To interpret a US terrorism advisory, open the official notice and read its dates, scope and recommended actions. The five-color Homeland Security Advisory System belongs to the history of US public warning. Current federal terrorism-advisory information is published through the National Terrorism Advisory System, or NTAS.
From five colors to descriptive notices
The Homeland Security Advisory System introduced in 2002 used five conditions: green for Low, blue for Guarded, yellow for Elevated, orange for High and red for Severe. A color chart circulating today may be historical material. In 2011, the Department of Homeland Security replaced that system with NTAS, as explained in its NTAS questions and answers.
Use the official NTAS page for the current status and notices. A screenshot can omit an expiration date, and a search result can lead to an archived notice. Check the original document before forwarding a warning or changing plans.
Understand the notice type
| Format | Meaning | Reader's next step |
|---|---|---|
| Bulletin | Broader developments or trends concerning terrorism threats | Read the context and any actions relevant to your setting. |
| Elevated Alert | A credible terrorism threat, with more general information about timing or target | Identify the affected area, audience and official instructions. |
| Imminent Alert | A credible, specific and impending terrorism threat | Follow the notice and relevant local emergency instructions. |
Those labels summarize a notice's purpose. The text supplies the information needed to decide how it applies to you. DHS explains that alerts have expiration provisions and may be updated, extended or canceled as information changes. Reopen the official page when relying on a saved copy.
Read the notice in five passes
- Issuer and location: confirm the document is on the official DHS site. Distinguish the federal notice from a local agency's instructions.
- Time: record the issue date, any update and the expiration or review information. Include a time zone if one is given.
- Scope: identify the places, sectors, activities or audiences actually named. A nationwide bulletin may discuss a pattern without naming your particular event.
- Evidence and uncertainty: distinguish what authorities report from possibilities or concerns described in conditional language.
- Actions: copy the relevant instructions accurately and follow the appropriate official local or organizational channel.
Practice with a fictional forwarded notice
A friend forwards a cropped image headed “Elevated Alert.” Its date and bottom paragraph are missing. You find the matching notice on DHS.gov and discover that its stated period has ended. Your response is to share the official link with that date context, then check the current NTAS page. The old notice helps explain a past situation; it cannot establish today's status.
In a second fictional case, an active notice discusses a particular sector. Your workplace coordinator checks the complete notice and local agency guidance, identifies the actions that apply to the site and tells staff where updates will appear. Staff receive a clear procedure and contact, rather than an unexplained forwarded image.
Use the right reporting and information channels
DHS's reporting guidance directs people to local law enforcement for suspicious activity and to 911 for an emergency in the United States. It asks for concrete observations: what or whom you saw, when, where and why the activity caused concern. Describe behavior and circumstances accurately; speculation about someone's identity or beliefs does not establish a threat.
Keep your own safety first and follow emergency instructions. A general terrorism advisory does not give a member of the public authority to confront, search or detain someone. For a workplace or event, know the designated reporting contact and where official updates will be posted before a stressful situation arises.
Share enough context to prevent confusion
When sharing a notice, include the official link, issue date, relevant scope and the specific passage or action you want recipients to read. Clearly label your own interpretation. If an update changes the instructions, correct the earlier message through the same channel so people can distinguish the versions.
A manageable routine is to check the current official page when a notice affects a decision, verify any local instructions and record what you acted on. This guide deliberately links to the live status instead of freezing a claim about whether an advisory is active.
Return to the security library for guides to travel preparation, workplace responsibilities and physical security planning.