How to build a marketing suppression list for disaster zones

A suppression list is just a set of addresses or regions you exclude from a campaign. For disasters, the useful unit is the ZIP code: you want to hold sends to areas currently affected by a wildfire, hurricane, flood, or emergency — and only those areas, only while it matters.

That sounds simple. In practice, most teams do it by hand, and by the time the list is ready the moment has passed. Here's where the DIY approach breaks, and how to build something that actually keeps up.

Why manual monitoring fails

• It's too slow. Someone has to notice the news, find the affected area, translate it into ZIP codes, and update the list — usually after the campaign already went out.
• It's too coarse.“Pause California” suppresses millions of unaffected people. A wildfire might touch 40 ZIP codes, not a whole state.
• It never expires. Hand-built lists tend to stay on long after the event ends, so you keep suppressing revenue from recovered areas.

The data sources that work

You don't need to scrape the news. Authoritative, structured, free government feeds already publish this:

• NWS / NOAA — live weather watches and warnings, tagged to county FIPS codes, updated continuously.
• FEMA — disaster and emergency declarations, which define recovery windows after the acute danger passes.
• USGS — significant earthquakes, with epicenter coordinates.
• IPAWS — the national alert system for civil emergencies.

The work is in the plumbing: normalizing each source, mapping county and polygon geographies down to ZIP codes, scoring severity consistently, and attaching an expiry to every entry.

Building it: step by step

• Define triggers. Which categories and severities suppress? (e.g. any wildfire; floods at warning level; ignore frost advisories.)
• Resolve to ZIPs.Convert county- and polygon-based alerts into the actual ZIP codes inside them. This is the step most homegrown attempts skip, and it's why they over-suppress.
• Set expiry windows. Active warnings clear on their own; aftermath windows (e.g. 21–45 days after a FEMA declaration) need an explicit decay so ZIPs rejoin automatically.
• Integrate at send time. Diff your audience against the live list right before the campaign goes out — not from a CSV you exported last week.

The shortcut

This is exactly what Zipawa does: it ingests those federal feeds every 15 minutes, fans county and polygon events out to ZIP codes, scores severity, and tracks timing windows so suppressions expire on their own. You can drop a ZIP list into the free checker to see your current suppressions immediately, or pull them programmatically from the suppressions endpoint.