Grid Threat Monitor: Live NOAA Space Weather
Check the latest NOAA geomagnetic storm level, solar radiation activity and radio blackout readings. Follow the three-day outlook and build your household power-outage plan.
↓ View the Threat Level Build Your Outage Plan →Read the Scales Separately
The headline uses NOAA’s G scale, the indicator for geomagnetic storms and potential power-system effects. The separate S and R readings describe different hazards. They are not combined into an official “grid threat score.”
- G — Geomagnetic storms: potential effects on power systems, satellites and navigation.
- S — Solar radiation storms: effects on satellites, aviation and polar radio communications.
- R — Radio blackouts: disruption of high-frequency radio, particularly on the sunlit side of Earth.
Levels 1–5 mean minor, moderate, strong, severe and extreme. A value of 0 means none reported; a dash means missing data. The three-day outlook displays the G forecast and R/S probabilities, rather than treating probabilities as observed storm levels.
Review NOAA’s official scale definitions for potential impacts.
Space Weather and Household Readiness
Geomagnetic storms can induce currents in long conductors such as transmission lines. Their effects depend on the storm, location and power network. This monitor does not measure local outages or predict whether your household will lose power.
A solar storm is not a guarantee that every electronic device will fail. A Faraday bag does not keep the electrical grid operating. Focus your outage plan on lighting, safe backup power, water, food and ways to receive updates.
Read NOAA’s explanation of power-grid impacts and use our power-outage preparedness guide for household planning.
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More Live Tools & Readiness
- Live Threat Scanner — real-time earthquakes and severe-weather alerts.
- Power Outage Preparedness — build a complete household blackout plan.
- Best Emergency Lights — keep rooms, stairs and work areas safely illuminated.
- The Complete Preppers List — the full interactive checklist across every category.
- Emergency Food Supply Guide — calculate exactly how much your household needs.
- American Family Safety — cover every member of your household.
Grid Threat Monitor FAQ
Where do the readings come from?
The monitor fetches the latest observed R, S and G readings and three-day outlook from NOAA’s Space Weather Prediction Center. Planetary Kp comes from a separate NOAA product.
What does the main G number mean?
G is NOAA’s geomagnetic storm scale. Levels 1 through 5 indicate minor through extreme storms; 0 means none reported at that observation. A dash means the reading is unavailable. This is not a local outage measurement.
Why are the R and S readings separate?
Radio blackouts, solar radiation storms and geomagnetic storms affect different systems. A high R or S reading does not automatically mean the G scale is high or that your local power grid is failing.
What do the forecast percentages mean?
The outlook shows the chances of R1–R2 radio blackouts, R3–R5 radio blackouts and S1-or-greater radiation storms. G is shown as a forecast level. Forecast dates use UTC and are separate from latest observed readings.
How often does the monitor refresh?
The page checks NOAA every three minutes while the tab is visible and auto-refresh is enabled. Refresh checks immediately. Pause auto-refresh stops automatic checks; it does not pause activity at NOAA.
What happens if NOAA data is unavailable?
The monitor labels missing values as unavailable and retains older successful readings with a stale warning if a request fails. Observed scale readings older than one hour are also marked stale. Kp uses a six-hour freshness window because it is a three-hour index.
Does a high G level mean an outage is certain?
No. The G scale describes geomagnetic activity and possible impacts. It does not confirm an outage at your address. Check your utility and official NOAA updates alongside your household outage plan.
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