your storm shelter - an interior room (with no windows) on the lowest floor where people and pets can go when severe thunderstorm warnings are issued.  A bathroom or closet can protect you from flying debris.

  • If you have time before severe weather hits, secure loose objects, close windows and doors, and move any valuable objects inside or under a sturdy structure.

  • Encourage your loved ones and neighbors to prepare for severe thunderstorms

  • If you have time before the severe weather hits, secure loose objects, close windows and doors, and move any valuable objects inside or under a sturdy structure.

  • Continue to listen to local news or a NOAA Weather Radio to stay updated.

  • When a Severe Thunderstorm Warning is issued, damaging wind or large hail are approaching, Shelter-In-Place:  

    • At Home - Go to an interior room (with no windows) on the lowest floor.  Take your pets with you.

    • At Work or School - Stay away from windows.  Do not go to large open rooms such as cafeterias, gymnasiums or auditoriums.  

    • Outside - Go inside a sturdy, site-built structure immediately.  Sheds and storage facilities are not safe.  Taking shelter under a tree can be deadly - it puts you at a greater risk of getting struck by lightning and the tree, or heavy branches, may fall.

    • In a Vehicle - Being in a vehicle during severe thunderstorms is safer than being outside; however, drive to the closest secure shelter if there is sufficient time.

  • Continue listening to local news or a NOAA Weather Radio to stay informed - more severe thunderstorms could be headed your way.

  • Let your family and close friends know that you're okay.  Text messages are  more reliable than phone calls.

  • After the severe weather threat has ended, check your property for damage.  Stay out of damaged buildings.  Wear long pants, a long-sleeved shirt and sturdy shoes to walk through damage and debris.  Don't let pets walk around in debris.

  • Contact local authorities if you see power lines down. 

  • If your home is damaged, take photographs and contact your insurance agent.  Beware of people who drive up and offer to repair your property.

  • Check on your neighbors.  If you come across someone who is injured, provide first aid (if you are trained and able) and call 9-1-1 to alert emergency responders.

National Weather Service Graphic describing Watch versus Warning.  A Thunderstorm Watch issued when a severe thunderstorm is possible, be prepared!  A Thunderstorm Warning is issued when one is happening nearby, take shelter immediately!
Storm-Ready Home

Keep Your Home "Storm-Ready"

Indoors during thunderstorm.jpg
Thunderstorms.png
Image with helpful tips on keeping your home storm ready
Graphic illustrating safe behavior after a storm; stay inside until it has passed, be aware of downed power lines, keep away from flood water, only run generators more than 20 feet from the home.
when thunderstorms appear.jpg
when thunderstorms appear.jpg
Clickable Facebook logo link to Nassau County Florida Emergency Management's Facebook page
Clickable Twitter Logo Link to Nassau County Florida Emergency Management on x, formerly known as twitter

Nassau County Emergency Operations Center
77150 Citizens Circle  |  Yulee, FL  32097

Clickable link to WebEOC
Clickable image of Nassau County is Storm Ready linking to National Weather Service storm ready program webpage

Nassau County Emergency Management is committed to a continued effort to enhance and improve our website's accessibility for all audiences. 

If there are changes we can implement to make our website easier to use, or if you encounter material or services you cannot use, please email us at NCEM@nassauso.com

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