Department of Emergency Management and Security

CONTACT INFORMATION: Open during regular business hours 8 a.m. - 4:30p.m., Monday - Friday
4890 Alliance Drive, Suite 2200, Fairfax, VA 22030
Seamus Mooney


What It Is

Thunderstorms are large, localized weather events. Thunderstorms are most common in summer, but can occur in any season. All thunderstorms produce lighting and have the potential to produce tornadoes, strong winds, hail, wildfires, and flash flooding – the last of which is responsible for more fatalities than any other thunderstorm-related hazard.

Lightning is of particular concern because of its unpredictability – lightning often strikes beyond what is perceived to be the storm, sometimes occurring as far as 10 miles away from rainfall.

Thunderstorm Hazard Annex


Thunderstorm Hazard Annex

Click on the appropriate link below to download a PDF copy of the Thunderstorm Hazard Annex page from the Community Emergency Response Guide.

English (PDF) | Spanish (PDF) | Korean (PDF) | Arabic (PDF) | Mandarin (PDF) | Vietnamese (PDF)

Key Terms

  • A Thunderstorm Watch means there is a possibility of a thunderstorm in your area.
  • A Thunderstorm Warning means a thunderstorm is occurring or will likely occur soon.

What To Do

  • Sign up for Fairfax Alerts and have a battery or crank powered NOAA weather radio available.
  • Prepare your home by cleaning gutters and drains.
  • Remove dead or rotting trees or limbs that might fall.
  • Secure or bring inside any outdoor objects that could blow away or become “missiles” and cause damage.
  • Unplug any electronic equipment.
  • Know if your residence/business is in a designated floodplain.
  • Apply for flood insurance (note that FEMA flood maps do not reflect all risks from fast-moving flash or "sheet" flooding - they types that are often generated by heavy rains).
  • As the threat approaches, decide where you will go – can you make it indoors, or is an enclosed vehicle your best option?
  • Learn First Aid.
  • Refer to "Power Outage/blackout" and "Medical Emergency" hazard pages.

  • Upon seeing lightning or hearing thunder, immediately move indoors or into an enclosed vehicle.
  • Remain inside until 30 minutes after the last clap of thunder.
  • If you are driving in low visibility, try to safely exit the roadway and park. Stay in the vehicle and close the windows.
  • If you cannot get inside or reach a safe building, avoid high ground, tall or isolated trees, poles and masts, and large metal objects (including fences and bleachers).
  • If you are in open water, head to shore immediately.

  • Continue with activity or proceed where you are going when it is safe.
  • Check in with family and friends by texting or using social media.
Fairfax Virtual Assistant