OrbAlert is launching soon. This page describes how the site will work; nothing here is live hazard information yet.
How OrbAlert works
OrbAlert gathers public hazard data from government agencies and a few curated sources and shows it on one map. It is not an emergency authority: its data can be late, incomplete or wrong, and it never replaces official warnings, evacuation orders or emergency services. Always follow local officials.
Who every item comes from
Every item carries a tag naming its source and what kind of source it is:
- OFFICIAL: issued by the agency responsible, such as the US Geological Survey or the National Weather Service.
- CURATED: collected from other sources by NASA's Earth Observatory (EONET).
- NEWS: news reports found by The GDELT Project. They are unverified, shown as hollow rings on the map, and never carry a severity.
Each feed is checked on its own schedule. When a check fails, the last good data stays up and is marked stale; it is never shown as current. The Sources page shows every feed's state live.
How severity is decided
OrbAlert never invents a severity. It uses the source's own level where there is one, and says which rule applied on every item.
| Source | Severity comes from |
|---|---|
| USGS | Earthquakes: the USGS PAGER alert when USGS has issued one (red extreme, orange severe, yellow moderate, green minor). Otherwise magnitude: 7.0 or more extreme, 6.0 severe, 4.5 moderate, smaller minor. Every quake from the last 24 hours, plus magnitude 4.5 and above from the past 7 days. |
| USGS Volcanoes | The volcano alert level for hazards on the ground: warning extreme, watch severe, advisory moderate. The aviation colour code is shown too, and used only if no alert level is set. US volcanoes only. |
| NWS | The severity the National Weather Service gives each alert (extreme, severe, moderate, minor). US only. |
| NOAA NHC | A tropical cyclone's maximum sustained wind: 111 mph or more (category 3+) extreme, 74 mph (hurricane) severe, 39 mph (tropical storm) moderate, lower minor. Atlantic and eastern and central Pacific. Forecast cones, tracks and points come from NOAA's tropical map service; a cone shows where the storm's centre will probably go, not the storm's size. While a storm is active, OrbAlert also shows NHC's chance of 39, 58 and 74 mph winds, when 39 mph winds could arrive, coastal watches and warnings and each storm's wind field, and NHC's outlook of where storms could form; My Home turns these into a briefing for each threatened place. The map can also show every model's track ("spaghetti") from NHC's public guidance file, including the 30 ensemble members: those are models, not forecasts, and where they disagree the forecast is less certain. |
| NOAA Tsunami | The warning centre's message category: warning extreme; threat and advisory severe; watch moderate; information statements and cancellations minor. Only the latest bulletin from each of NOAA's two centres, dropped after 24 hours without an update. |
| NOAA River Gauges | The NWS flood category, observed or forecast, whichever is worse: major flooding extreme, moderate flooding severe, minor flooding moderate, action stage minor. US gauges only. |
| NIFC WFIGS | No severity published, so none is shown. US wildfire perimeters; prescribed burns are left out. |
| NASA EONET | No severity published, so none is shown. Worldwide wildfires, storms, volcanoes and ice; items already covered by an official feed above are left out. |
| GDELT | News is never given a severity. |
"No matching hazards" is not an all-clear
My Home lists hazards inside or near each saved place. When nothing matches, it says "No matching hazards in the checked feeds" and never "safe": the feeds can miss things, and if any feed is not current the check is marked incomplete.
What isn't covered
- Weather alerts and river flooding outside the United States.
- Air quality and wildfire smoke.
- Local evacuation orders, road closures and which shelters are open now.
- Tsunami messages from centres other than NOAA's, such as Japan's.
- Earthquakes below magnitude 4.5 after 24 hours, and any older than 7 days. Radar covers the US only.
News reports
Every 15 minutes OrbAlert reads GDELT's newest batch of news articles and keeps one only if it is tagged with a concrete natural hazard and its headline names that hazard. A news pin appears only at a city the headline itself names; other reports appear as "News coverage" on a matching official event. News is kept for 48 hours.
Nearby help
Hospitals, clinics and shelters come from a monthly copy of OpenStreetMap, listed by volunteers, so opening hours, services and even whether a place still operates can be out of date. Call ahead if you can. In an emergency, call your local emergency number.
Privacy
- Saved places stay in your browser. To check one, the page sends its coordinates, rounded to about 100 m, in the body of a request (never in the address), and the server keeps no record of them.
- Share links contain only public event ids, never a place of yours.
- There are no accounts, ads or trackers. The map loads base-map tiles from OpenFreeMap and, if you turn radar on, images from NOAA; those services see your IP address, as any website you visit does.
Storms that passed here before
Each My Home card says how many tropical storms and hurricanes have passed within 60 miles of that place, the closest few, and how strong the strongest was as it went by. This comes from NOAA's HURDAT2 record (Atlantic since 1851, eastern and central Pacific since 1949) and is history only: it says nothing about what a current storm will do, and a place with no past storms is not a safe place.
On a slow connection
The text version lists active storms and every extreme or severe item as plain text, with no map and no scripts. It is the same for everyone, so it stays quick when a storm sends traffic up.
Units and data
Screens use US units (miles, °F, mph, inches, feet). The JSON API is metric. Every source and its licence is listed on the Sources page.