Kīlauea Eruption Explained: Episodes, Alert Levels and Vog
Nov 9, 2026
Kīlauea's summit eruption comes in short bursts of lava fountaining separated by pauses of weeks. This is how the Hawaiian Volcano Observatory reports each stage.
Guides
Plain-English explainers: what magnitude, alerts, AQI, hurricane categories and volcano alert levels mean, and where the official information comes from.
How to Read the Hurricane Cone: What the NHC Forecast Cone Shows
Nov 9, 2026
The cone is a map of forecast error for the storm's center. Here is how NHC sizes it for 2026, what the new map adds, and which NHC products show wind, surge and rain instead.
Cascadia Subduction Zone: The 1700 Earthquake and Future Risk
Nov 9, 2026
Cascadia's last great earthquake struck on a winter night in 1700 and was dated with tree rings and Japanese tsunami records. Here is what the USGS and Oregon officials say about the next one.
Tornado Watch vs Tornado Warning: What Each Alert Means
Nov 9, 2026
Watches come from the Storm Prediction Center, warnings from your local National Weather Service office. Here is how the tornado alert levels stack up, from a routine watch to a tornado emergency.
Aftershocks Explained: How USGS Aftershock Forecasts Work
Nov 9, 2026
After a strong earthquake, USGS publishes the odds of more shaking. Here is what foreshocks, mainshocks and aftershocks are, how long sequences last and how to read the forecast table.
Red Flag Warning vs Fire Weather Watch: What Each Alert Means
Nov 9, 2026
How the National Weather Service defines its two fire weather alerts, why the criteria differ from Colorado to Hawaii, and how fire agencies and SPC outlooks fit in.
GDACS Alerts Explained: What Green, Orange and Red Mean
Nov 9, 2026
GDACS, run by the European Commission and the United Nations, gives major disasters around the world a color. The colors are impact estimates for responders, not warnings for people in the area.
Wildfire Smoke and Air Quality: How to Read AirNow’s Smoke Map
Nov 9, 2026
How the AirNow Fire and Smoke Map works, why monitors and sensors on the same street can disagree, and the smoke guidance EPA and CDC give, quoted with attribution.
Largest Earthquakes in US History: The USGS Top 10 List
Nov 9, 2026
Nine of the ten largest earthquakes in US history struck Alaska. Here is the full ranking from the USGS catalog, with the largest outside Alaska and what the official records say about each.
How Hurricanes Are Named: Rotating Lists and Retired Names
Nov 9, 2026
Who picks the names, why the 2026 list returns in 2032, which Atlantic names were retired after the 2020 to 2025 seasons, and what happens when a busy season runs out of names.