Instruments · NTAS Monitor

The NTAS Monitor, in plain language.

A short, friendly introduction to the instrument — what it is, what it does, who it is for, and what it can and cannot tell you. If you only read one page about our national-alert work, this is the one.

What this system is

The NTAS Monitor answers one question: is the United States national terrorism alarm on, and how many times has it actually fired?

It exists because, until we built it, no public page anywhere answered that. The government runs one national terror-alert stream, but it publishes no tally of it — no running count of how many alerts have been issued, no history, no comparison across years. The alarm only shows you what is live right now. That means a quiet alarm and a broken alarm look exactly the same from the outside. This instrument tells the two apart.

What the alarm actually is

The stream is called the National Terrorism Advisory System (NTAS). It is run by the Department of Homeland Security, and it replaced the old colour-coded threat levels in 2011, then was redesigned in 2015 into two tiers:

• Bulletins — a general, elevated threat environment. Descriptive, not specific. These are the common case.
• Alerts — the sharp tier, reserved for a specific and credible threat. Since the 2015 redesign, DHS has issued zero of these.

Since December 2015 there have been 20 bulletins in total. The stream is thin and bursty: a cluster after an attack or a conflict, then long silence. Which is exactly why a count is worth having — the shape of the stream is the story.

What the monitor does

• Live status. Whether an advisory is in force right now, checked against the official DHS feed.
• The count. Bulletins by year, so you can see the pattern rather than one moment.
• The full timeline. Every bulletin on record back to December 2015, with its active window.
• The channel map. Every related public stream — DHS, FBI, NCTC, FEMA, State Department and more — with which ones the public can read and which ones anyone actually counts.
• An honest link to the source. A button straight to the raw DHS feed, so you never have to take our word for it.

What it is good for

This is a public instrument, so it is built for anyone who needs the real record rather than a feeling. In practice we see it applying to:

• Journalists and researchers — a citable count and timeline instead of "there have been several alerts this year."
• Security and risk teams — a fast check on the national picture before a briefing, plus the reminder that "no alert" is a baseline, not an all-clear.
• Analysts and students — a worked example of the gap between what a government body publishes and what it actually tallies.
• The curious public — plain-language context the next time a "terror alert" headline lands and you want to know whether anything actually changed.
• Anyone doing due diligence on a claim — if someone says the alert level is up, this page shows the receipts in one click.

What it will not do

Honesty is the whole point, so here is the short list of limits:

• It does not predict anything. It reports what was issued, not what might come.
• It does not cover classified or law-enforcement-only streams. It works from open sources only.
• It does not fake liveness. Where the page cannot reach a live source from inside a sandbox, it links you to the raw feed instead of pretending to poll it. An honest link beats a dead heartbeat.
• It does not track people. It is a tally of public bulletins, nothing else.

How to use it

1. Open sid-ntas-monitor.surge.sh.
2. Read the status line first — that is the current state of the alarm.
3. Scan the count and the timeline for the pattern you actually need.
4. Click through to the official DHS feed whenever you want the source itself.
5. If your question is not answered by the page, send it to us. The instrument grew out of a real question, and it can grow again.

Everything here is free and public. If the work is useful and you want to help keep the shelf standing, there is a campaign on the home page. Donating changes nothing about what you can read.